The Last of the Hybrids - Kenwood TS-830s

 Hybrid Goodness

A good friend dropped off a radio and mic that he had received from a SK.  It is a Kenwood TS-830s, which according to the serial number was manufactured December 1980.  

The TS-830s was the last of the Hybrid's manufactured by Kenwood.

The Golden Age of the Hybrid: Best of Both Worlds?

If you've spent any time scouring the used market for a "new-to-you" HF rig, you’ve likely bumped into the Hybrids. For those of us who love the glow of a filament but appreciate the reliability of solid-state components, these rigs represent a very specific, nostalgic era of amateur radio engineering.

So, what exactly makes a rig a "Hybrid"?

It’s all about the hand-off between technologies. These transceivers aren't "all-tube" in the boatanchor sense, nor are they fully solid-state like the modern SDRs sitting on our desks today. Instead, they used semiconductors for the heavy lifting in the low-level circuits—think oscillators and IF stages—while saving the vacuum tubes for the "muscle."

The Magic Formula: 12BY7 + 2x 6146B

Almost every classic hybrid followed a predictable, battle-tested recipe. If you pop the hood, you’re almost guaranteed to find this exact lineup:

The Driver: A single 12BY7 tube.

The Finals: A pair of 6146s.

This combination was the "Goldilocks" setup for the 1970s ham. It reliably pumped out about 100 watts—plenty of PEP to work the world from a modest backyard wire.

Why the 6146?

The 6146 wasn't just common; it was "The Finals Tube." It was rugged, relatively inexpensive, and offered great linearity. It’s the reason so many of these rigs are still on the air today.  NOS tubes are still available for less than $70/each.

You’ll find this exact "Hybrid" DNA across the most legendary gear of the era:

The Kenwood Line: From the TS-520 through the TS-820 and 830S (widely considered the pinnacle of the hybrid age).

The Heathkit "Hot Water" Series: The ubiquitous HW-100 and HW-101.

The SB-Series: The refined SB-101 and SB-102 "Green Giants."

There is just something satisfying about the "warm-up" period and the manual "Tune & Load" process that a modern rig can't replicate. It forces you to actually interact with your station. Plus, let's be honest—the smell of tubes in the shack is worth at least 3dB of "feel-good" gain.

Image of Finals from another site

Do old electrolytic capacitors always need replacement?

If you’ve spent any time on the forums or at a local hamfest, you’ve heard the mantra: "Friends don't let friends power up vintage gear without a recap." While there is some wisdom there, if we are being honest with our soldering irons, not all "old" capacitors are created equal.

In fact, there’s a strong argument to be made that the electrolytic caps found in a 1980 Kenwood TS-830s are actually more reliable than the junk found in 1990s consumer electronics.

Here is the breakdown of why "older" often meant "sturdier" in the world of vintage RF gear.

1. The "Capacitor Plague" of the 90s

The primary reason 70s and 80s caps get a bad rap is that people lump them in with the "Capacitor Plague" of the late 90s and early 2000s. During that era, a massive industrial espionage blunder led to a faulty electrolyte formula being used across the industry.

These 90s caps didn't just drift in value; they were "time bombs" that would bulge, leak corrosive fluid, and fail catastrophically within just a few years. By contrast, the Japanese-made caps from the 70s and early 80s (like those from Nichicon or United Chemi-Con) were over-engineered and built with stable, well-understood chemistry.

2. Physical Size and Heat Dissipation

In the 70s and 80s, we weren't trying to fit a transceiver into a pocket. Components were physically larger. A 1000µF capacitor from 1980 is often twice the size of a modern equivalent with the same rating.

Surface Area: Larger cans dissipate heat better.

Electrolyte Volume: More physical space meant more electrolyte fluid. Since the primary failure mode of an electrolytic is the fluid drying out over decades, having more "juice" to start with gave these old components a much longer runway.

3. Operating Margins

Back in the "Hybrid" glory days, engineers weren't shaving every penny off the Bill of Materials. If a circuit needed a 25V capacitor, you’d often find a 35V or 50V part in there just for the headroom.

Modern manufacturing in the 90s moved toward "just enough" specs. When you run a capacitor right at its voltage or temperature limit, its lifespan drops exponentially. Those beefy 70s components were often "loafing" along, which is why you can still find 50-year-old Heathkits that hold a steady voltage.

The "Don't Be Reckless" Disclaimer

While those 70s and early 80s caps were built like tanks, physics eventually wins. Even the best electrolyte will eventually dry out or the rubber seals will perish.

If you're bringing a rig out of a 20-year slumber, don't just "flip the switch." Use a Variac to slowly reform the capacitors. 

That being said, my friend had already purchased replacement caps so I went ahead and replaced the 500V HV caps because the originals showed an arc-over and spattered solder from sometime in the past.

Original HV caps

See the solder splash and arc-over on the lead to the left 500v cap?

Replaced

Replaced with modern caps

When you go to replace these old caps you realize they don't make 'em like they used to. The old beefy "can" capacitors had four tall, sturdy solder posts. Kenwood designers used those extra lugs as convenient tie-points, daisy-chaining multiple wires for the high-voltage rails and ground returns directly onto the capacitor itself.

But the modern replacement is a "snap-in" style cap with two tiny, stubby pins designed for a PCB, not a bundle of 18-gauge hookup wire.

Trying to cram three or four vintage wires onto one miniature modern post was not fun.  I ended up using the leads of the bleed resistor as solder posts.

Finally on the air after a rookie mistake

After replacing the caps I tested the voltage at the caps and all seemed good.  I buttoned it up and attempted to tune into a dummy load while watching an amp meter to see if the rig was drawing the prescribed current... and found that I had no bias current. 

I freaked out!  No bias means the tubes run wide open and turn into oven elements.    

