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

Need help with a Ham Christmas QSO card

Too early to plan the Christmas QSO card?

Ok, so it's only January but Christmas is just around the corner and I need help with a verse to go with my 2018 Christmas QSO card.

It starts like this...

We three keys from ham shacks are,
Sending code that travels afar, 

. . .

That's all I got.  Help me out.

Just a bit of silliness

So lower your power and raise your expectations

72/73

Richard, AA4OO

Giant Blizzard! Not really, but my antenna is down

We aren't supposed to get this much snow in central NC

We received a remarkable amount of snow yesterday here in central NC, my antenna iced up and looked very pretty, then the wind picked up and my antenna fell down.  Boo-hiss !

My homebrew OCFD antenna is constructed from donated, surplus, lightweight doorbell type wire attached to a 4:1 current balun in a PVC tube with threaded nuts to hold each end of the dipole on top and a coax connector on the bottom.  An eyelet through the top of the balun suspends it all via some 10 year old dacron rope (dacron rope is amazing stuff), which is attached to the eave at the peak of my roof.

How, pray tell did I get the rope attached to the peak of roof 33 feet up in the air you ask, having no tall ladders or Spiderman abilities? I'm glad you asked... Well, the rope is tied inexpertly, using granny knots, to one side of an S-hook.  I use a cane-pole fishing rod as an extension with a piece of masking tape on the end lightly holding the S-hook. Then I precariously lean out my 3rd story window eight feet under the eave (don't try this at home) and "fish" the S-hook through a loop at the peak of the eave, that was installed there by my nice painter, many years ago.  Once the S-hook is in the loop, I tug on the fishing pole and the masking tape lets loose of the S-hook and the S-hook remains in the loop, holding a few feet of old dacron rope.  QRP-indeed !

This incarnation of the antenna was first installed November 2015.  In that time an ice storm drug it to the ground, and a tropical storm broke the mooring as well.

Amazing stuff, doorbell wire and old dacron rope.

That gleaming line of ice from right to left in the picture below used to be elevated a bit more

Even with my outdoor antenna down, I was able to make a contact on 80m last night using the 68'ish foot long doublet in my attic so wasn't completely incommunicado.  It shouldn't be hard to get the OCFD operational again.  A bit harder will be repairing the blueberry cage that collapsed under the weight of snow on top of the netting.

This antenna is designed to fail gracefully

I wanted to be sure that when the antenna was under stress it would relieve itself at the easiest place to repair.  The rope on the long end of offset dipole runs through a pulley attached, with a zip tie, at the top of a set of sturdy, stacked fiberglass tent poles.  The rope runs through the zip-tie attached pulley to a long, lightweight, spring (the kind used for a small fence gate) along with the pulley provides the strain relief when it's windy. The zip tie holding the pulley at the top of the pole is intentionally the weak link.  When the forces become too much the zip tie breaks and the long, heavy side of the antenna falls across the garden.  It's a simple matter to pull a section of the fiberglass pole loose, attach a new zip tie, and Bob's your uncle.

So when you design your next wire antenna, plan ahead for easy repair.

That's all for now...

So lower your power and raise your power... and antennas after they fall

72/73

Richard AA4OO

Troublesome characters to copy in Morse Code

The trouble with DITS

KX3 Displaying some sent code and a Palm Single paddle in front, magnetically attached to a steel base

As I've learned the code one problem area, early on, was dealing with words that started with characters that were all DITS.  I'm probably not alone in having my puny brain overloaded when I am trying to head copy words that start with DITS.  I would panic because the all-dits character would fly by and I'd get fixated on trying to figure out what that was and miss the rest of the word.

To overcome DIT panic, I started training on the all DIT characters of E, I, S and H

Using https://lcwo.net/  I'd configure it to send only those characters, and practice them alone.  Then I started creating words that began with DIT characters and I'd practice recognizing them.

After two and half years I still get tripped up on occasion but I'm doing much better.  

I also like to practice sending DITS.  The following sentence is fun to practice: "SHE IS 55 ES IS HIS SISTER"

So how do you deal with DIT overload?  

That's all for now.

So lower your power and raise your expectations...

72/73

de Richard AA4OO

http://hamradioqrp.com

https://www.youtube.com/user/4gven

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

Video recording woes

Getting the audio right shouldn't be this hard...

I've spent a considerable amount of time lately creating machine generated Morse code videos for copy practice.

I've created videos of the top 100 Words, 500 Words and today, the top 100 most common words in a QSO, at different speeds.  I'm machine generating rather than keying them by hand because I would make too many mistakes.  I do this through my memory keyer connected to the computer via a terminal application and capture the text being sent along with the audio.

Getting the audio right has been hard. When I record screen captures on my PC it wants the audio to be recorded at 44 kHz but when I transfer that to a Mac to use my video editing software, it expects the audio to be recorded it 48 kHz, and converting the audio in the video just doesn't work well.  I use an H2 USB mic for the recording.  If I set the mic and the PC screen capture software to 48 kHz I get no audio. So I have had to record at 44 kilohertz on the PC. I'm sure there's better screen capture software that could be used on the PC but I haven't been able to find it for free. I guess I'm too cheap.

