02-08-2017, 07:29 AM
(31-07-2017, 11:20 PM)VK3ALB Wrote: Hi Peter,Hi Lou
Once you've found the VFO and/or BFO you should be able to loose couple a signal from a TX (a wire hanging near a dummy load) to the antenna input then search for a signal with your RX at the output of the 1st NE602. Once you have that repeat the process for the remaining stages.
Yes it would be nice to use a sig gen and a 'scope to see what is going on. Is your colleague or a local ham club in a position to assist you?
Thanks advice. I can't listen for the BFO and VFO on my receiver, as it doesn't cover the frequencies of the oscillators, but according to my RF probe they are oscillating ok. I connected my main tx/rx to dummy load, wrapped wire around it and connected to ant input of the rx but could not find the signal. The IC's all seem to be ok, so my next step is to check the toroid link at the ant input by linking the picked up signal from main tx via the dummy load to the other side of the toroid, and see if another rx will pick up signal from there.
I posted this thread on this site as the rx is an Aussie design, so thought there might be someone there who has built the rig, although it was published some years ago. Some of the components were difficult to source, like polystyrene capacitors, and the beehive trimmer. I guess they could have been substituted with something else, but wanted it to be true to Drew's original design.
It looks to be a good superhet receiver. I built the 80/40 Tx that goes with it, and it works fine. I wondered if Drew himself contributed to this site, and might give some advice. Someone suggested I contacted him myself. I have his address, but no email so I might drop him a line. Regarding colleagues, there are a couple of guys at the radio club that might help, as they have alll the test equipment and more knowledge of electronics than me, but they are busy with other things, and they are into digital stuff, Arduino etc, but I'll give it a shot. The G-QRP Club that publish the books with Drew's designs in do a service fixing failed homebrew rigs, but I will have to pay. Pride stops me going there, determined to sort it out myself
Anyway, thanks for all your help, I'll get there in the end.
Hope for a QSO with a VK sometime, but with the way propagation is at the moment not much chance!
Right, back to the drawing board.
73's
Peter