I took everything back apart and started tracing the bias circuit. It simply had no power. I calmed down and thought "How could replacing the HV caps have crippled the bias current?".  Well it shouldn't.  Then I vaguely recalled brushing a switch on the back of the radio as I had turned it over.  What is that switch?  The manual calls it the "Screen Grid Switch" and apparently it's used when neutralizing the tubes, or some such hollow-state magic that I never learned to do.  What I did learn is that if it's switched off, you ain't got no bias current, or any other current needed to test transmit.  

Whew! Panic averted.

Operation

The "Tune-Up" Dance

If you’re coming from the world of modern "no-tune" solid-state rigs, the front panel of a vintage hybrid will have some controls with unfamiliar names like DRIVE, LOAD, PLATE, CARRIER, etc. Before you throw your callsign out there, you have to perform the "Tune, Dip, and Load" ritual.

This isn't just for nostalgia; it’s about matching the high impedance of those vacuum tubes to your 50-ohm antenna system and bringing the tank circuit into resonance. Skip this step, and you aren't just risking "band splatter"—you’re asking those precious 6146B finals to cook themselves to death.

The Warm-Up: Low Power into the Dummy Load

Never tune up "live" on the air if you can help it. I always start by switching over to a dummy load. After a good look at the manual, I set the mode to TUNE, the meter to ALC, and set the CARRIER knob to about a quarter turn.

With the DRIVE knob centered, I flipped the switch to SEND. I peaked the DRIVE and tweaked the CARRIER until the meter stayed happily within the ALC range, then flipped back to REC. This gets our low-level stages talking to the finals without stressing the tubes.

The "Dip": Finding Resonance

Next comes the most satisfying part of hybrid operation: Dipping the Plate.

1. Set the meter to IP (Plate Current).

2. Pre-set the PLATE knob to the segment of the band I’m targeting.

3. Flip to SEND and carefully sweep the PLATE control until the needle "dips" to its lowest point.

This "dip" is the signal that your circuit is in resonance. You want to center the needle right at the bottom of that valley and flip back to REC quickly—tubes don't like sitting in a non-resonant state for more than a few seconds!

Putting "Fire in the Wire"

Now that we’re resonant in low-power mode, it’s time to give those 6146s their legs. I switched the mode from TUNE to CW to get the full HV (High Voltage) on the plates.

Keep an eye on that plate current! You want to stay at or below 265mA. Use the CARRIER knob to keep the drive power in check.

I noticed something interesting during this stage: the LOAD peaked at a different spot in full power than it did in the low-power TUNE mode. This required another quick "re-dip" of the PLATE. Some folks say a shifting peak like that points to a "soft" 12BY7 driver tube, but since I’m seeing a solid 100 Watts out on 40m and 30m, I’m not ready to convict the driver just yet.

It’s quite a process compared to pushing a button on a modern rig, but there’s a soul to this machine that makes every contact feel earned.

On-Air Performance and Operating Impressions

Voice Operations on 40m

I started by making several Phone contacts on the 40-meter band. Audio reports were positive, and the rig stayed stable on frequency. Before getting on the air, I spent some time balancing the gain between the D-104 microphone and the radio’s internal mic gain. To do this, I monitored the meter in ALC mode while watching the RF output on my dummy load to ensure I wasn't over-driving the gain.

CW Operations on 30m

Moving up to 30 meters for some CW, I sent out a single call—primarily to check my frequency on the Reverse Beacon Network (RBN). I was immediately answered by KB6UN. We had a productive 25-minute ragchew discussing antennas, hamfests, and vintage gear. The TS-830S performed admirably throughout the contact.

---

Operating Oddities

While the TS-830S is feature-rich compared to my Ten-Tec Century/21 or Heathkit HW-101, it has several design quirks that take some adjustment.

CW Offset and Tuning

On a modern transceiver, the VFO display typically indicates your actual transmit frequency. On the TS-830S, the transmit frequency is offset by 800 Hz from the indicated frequency. This may be common in older gear, but without a digital VFO on my other vintage rigs, the offset is much more apparent here.

Zero-Beating Without a Filter

The sidetone on this rig is fixed at 800 Hz. While you can use the RIT to adjust the listening frequency, you must be careful not to do so until you have zero-beat the other station. Unlike my modern rigs, there is no "spot" function or visual indicator for zero-beating.

On my HW-101, the sharp 250 Hz CW filter helps peak the signal when you are on frequency. Since this TS-830S lacks a narrow CW filter, I have to rely on a manual tone-match:

1. Switch the gain knob to turn off break-in mode.

2. Hold down the key to hear the internal 800 Hz sidetone.

3. Match the pitch of the incoming signal to that sidetone.

Interestingly, in CW mode you have to turn the IF SHIFT to approximately the 10 o'clock position for USB bands or 2 o'clock for LSB bands to see the RF meter peak at a zero-beat.  The manual attempts to explain this but it was quite confusing initially until I learned to do that. Additionally, since this radio predates built-in keyers, you’ll need an external unit or a mechanical key. The jack is wired for a standard "tip = dit" configuration and has about 65 volts on the key line so be careful if you do try to use a modern keyer circuit.

The AF/Sidetone Conflict

My primary complaint involves the sidetone volume. In this design, the sidetone level is tied directly to the AF (audio frequency) gain control. I prefer to operate with the RF gain turned down and the AF gain turned up to manage band noise, but this makes the sidetone deafeningly loud during transmission.

Currently, I have to manually turn the AF gain down before every transmission and back up to listen. I am planning to research a modification to separate the sidetone level from the main volume control to make CW operation more practical.

Filtering and Narrow-Band Operation

This transceiver predates the era of Digital Signal Processing (DSP), relying entirely on analog circuitry and crystal filters. While the TS-830S offered optional crystal filters for CW, this particular unit is only equipped with the standard SSB crystal filter. There is no digital noise reduction or sharp audio peaking for CW signals.

