The GQ20 Transceiver Project


Notes by Paul, G0UBV

I ordered my GQ-20 when it first appeared in SPRAT, and was one of the lucky (I thought) 100 who got hold of a kit at the introductory price.

The first thing that struck me was the sheer number of components, all bagged up neatly by JAB.

Things started to go wrong shortly after construction commenced. John G3RHP posted a message to G-QRP asking if anyone knew what the value of R56 was supposed to be. We teamed up and built our GQ-20 kits more or less in parallel. The result was the GQ Buglist, now held on this Web page. If you read the buglist, youíll get some idea of the numerous problems we came up against.

Itís hard not to be critical. There were so many errors in the circuit diagram, component values, instructions and even the PCB, that construction eventually became a chore rather than a pleasure. Some of the wiring errors were potentially disastrous. The method of PCB construction is curious, with numerous components having one leg soldered directly to the ground plane on the upper side of the board. Bending the leads of tiny components at right angles, and soldering them into a tightly packed board requires nimble fingers and great patience, neither of which are in good supply at this QTH. The chassis work had not been properly thought out and kitted, and this part of the construction also became a pain.

Does it work? Well, yes - sort of. Read the buglist and youíll see where John and I ended up. The problem is that my GQ-20 feels like it will never be quite right, and will never live up to its promise.

The Rx really needs a pre-amp and OK, this is easily added. But the Tx note is marginal, the VFO pulls on key-down, the note chirps on full QSK and I suspect that the neutralising in the PA is less than fully effective.

I get a lot of satisfaction from operating home-built equipment such as my G4ENA QRP/QSK tcvr as featured in RadCom May 92. Unfortunately, I canít say that about the GQ-20, which has remained unused since I got it working to about 75% of what I felt it should be able to do. Later kit releases had corrections and some changed component values. One day, I might work up the enthusiasm to have another go at it, but for the moment, it remains on the shelf. I discovered recently that Johnís GQ-20 is in a similar situation.

Still considering the GQ-20? Well, I know one builder who is pleased with his.

Remember this is not a beginners project and I reckon the component density puts it towards the extreme edge of what itís practical for most folks to build by hand. Maybe the GQ-40 is a better proposition - my guess is that the GQ is really a 40m rig, and that 20m was added as a bit of an afterthought.

Paul Tuton G0UBV

ptuton@ptuton.demon.co.uk


Many thanks to Paul G0UBV for the above notes and pictures.(G3YCC)


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