This has caused my videos to have popping noises in the transferred audio. While I've tried to fix it during the editing process, it still sounds bad to me.

So, you may wonder why haven't I just recorded the videos on a Mac from the beginning rather than using a PC?  Well, I haven't been able to get the OSX terminal application to talk to my 1990's MFJ Super Memory keyer via the serial cable. For some reason my Mac doesn't have a driver for the usb dongle I used to talk to the old memory keyer but my PC does. I searched a bit more and found a non-free terminal application that will let me connect to this serial cable.  Now I connect from the Mac and capture the keyer output.  I'll spend hundreds of dollars on ham gear but ask me to shell out $30 for computer software and I balk.  And after all, I'm a software developer, shame on me.

So, starting today, my new videos should have improved audio and be at a higher resolution than previous videos recorded from the PC.  

These practice Morse code videos seem to be popular with folks, so I hope they're helping people. They're a lot of work but I guess they're worth it.

That's all for now...

So lower your power, and raise your expectations

Richard AA4OO 

http://www.hamradioqrp.com 

No love for CW in ARES / RACES

CW - emergency communication ?

With the recent spate of natural disasters and dire warnings of impending doom, from terrorists and rogue nations alike, it got me to looking into my previous emergency ops participation.  

When I was a newly minted amateur operator about a decade ago, I participated some in traffic nets and obtained FEMA certifications to participate in emergency operations.  At the time I had built my go-kit, consisting of battery powered FM 2m/440 equipment and portable J-poles.  It even had wheels and a pull handle, very spiffy.  But I wasn't much concerned with CW.

With a re-kindled interest in QRP and CW operations, it got me to looking again at participation in emergency ops, and to my surprise there are few states that even list CW as a mode for emergency communication frequencies.

The following table lists the only pre-approved ARES frequencies I can find, designated for CW.  There are 37 states missing from this list... If you live in a state other than those listed below; no CW emcomm for you buddy.

STATE	FREQUENCY kHz	MODE	SECTION DISTRICT	DESCRIPTION
AR	3,570.00	CW		MTN/OZ, KCW Traffic NET
CA	7,111.00	CW	SAC	(UP) NTS/ARES/Traffic/Calling, Daytime
	3,711.00	CW		(UP) Daytime
LA	3,673.00	CW	LA	NET
MI	1,812.00	CW	MI	Alternate Emergency Frequency (Winter/low flux)
	3,563.00	CW		Emergency
	7,068.00	CW		Alternate Emergency Frequency (Summer/high flux)
MN	3,568.00	CW	MN	ARES
MS	3,570.00	CW	MS	MS/AR CW Traffic Net
NE	3,540.00	CW	NE	Primary
NM	3,540.00	CW	NM	Primary
NC	3,573.00	CW	NC	Primary
	3,571.00	CW		Alternate
OH	3,577.00	CW	OH
OR	3,587.00	CW	OR	Daily 1830 and 2200 Oregon Section Net
SD	3,578.00	CW	SD	net during an emergency/drill
WI	3,555.00	CW	WI

Excerpt from http://www.idahoares.info/resources_ares_frequencies.shtml   I looked in a number of ARES/RACES sites listing nationwide frequencies and they appeared to have the same list

Why no love for CW?

I understand that CW is a slow mode of communication and not well represented by the amateur radio masses, but let's face it, CW has more efficiency at getting a signal through in marginal conditions than FM or SSB.  When a disaster strikes and the electrical grid is down for hundreds of miles and gasoline for running generators is short, you won't be operating QRO stations or have power to run computers for digital modes.  Powering a 12v battery with a solar panel may be your only option.

CW's power density is superior to any non-digital mode.  A 5 watt CW signal packs as much punch  as 100 watt SSB and let's not even discuss the inefficiency of FM or AM.  In extended emergency conditions, using CW could mean the difference between getting a message through and not.

Operating CW in Emergencies

So if there were an extended emergency, shouldn't there be some fallback plan for use of low cost, easy to build and store XTAL controlled radios?  Many home-built XTAL controlled CW radios use QRP watering hole frequencies for their center frequency; 3560, 7030 and 14060 kHz.  Why not designate those frequencies using CW as standards for emergency communication?

Maybe CW is sinking so far into obscurity in amateur radio, this sort of thinking doesn't enter the consciousness of those in charge, but I don't think it should.  Maybe CW clubs like FISTS and SKCC could partner with QRP clubs (who tend to be CW focused) to form a homespun group of emergency operators prepared to use CW when all else fails.  It might be fun to organize, and who knows, it could save a life, or reunite separated family members.

That's all for now...

So lower your power and raise your expectations

72/73

Richard, AA4OO

http://hamradioqrp.com