What this rig does provide—which was likely a novel feature at the time—is a Variable Bandwidth Tuning (VBT) control. This allows you to linearly narrow the IF bandwidth down to approximately 500 Hz with a 6 dB slope. It is certainly not "sharp" by modern standards; even with the bandwidth dialed all the way down, I can still hear stations within 2 kHz of my frequency.

To help manage interference, the radio includes:

• Adjustable Notch Filter: Useful for knocking down a specific nearby CW carrier.  Note that when the notch filter is at 12 o'clock that is approximately 1500 hz above the receive frequency.  If you're trying to use it in CW mode it's somewhat trial and error to find the offending signal.

• IF Shift: This allows you to move the passband relative to the signal to further reject adjacent QRM.

While these controls are effective for an analog design, they are a far cry from a modern rig like my Yaesu FT-DX10. On the Yaesu, I can achieve a razor-sharp focus on a single CW signal and essentially make the rest of the band disappear. On the hybrid, you are always operating with a much wider "window" into the RF spectrum.

The things I like

Thermal management and fan noise

One thing I immediately noticed about the TS-830S is how quiet the fan is. Despite the fact that the vacuum tubes generate a significant amount of heat—essentially operating at "oven" levels during long ragchews—the fan is variable speed and remains very quiet even when moving a large volume of air.

I have complained about the fan noise on my FT-DX10 numerous times. Operating the Kenwood reminds me of the design choices Yaesu has made with their modern rigs; simply mounting a standard muffin fan on the back is a far less sophisticated solution compared to the integrated thermal design found in this older equipment.

Sound

The TS-830S is technically a dual-conversion transceiver utilizing two intermediate frequencies: 8.83 MHz and 455 kHz. However, its architecture differs from the traditional "Collins type" designs, like the older TS-520. In the TS-830S, the bandwidth of both IF stages is narrowed simultaneously during VBT operation. Because of this specific implementation, it essentially functions like a single-conversion transceiver with an 8.83 MHz IF.

Despite the lack of modern filtering, the receiver is very pleasant to listen to. In fact, other than the volume control issue I mentioned previously, the sidetone on this rig sounds far better than the raspy, digitized sidetone on my Yaesu FT-DX10.

The audio out of the case is excellent.  It has a very good speaker that is well isolated, and can go to high volumes without distorting.  The case itself has felt / damping materials where edges mate with other panels, to reduce resonance.  It is nicely designed. Speaking of the case itself, it is thick metal.  Not car ramp thick, but sturdy, not bendy.

There is a definite appeal to switching off the modern SDR rigs and their "super-filtered" audio. Sometimes it’s worth returning to a simpler design that down-converts RF to the audible range without sending the signal through light-years of digital processing before it reaches your ears.

Little things

Having a built-in power supply is nice, especially since it would require a multi-voltage external supply like my HW-101 if it was not built in.

The controls are well laid out.  After just a couple minutes of operation everything fell to hand without searching for the control

Lastly, the VFO moves with the perfect amount of resistance. For a radio that is 46 years old that doesn't appear to have visited a service center (there are no service stickers), to have a reduction drive geared VFO that operates this smoothly, again speaks to the quality of manufacture of these old Kenwoods.

Conclusions

I plan to spend more time with the rig.  Hopefully, I can record some QSOs so that folks who began operating with more modern rigs can see what it's like to get on the air with these beauties. 

They don't make them like they used to.

This is NOT a QRP rig, so I won't offer my normal "Lower your power and raise your expectations", but I will say "Sometimes traveling the older paths leads you to a new revelation"

That's all for now

73 

AA4OO Rich

Oscilloscope now on the bench

Tektronix 475 Oscilloscope and Android Signal Generator App

When I was debugging problems with my Ten-Tec Century/21, and especially my problematic one-watter kit, I needed to see more than DC voltages.  I carried my problem stuff to my friend Paul to see what his scope and signal generator revealed. 

Why would a ham need a scope?  Audio and RF are both AC (alternating current) and a voltmeter alone doesn't offer much insight into that world of voltage across time and phase.

I almost bought an inexpensive digital scope last year, then thought better of it.  Then I almost bought a featured digital scope and checked my wallet and thought better of it. A good digital scope in the 100 Mhz and up range from reliable sources costs upwards of $500.  On the other hand, older professional scopes that have been well maintained and kept in calibration are excellent choices and will last a lifetime.  You do give up handy on screen cursors for measurements, so you have to count divisions by hand and do the math.  You also don't have digital storage in a digital scope, but smart phone cameras and video can make up for that.  

When I saw this recently calibrated Tektronix 475 listed in the classifieds on eHam.net for a nice price, I decided it was time to step into the world of visualized AC.

Watching a capacitor charge 250 times a second
The lines are a bit wide because the signal source was noisy

Tek 475 Specs

The Tektronix 475 is a portable (30 lbs), dual-trace oscilloscope with dual time-bases similar to the 465, but with 200 MHz bandwidth and a maximum vertical sensitivity of 2 mV/Div. It is all solid-state except for the CRT. It was introduced in November 1972.  

This scope cost $3,000 when it was new.  Now you can find them in good condition for less than $200.

• Bandwidth --  200 MHz (475), AC cutoff 10 Hz, switchable BW limit 20 MHz
• Rise time -- 1.75 ns (475)
• Deflection -- 2 mV/Div to 5 V/Div, 1-2-5
• Cascaded mode -- 400 μV/Div, 50 MHz with CH1 input connected to CH2 VERT SIG OUT
• Time base -- 10 ns/Div to 500 ms/Div, 1-2-5, and ×10 magnifier
• Input impedance -- 1 MΩ // 20 pF
• Triggering -- 0.3 Div (int) or 50 mV (ext) to 40 MHz, increasing to 1.5 Div/250 mV at 200 MHz; AC coupling >60 Hz; LF REJ >50 kHz, HF REJ <50 khz="" li="">
• X bandwidth -- 3 MHz
• Z axis input -- 5 Vp-p, 50 MHz
• Calibrator -- 1 kHz, 30 mA / 300 mV square wave
• Outputs -- CH2 Vert Signal Out, 20 mV/Div into 1 MΩ or 10 mV/Div into 50 Ω; A and B +GATE OUT, +5 V; Probe power jack
• CRT -- 8 × 10 cm², P31 phosphor (P11 opt.)
• Power -- 110, 115, 120, 220, 230 or 240 VAC ±10%, 48-440 Hz, max. 100 W

Real knobs and switches

One advantage of an analog scope is that there is a labeled switch or knob for every function. No need to dig through menus to figure out how to do something.  To me this is the a true advantage to finding a well calibrated, analog scope.

