Friday, February 19, 2016

1 Watt and a Wire... in the Attic

You can't always get what you want, but you try sometimes...

Recently I've dialed my normal 5 watts down to 1watt (one watt, singular) for all my contacts.  To throw some water on the fire I've decided to use my attic antenna which weaves all around my metal ductwork and electrical wiring.   Mostly this was to prove a point to myself but it may be enlightening to deed restricted hams that they can use a qrp radio and an attic antenna successfully.

Key lineup... Palm Single (paddle), Vibroplex Bug (circa 1970s), Kent Hand key

It only seems pointless until you try

Calling CQ with 1w QRPp into a poor attic antenna isn't as pointless as it would seem.  I didn't have to wait long when calling CQ before I got an answer most of the time.  

Now am I going to bust a pileup with 1 watt ?  Possibly not but I think that my assumptions about both how much power I need and how big an antenna I need are usually out of proportion with reality.

1 mighty watt

My assumptions are often incorrect

I made QSOs on 30m, 20m, 17m and 10m this morning all at 1 watt.  The solar conditions report was not really fantastic, especially for 10m.  Yet 1 watt through the attic antenna bagged the only DX I heard on 10m.  I had a couple of other multiple exchange contacts on 20m, 17m and one good old fashioned 25 minute long ragchew on 30m where I received a 599 report for my one watt from Bob (NR8M) in Ohio.  Admittedly, Bob was booming in and we had good propagation to each other.

http://www.hamqsl.com/solar.html

Video

The recording below was number 4 or 5 this morning.  I wanted to post this one because I was working another QRP station in Arkansas (K5EDM) and we did NOT have great propagation to each other.  He was running 5w while I was running 1w so it was QRP to QRPp.  In the video you can see that I'm using some of the KX3's tricks to pull the signal up because there was a lot of QSB and noise (note the GEOMAGNETIC FIELD UNSETTLED in the solar report).  

I had the volume maxed and was using the RF gain control mostly.  I eventually had to turn on the preamp which really washed me in noise but I dropped the RF gain more and eventually switched in the APF (audio peaking filter) which performed magic on this contact.  Often I find that APF doesn't help but this time it made a big difference.


That's all for now

So lower your power and raise your expectations

72/73
Richard N4PBQ

6 comments:

  1. Good evening Richard, at my old townhouse I had a fan dipole in my attic and it worked great! I was making QRPp contacts and one contact that was very memorable was into France with only 20mW, that worked out to 181,958 miles per watt. At the time I was using the K3 with an attenuator. I found I could be my best miles per watt contacts during contests as the op's were really listening for calls.
    73, Mike

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    1. Mike, that's amazing stuff. I'm still learning about the realities of how sensitive our receivers are but the notion that so little power can be transmitted in so many directions and still be reflected by the ionosphere with enough energy to be pulled out by a receiver amongst all the other noise just blows my puny mind.

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  2. Hello Richard. thank's to enthousiasm us with this kind of post... no reason now to stay away from the cw paddle !
    Great...
    F8APV

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    1. Absolutely. CW is your low power friend. No decoding software required (except the wetware between your ears).

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  3. Great video Richard -- convinced me I've been ignoring APF on my KX3 for too long. 73, Bob - W2TAC

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    1. Good to hear Bob. APF on the KX3 is really hit or miss for me. According to Elecraft's operating notes it's effectiveness is highly dependent on properly zero-beating the station but some other conditions seem to play in as to whether it lifts the signal out or just makes it indistinct and fuzzy.

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