Archive for the ‘qrp’ Category
VK3YE homebrew 7MHz SSB transceiver
June 9th, 2015 | 
Author: Steve G1KQH (font, or is it fount (?) of all knowledge) sent me this link of the homebrew 7MHz SSB transceiver by VK3YE:
New Homebrew 7MHz QRP rig from VK3YE
How simple?
Some years ago I attempted to see how few components were needed to communicate on 10m. The Lesser Chirpy was the best I could manage. This was a derivative of The Chirpy, which worked, but had far too much chirp!
Looking at the circuit I see I could save 1 component by replacing C1 and C2 by preset C’s and shorting out C3. This would allow the TX-RX offset to be set. If one was made a variable rather than a preset the RX-TX offset could be adjustable.
Since being ill I have not tried the rig. A limitation was the limited RX sensitivity, meaning only stronger stations would be workable. However, the rig does work and is very simple. Another possibility is to switch to an external RX but allow the internal RX to be used when signals are strong enough. The TX power is certainly enough to span the Atlantic and work all over Europe.
The secret to low chirp on 10m is the use of FSK rather than CW. Essentially the TX changes frequency rather than go from RX to TX every time. This means full break-in is not possible in such a simple circuit. Can you do better? If so, I’d love to see the schematic please. I make no great claims for my circuit, which is an amalgam of ideas. Pure fun!
Inexpensive Kit From China
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| courtesy: http://www.banggood.com/ |
A recent posting to the GQRP Yahoo Group brought my attention to another inexpensive offering from China. This time it's Bangood's complete "Pixie" type 40m QRP transceiver for the incredible sum of $4.16 (U.S.)! The price includes all components, a nicely silk-screened PCB and free shipping. One really wonders how it is possible to make any profit with such an offering but it obviously is. However, all may not be what it seems. One purchaser, IK1ZYW (Paolo) who built the kit, described his findings in a recent blog posting of his building experience.
In spite of the problems noted above (with some now corrected), the kit still seems a bargain, if one takes the necessary care with construction.
Playing with QRP can often provide ham radio's best "fun for the money" as DX- capable transmitters can often be built for just a few dollars. I vividly recall the fun I had one winter while pursuing the first-ever Tuna Tin W.A.S. endeavour on 7040kHz.
I made many new friends on 7040 that winter and every weekend many of them would listen-in or call to see how my progress was going. The highlight of the adventure was late one Saturday night when I had three New England stations all answer the same CQ ... what amazing fun for a handful of parts at less than $10 ... not including the cost of a can of Tuna!
The little Pixie kit offered above has a power level fully capable of W.A.S. on 40m and with the decrease in solar conditions, 40m will just keep improving. If you purchase and build one of these kits, please let us know how your experience went. The 'interesting' construction notes may be found here.
My QRP signal is spotted in Europe!
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| P3 on 20m showing some signals |
Rockmite
As I’m moving towards CW as an operating mode I took the plunge and bought a Rockmite kit from Kanga. Lets just say its not working quite as I had anticipated. This time I was very careful to look at the various instructions. Lid everything out and then checked every component as I assembled it.
Next time I’ll throw these things together in the usual manner. I might have a bit more success. Power on and I get little in the way of audio, a gentle hiss but not much else. So troubleshooting has to begin. Fortunately there is quite a bit of help for this but to be honest I’m not holding out much hope as I did such a thorough job of checking the first time round. Must be a faulty (insert component here) 
All good fun and not as if the world will end if I have to spend some time on it.
ARRL CW Contest done QRP style
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| Oliver is asking……"Ahhhh dinner!!! |
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| The rig setup |
Score rundown is as follows
Contacts DXCC's Points
81 39 9360
The equipment used was the Elecraft K3 with 500,400 and 250 inrad filters, the Elecraft P3, Begali Contour Key and the Flex control external VFO knob and last but not least the MFJ 1788 Magnetic loop antenna. The software used were N1MM+ contest software, N4PY rig control software and MRP40 CW code reader for the chain saw speed code. I never had Murphy pay me any visits during
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| The contest software |
Monday brings two dx contacts
late afternoon it was time to go out with Julie who had a photography assignment that involved us going downtown (Toronto) for some shots she needed to get. It sure was cold out but soon we would be back to our warm home and just a little more radio time as she edited some photos. This time on 20m I heard HC5AI calling CQ from Ecuador and after some going back and forth he got my call and the contact was made.