An oscilloscope needs a function generator

An scope let's you visualize AC within a circuit, but when you testing  something you often need to inject AC into that circuit.  That's the role played by a function generator.  Function generators allow you to choose a frequency and a wave type (sine, triangle, square, etc.), or sweep across frequencies.

In general, the higher the frequency they support the more they cost.

If you have a mobile device you can get one that uses your headphone jack as output up to 22 kHz for free...

For a free app it is very nice.  It outputs sine waves very well, triangle waves are a bit soft pointed and square waves are for entertainment purposes only.  But it is free so I won't complain.  In the image below you can see the oscillations as it tries to generate a square wave but the audio amplifier of the mobile device just doesn't have that kind of control.

Frequency Generator App set to 1 kHz

Square Wave?

Square waves are not

Reduce the time base to zoom in

Yea, square wave.... not so much

The square wave is bad but sine and triangle waves look good until the frequency get's near the top of the range or the amplitude is raised too high.

Sine Waves look good

Triangle waves are on as well until you go up in frequency

The free app is inadequate for bench testing

While I appreciate that this would be a useful, portable signal generator for testing audio circuits, I'll be ordering a purpose-built function generator because generating clean square waves is an important test signal to be clean.  I also will need a generator that works above audio frequencies, hopefully up the the IF frequencies of the some of the equipment I'm testing.

Only the beginning

Having an oscilloscope is a new adventure for me.  I have another 1-watter kit ready to build that I've been holding off on because I wanted a scope for troubleshooting.  In the meantime I'm using the scope to watch transistors trigger and measure the timing circuits I'm building and learning how to control the scope.  The Tektronix 475 is a feature-rich analog scope.  If you plan to fix your own equipment or do some homebrew electronics work a scope can come in handy.

That's all for now

Sow lower your power and sample it with a scope

72/73
Richard AA4OO

The Heathkit HW-101 lives again

Ah, the sweet smell of hot tubes and resistors

Heathkit HW-101 after it's first QSO under new ownership

I completed my rebuild of my Heathkit HP-23B power supply this morning.  There was a bit of frustration on my part as I followed the instructions because they only have photos of a HP-23 which has adjustable bias and no LV switch.  

It left me scratching my head a couple times, and I had to locate a schematic of a HP-23B to complete the work.

Heathkit HP-23B Schematic

I really need to learn more about electronics

In the midst of the rebuild I thought I had a problem with the transformer.  Both low voltage winding taps (275v and 350v) showed very low resistance (about 5 Ohms) to chassis ground, which led me to believe there was a short in the transformer.  

I called my mentor in all things Ham radio, Paul AA4XX, and described the issue.  He walked me through the schematic and had me unsolder a couple points to confirm his guess that all was well.  That double tap, low voltage winding presents very low resistance to ground but it is not a short in the world of AC.  I continue struggling to wrap my head around the differences in AC and DC, but I'm slowly learning and fortunately haven't caught anything on fire yet.

Out with the old, in with the new

Old components

Testing High Voltage

My Multi-meter can only measure up to 600v, so in order to measure the 800v output I used two 3 watt 100 kOhm resistors in series as a voltage divider.  When in use, the MM will read half the voltage.

Voltage divider for measuring the high-voltage output

With the voltage divider the HV power measured 401v which works out to 802v undivided

Completed upgrade

The kit places all the components in the base and the holes that the old big filter capacitors used to be in are now just ventilation.  I need to put a wire shield over those holes because high voltages are present just below, as well as some really hot resistors.  With the top cover back on it, there shouldn't be a problem but the wire mesh shield is still recommended, especially if it's to be used inside a Heathkit speaker, where the top cover is not used.

With the PCB board, all the components are out of sight in the base except the big resistors

Replaced the HW-101 antenna connector with a BNC

Original antenna connector was a RCA with questionable integrity.

Original RCA antenna jack (viewed from inside chassis)

Replaced with BNC jack which fits without enlarging the original hole.

New antenna jack

The old radio now has power 

I replaced the old paper 350v 20uF electrolytic capacitors in the HW-101 and then connected the power cable and switched it on via the switch in the HW-101.  I didn't hear any audio at first and thought something was wrong.  Silly me, those tubes need a bit to warm up.  After a minute I was hearing audio and used the built-in crystal calibrator to check the VFO dial.  It was pretty close to spot on.

I ran through some initial checks according to the Heathkit manual.  Receive worked well.  I listened to some SSB and then dropped down to the 40m CW portion of the band and listened to CW.  I waited about 30 minutes for the tubes to warm up.  I didn't hear any drift on CW stations I was monitoring.

I found an open frequency, checked the plate current and then tuned up, outputting only about 10 watts because I don't know what state of alignment the finals are in yet.  This is the first time I've tuned a tube rig and that was interesting.  You have to peak the preselector in receive mode first, then when in tune mode, quickly work back through the preselector, final tune and load levers to peak the RF output.  It reads more complicated than it actually is.  My OCFD antenna has about a 1.7:1 SWR on 40m so it didn't need much tweaking from the initial settings.

I tuned around and answered N4PGJ, Ron in NY, and had a brief WES exchange.  The relay control time set by VOX delay needs to be bumped up a bit as it was dropping between every word break, but other than that it worked like a charm.

I'll make a video soon, but initial impressions are positive.  The audio quality was astoundingly good, and the CW filter really did a much better job than I expected.  It has a very pleasant sine-wave sidetone rather than the raspy square wave sidetone of my Ten-Tec Century/21.  I really think I'm going to enjoy using this old rig.

UPDATE

I got the rig buttoned up and on the desk.  Here's a video...

Oldie but goodie

That's all for now

So lower your power and warm up those tubes.

72/73

Richard AA4OO

Before transistors there were TUBES

Oh Boy, what have I gotten myself into

TUBES

A few months after re-entering the hobby in 2015 I picked up a TenTec Century/21.  It has been one of my favorite radios to operate and it is the most aesthetically pleasing radio I own.  After working with it's older (circa 1977) discrete transistorized technology and debugging some of it's problems, I became interested in building kits to learn about electronics.  I built a number of radio kits from different sources and some of the mini-module kits from Elecraft.

But I kept wondering about tube radios.  I came to the hobby well past the tube radio era and although I've read a lot about valve technology I didn't have any first hand experience.  I kept watching auctions for old Heathkits and Military radios and even bid on a few but lost the bids.

This past Christmas I decided that in 2018 I'd do something about this lingering interest.  I knew I'd eventually want to operate one mobile because, well that would certainly make it harder.  The power requirements of tubes are orders of magnitude greater than the QRP transistorized rigs I'd purchased.  Not knowing what I was doing I figured I could re-work an old Heathkit HP-13 power supply to give me what I'd need for an old military radio like the GRC-9.  

Heathkit HP-13a

Unsurprisingly, I was the only bidder and got one for $30 along with the odd grove power connectors that it uses. But I didn't do my research, and soon learned that the magic for these high voltage power supplies lies in the very specific design of their transformers.  In the case of the HP-13 it is operated much like an old military vibrator power supply with two germanium transistors acting as the vibrator.  Current is applied to to the core until it saturates and then a specific voltage determined by the number of turns is generated, the saturation drops the current to that winding and it starts over with the other transistor and the other winding.  I couldn't easily, or practically lower the 800v high voltage down to 580v required by the military radio I wanted and even the low voltage windings produce 300v and 250v respectively which is far beyond the 105v needed by the military radio.

I was warned off actually purchasing a military vibrator power supply due to a number of issues so I decided I'd start out with the radio this supply was designed for, a Heathkit HW-101.  All the electrolytic capacitors have to be replaced, and I plan to replace the diodes to be on the safe side as well.  I'm hoping the old transistors are still serviceable as I can't find any information on direct replacements for those.  I've ordered the replacement caps, diodes and resistors so I'll see how my refurb of this old power supply works out.  Working with voltages that can kill me is a bit daunting and I'm being very careful with the limited power-up tests I've performed so far.

Heathkit HW-101

That brings me to the newest arrival.  If you read my blog you know I like to do photography and it's no fun to photograph ugly radios so I kept watching auctions for HW-101s that were in good cosmetic condition.  I knew I'd have to do a good bit of refurbishment on whatever I ended up with but at least I could start with a "looker".

Heathkit HW-101

I plan, of course, to use it primarily for CW.  I'm aware that this radio is NOT particularly pleasant for CW due to the clacking relay as well as the poor filtering, but I've gotten accustomed to hearing lots of CW stations at once while working with my Century/21 so I think I can adapt.  All my other radios have full break-in so this will be a challenge to deal with, but I'm up to seeing what it was like for old time hams.

Crystal filter

While it has a crystal filter, 6dB of filtering at 400Hz will not offer much rejection to the out of band signals.  I guess I'll see. 

Admittedly this is far from QRP radio but I will endeavor to operate mobile at least a few times just for the experience.  I plan to operate at QRP levels to the extent I'm able.  There's just so much for me to learn.

If I don't maim myself or burn my house down, be on the lookout for posts as I resurrect the power supply and the old girl and get it on the air.  I have some ideas for photography involving glowing tubes that I think will be fun to figure out.  My bigger challenge is that I have no room for this thing at my operating position, so I'm trying to figure that out as well.

So drop me a line if you have restoration experience with these rigs.  Of course I'm reading what I can and look forward to learning how to align the transmit tubes and all the things I've had absolutely no experience with in the world of transistorized radios.

That's all for now

So warm up your tubes and raise your expectations

72/73

Richard AA4OO

Don't forget -- Straight Key Night 2018 is tomorrow !

Straight Key Night -- 2018

Don't forget January 1st, 2018 starting 00:00 GMT (7pm EST Dec 31) is the start of Straight Key Night 2018.  Bring your tired, old equipment on-air and mash your favorite mechanical key.  This is not a contest, just an opportunity to make lots of fun QSOs.

I'll be on the air with my 1977 Century/21 using my Junker Straight key and Standard Vibroplex Bug.

ARRL has details on their website... http://www.arrl.org/straight-key-night

Video from 2018 SKN

If you hang in there until the 2:08 mark you'll see my new, spiffy, dual camera angle recording method that I plan to use in all my videos.

So, lower your power, and raise your expectations...

72/73

Richard AA4OO

Thank you for my signal report

3 numbers can mean a lot

QRP operators strive to make the most out of a little.  So when we receive a signal report it means a lot to us.  But the common signal report, given using the R-S-T System, seems often to be misunderstood by some amateur radio operators.

RST has 3 elements:

• R stands for Readability.  How easy or difficult is it to copy the characters or words being sent on a scale from 1 to 5, with 1 meaning unreadable ranging up to 5 meaning perfectly copy-able.
• S stands for Signal Strength.  How strong is the signal on a scale from 1 to 9, with 1 being barely perceptible up to 9, being extremely strong.
• T stands for Tone.  This is only used to describe a CW signal's tone.  Given modern transceivers there are few cases where you'd send anything other than a 9 meaning perfect tone, devoid of ripple or modulation. You'll rarely hear a report with a Tone report other than 9, but if you hear ripple or modulation artifacts you may send lower numbers but it will likely just confuse the other operator.  If you hear chirp (a rising or falling tone) you may wish to append a 'C' to the RST to indicate that.

I want to concentrate on Readability and Signal strength.

Readability

I believe most of us are guilty of focusing on the signal strength portion of the report rather than readability.  But readability can convey a lot to the operator receiving the report.  

For instance if you have a lot of local noise or if the band is noisy due to magnetic disturbance or there's QRM or QRN readability may be difficult.  Similarly, if the operator is using poor technique and running letters or words together that affects readability.

It's possible that signal strength may be good or even moderately strong (6 or 7) but for some reason copy is difficult.  It would be worthwhile to send a 2 (Barely readable, occasional words distinguishable) or a 3 (Readable with considerable difficulty) for the 'R' portion of the signal report as in 359.  Then follow up with WITH QRM or WITH POOR SPACING, to make the other operator aware that you're having trouble copying.

I will occasionally have an operator send me a 3 for R but it seems to always be related to low signal strength.  If someone sends you a 3 or a 4 and it's not followed by an equally low signal strength number inquire as to the difficulty in readability.  It may be something you can correct on your end.

Signal

Signal seems obvious but it's not.  

I believe that many operators use the reading on their S-meter to report the Signal strength but different manufacturers calibrate their S-meters quite differently. The difference between S-units is supposed to be 6 dB but that's often not the case.  On many rigs the use of the preamp or the attenuator also effects the displayed S-meter reading.  So the S-meter is not an accurate reflection of what Signal strength is supposed to convey.  

My old Ten-Tec Century/21 doesn't even have an S-meter.  Neither do my homebuilt QRP radios.

So, what should we be using?  Well how about the actual meaning of the system:

1. Faint—signals barely perceptible
2. Very weak signals
3. Weak signals
4. Fair signals
5. Fairly good signals
6. Good signals
7. Moderately strong signals
8. Strong signals
9. Extremely strong signals

Obviously this is a subjective report, but on my KX3 my S-meter may read 2 when the signal actually sounds Good (6), so I send a 6 even though the meter reads 2.  If I were to send the other station the S-meter reading of 2 they'd assume I'm barely copying them, because I sent them a 529.

I think you can start to see the point.  Use the system as it was designed, before radios had S-meters and the Signal report will have more meaning to the station receiving the report.

My Ten-Tec C21 doesn't have an S-meter but it does have AF and RF gain controls.  I will commonly run my AF gain at a high level and use the RF gain to control the volume of the received signal.  This increases the SNR (signal to noise) and gives me a relative gauge of how strong the sender is.  If I have my RF gain turned all the way down and still clearly hear the other station they have an extremely strong signal (9).  If I have to turn my RF gain all the way up just to copy then the signal is very weak, or faint (2 or 1).  In between those extremes I offer a relative report based on the signal strength  I  am hearing.

So, use the system as it was intended

So, reconsider how you give a signal report.  Think about the original intent of the R-S-T System and you'll be conveying far more information in your report that may help the other station know for certain how they are being heard.

I start most QSOs at QRP levels.  If the other station sends me a report that is below a 5 in readability or a signal strength 5 or below I change antennas or raise power, if I'm able, to make their copy of my station more pleasurable, but if they send me a 599 when they are barely copying me or losing me in QSB then how can I know to make a change?

Maybe this is a radical idea but for my own operation I will strive to start sending more accurate reports and help the other station truly know how they are being copied.

That's all for now...

So lower your power and raise your expectations

72/73

Richard, AA4OO

http://hamradioqrp.com

2B Radio Parts replacement bumpers for Vibroplex keys

Rubber baby buggy bumpers

Sometimes I needlessly struggle with a problem because I'm cheap.

My Vibroplex Vibrokeyer was manufactured in 1960.  My Vibroplex Bug was manufactured in the mid 1970s.  In both cases the once flexible, non-skid rubber feet have since turned to hardened rubber fossils. In order to use the keys without them skating all over the desk I employ a variety of non-skid solutions, except for the obvious.

For some reason I seem to have to move stuff on my desk all the time.  I guess I'm never content and constantly reorganize the station and accessories.  Inevitably I misplace a rubber mat or some rubberized shelf liner sticks out from under a key in an unsightly manner. In general it makes the station look shoddy.

Fossil feet on a 1960 Vibroplex Vibrokeyer

Bring out the buggy bumpers

Enter '2B Radio Parts'.  

2B Radio Parts, provide replacement parts for Bugs, paddles for various makes of keys.  I ordered Replacement Vibroplex Bumpers (6 Bumper Pack).  I wasn't aware the 'feet' were called 'bumpers', but there you have it... I have new rubber baby buggy bumpers for my bug and vibrokeyer.

The 6 bumper pack replaced the feet on both keys.  In case you never noticed, many keys, including those made by Vibroplex, have 3 feet rather than 4.  It keeps the key from rocking on a surface that isn't entirely level or flat.

Parts is Parts

The replacement feet... err... bumpers from 2B, fit fine. They were nearly an exact match for the old feet on the 1970s bug but were a smidge taller and slightly different design than those on the 1960 Vibrokeyer.  The older key had a chambered, internal design that I'd guess had a bit more cushion back when it was new.  57 years later, the rubber foot is a brittle relic of its former self.

new bumper left, 1960 Vibrokeyer bumper right

new bumper left, 1960 Vibrokeyer bumper right

Ahhh, no more slip siding away

The old feet are simply held on by countersunk machine screws and the receiving holes in the new bumpers fit without a hitch.

Shod with new boots, shoes, feet, bumpers, whatever

My Vibroplex Bug has a more solid disposition as well now

The moral of the story is stop being cheap and buy some new feet!

That's all for now...  

So lower your power and raise your expectations

P.S.   Oh, speaking of which (lowering your power and raising expectations)... I was sending out my call on 7030 unsuccessfully a couple nights ago, for about 10 minutes.  I was using my TenTec Century/21 at 5 watts QRP and getting lousy spots on RBN (6 to 9dB SNR).  I decided to keep sending CQ a couple more minutes and was finally answered by S51MF, Franz in Slovenia, 4700 miles away.  You just never know what your QRP signal is going to net you.

72/73
Richard, AA4OO

http://hamradioqrp.com

CW tone comparison C21 to KX3

The old ways are sometimes best

This is a short one.  I haven't found much time lately to enjoy the hobby, but the past few evenings I've been firing up the old Ten-Tec Century/21 and just listening to CW while I tend to other duties.   Tonight, I managed to find time before dinner to have a brief ragchew with fellow SKCC member WV8DH (Dave in West Virginia) using my old rig.  It reminded me how much I enjoy the sound of CW coming out of that radio.

I was too lazy to set the camera up to capture the QSO, but after the QSO I dropped down the band to find a good ragchew going on and grabbed my smartphone and shot a quick comparison of the CW tone presented by the 40 year old TenTec radio and my new, modern, Elecraft KX3. 

After listening to the video I realize that a lot of wonderful sound, including harmonics are not captured by the microphone on the phone and can't be heard in the video.  Nonetheless, I think you'll agree that the older rig has finer CW audio. It's certainly more pleasant to listen to for long stretches.  The KX3 audio still wears me out if I operate more than an hour.  I wrote a detailed post comparing the KX3 to the Ten-Tec Eagle last year that pointed out what I believe the culprit of the tainted audio on the KX3.  The Eagle is presently off the desk and if anything the older Ten-Tec Century/21 sounds even better than the newer Ten-Tec Eagle.

But here's the brief, badly made smartphone video comparison of the C21 and the KX3...

Comparing CW tone from TenTec C21 to a modern Elecraft KX3

That's all for now.  I'm going to be reviewing a nice bug that a friend has loaned me soon.

That's all for now...

So lower your power and raise your expectations

72/73 Richard  AA4OO

Hard fought SKCC QSO using the Ten-Tec Century/21

Sometimes you need to move your QSO

My ever changing station configuration
Left to right - Elecraft KX3, Ten-Tec Century/21 with Ten-Tec Eagle on top, the MFJ 493 keyer on the right
4 keys - Navy Flameproof, Kent Hand Key, Vibroplex Bug, N3ZN QRP paddle
The Elecraft AF1 audio filter is sitting unused in front of the Century/21

After starting our QSO the ARRL QST program started right on top of us causing QRM that forced us to move to another frequency

My old Ten-Tec Century/21 is a lot of fun to use and its direct conversion receiver makes CW sound beautiful. But the frequency dial is fairly imprecise so when I asked the station to QSY up 1kHz finding him again was a bit of a challenge.  When I heard him I had to zero-beat him again to make sure I was on the correct side of the direct conversion receivers passband.

Enjoy the QSO and the QRM dodging...

Shooting this video

This video was a bit harder to shoot than what I normally do.  I usually place my camera to one side but I wanted to use my fisheye lens and shoot the QSO from above.  

While shooting I was straddling the tripod with the camera right in front of my face so I was reaching around the tripod to use my keys and get to my keyboard for logging.  It was a bit awkward, and in the video you'll see me bump the VFO while trying to operate the radio because I couldn't really see what I was doing.  It's always fun to add a level of difficulty while making these videos.

That's all for now...

So lower your power and raise your expectations

72/73

Richard AA4OO

http://hamradioqrp.com

Quirky Keyer - The MFJ-493

The MFJ-493 has some cool tricks and some not so cool flaws

MFJ-493 "Super" Menu Driven Memory Keyer

Memory keyers do the repetitive and boring stuff

The bands have not been kind in this declining sunspot cycle and I've been sending out my call repeatedly on occasions before receiving a response.  I wanted to get a memory keyer to lessen the burden of repeatedly sending my call and to also give me opportunities to do a bit of contesting this year.

If you want a good memory keyer, the K1EL Winkeyer is the natural choice to go with, so of course, I chose to acquire a 23 year old MFJ product instead.   

Take the road less traveled and you'll find wonders or fall in a ditch, I always say

The MFJ-493 is no longer sold but you'll frequently see them available used for reasonable prices and MFJ still sells a less featured variant (the MFJ-492).

Memory keyer at the the ready

Features

Typical of many memory keyers the MFJ-493 let's you store messages in up to 8 memories of 4,000 character each using your paddle, an external keyboard plugged into the back or a terminal program via the serial interface.  If you make a mistake while entering a message you can send 8-DITS and it will erase the previous word and send the last word in the message so editing is fairly easy.  Messages can be constructed from other memories, i.e. you can store your call in Memory #1 and then use "/1" in other messages to reference your call.  Repeats and timers are available within the messages as well.

Any of the 8 messages can be sent with the press of a button, although to send messages 4-8 you switch to the second bank of memories.

I won't list all the features because I think they are relatively common across memory keyers and I've posted a link to the manual later in the post, but I will mention that I enjoyed the ability to vary the character AND word spacing sent in messages.  So you can create "Farnsworth" type messages that sound (to my ears) far more natural than the typical "squashed" sounding CW sent from most memory keyers.  I demonstrate that in the video review.   I know a contester would never want to slow down the CW sent from his memory keyer but I have different priorities.

Most of the functions are clearly visible on the front panel so you don't need to refer to the manual to operate most features.  Some of the commands are not listed on the front panel so don't totally ignore the manual.

Back panel

The back panel sports a couple interesting ports.. an external keyboard interface and a serial port interface.  The external keyboard can of course be used to generate Morse code without a paddle and can make programming memories easier.

The serial port can be used with a terminal emulator like PuTTY set to:

• 1200 baud
• 8 data bits
• 1 stop bit
• no parity
• xOn/xOff flow control.

If you power up the keyer while it's attached to a terminal emulator you can see some interesting information:

MFJ-493 MEMORY KEYER VERSION 1.1.2C.        COPYRIGHT MFJ ENTERPRISES, 1993.

TYPE "[help]" (USING BRACKETS AND LOWER CASE LETTERS) FOR ON LINE HELP INDEX.

[help]

HELP INDEX FOR MFJ-493 MEMORY KEYER

1.  TYPE [help-program] FOR HELP ON PROGRAMMING MESSAGES

2.  TYPE [help-transmit] FOR HELP ON SENDING MESSAGES

3.  TYPE [help-setup] FOR HELP ON CONFIGURING YOUR MFJ-493

4.  TYPE [help-list] FOR LIST OF ALL COMMANDS

[help-list]

HELP-LIST INDEX FOR MFJ-493 MEMORY KEYER

[help]           LISTS GENERAL TOPICS

[help-program]   LISTS MEMORY STORING INSTRUCTIONS

[help-transmit]  LISTS TRANSMITTING INSTRUCTIONS

[help-setup]     LISTS KEYER SETUP INSTRUCTIONS

[help-list]      LISTS ALL COMMANDS

[start#]         STARTS KEYER MESSAGE NUMBER # STORAGE ROUTINE

[stop]           ENDS KEYER MESSAGE STORAGE ROUTINE

[{#}]            MARKS FILE FOR ASCII UPLOAD TO MEMORY

[send#]          SENDS MESSAGE NUMBER #

[show#]          DISPLAYS MESSAGE NUMBER # CONTENTS

[co]             STARTS KEYER COMMAND MODE

Among other commands.  There are also commands for printing out the contents of the memories.
So the keyer has a sort of built-in manual if you connect it to a terminal.  Very full featured at used prices.

Using a terminal to the keyer via the serial port also displays everything you send with your key as well as allowing keyboard (terminal) input to the memories or allowing you to send code by typing in the terminal emulator.

Lastly regarding commands.. a useful command to know that's not on the front panel, is that you can reset the 493 to factory settings by holding the menu button down while turning it on.

Cool features not seen in other memory keyers

Two functions FCC Exam Practice and QSO Simulator are lots of fun.  The FCC Exam practice sends a standard FCC CW exam from back when code was required for license upgrades.  It varies up the messages but sends the standard elements required back then.  Good for practice.

But the super-cool feature is "QSO Simulator". This mode performs an interactive QSO with you.

Are band conditions getting you down?  No one answers your calls?  Have a QSO with your keyer!

I'll leave the video to do most of the explaining but basically, the keyer will listen to you send CQ and answer your call and then exchange information with you answering after the turn around.  You're expected to get the call it SENDS you correct or it won't answer you back.  If you send poor CW it makes raspberry sounds at you.  It's just a lot of fun to play around with and copy.

MFJ-493 "QSO Simulator" demonstration

Nits

A couple features that are completely useless are the "hand key" mode and the "semi-automatic-mode".   Once the hand-key mode is enabled you can use either paddle as a straight key but it is very unresponsive at anything over 5-10 wpm.  So keep your straight key wired into the output of this keyer.  Similarly the "semi-automatic" mode is supposed to simulate a bug, where the DITS are sent automatically but the DAHS are manual.  Well it's even worse than the hand-key mode, don't bother as it's for entertainment purposes only.

Another problem with this keyer is related to the weighting commands 'C' and 'W'.  If you have either of them set to a value other than zero you cannot accurately record a message into memory using the paddles.

I'd hoped to be able to run both my paddle and bug into the input of this keyer and switch it to hand mode when I wanted to use the bug and use it as a bug "de-scratcher" but it doesn't buffer the bug input and in hand key mode misses about a third of the DITS sent by a bug so no joy there.  I'll just keep using my old Ham-Keyer as my bug de-scratcher.

MFJ-493 Manual

Many thanks to Paul/N6MGN for sending me a copy of the manual and schematic for this keyer so I could share them.

View manual
Download manual

View Schematic
Download Schematic

So many connections

Adding this additional keyer finally made me break down and build a connection box for all my keys and rigs.  I have 4-5 CW keys on my desk at any given time and 3-4 radios.  Each of the two external keyers have female RCA jacks for output.  The Ham Keyer uses 2 independent 1/4" inputs for straight key and paddle while the MFJ-493 uses a 1/8" stereo plug for the paddle.  The Ham Keyer expects the DIT to be the tip of the plug and the MFJ (by default) expects the DIT to be the ring of the plug.

Arrrgh!

To top it off, each of my primary 3 radios expect different wiring from an external keyer.  

• The Elecraft KX3 needs a 1/8" stereo plug with the ring terminal un-grounded
• The TenTec Eagle needs a 1/8" stereo plug with the ring terminal grounded or a mono 1/8"
• My TenTec Century/21 needs a 1/4" mono plug (my rig is modified, I believe a stock C21 needs a male RCA

So I took a project box drilled it for 5 phono jacks wired in various configurations for each of the rigs and keyer inputs.  I still can't leave the KX3 key plugged in when not in use because when that radio is turned off it presents a high impedance on the plug and makes the C21 think the key is down...  (nothing is ever simple) but now I don't have a bunch of 1/4" to 1/8" and stereo to mono plug connectors chained together like a box-cars on a train.

Video review

This video review demonstrates a few of the features and contains the same QSO in the video above at the end...

Summary

The MFJ-493 is a feature rich yet somewhat flawed keyer.  For the price I think it's a good buy but don't expect some of the more esoteric functions to work up to your expectations.

That's all for now

So lower your power and raise your expectations... and send your call a couple dozen times using a memory keyer

72/73

Richard AA4OO

http://hamradioqrp.com