Re: DATONG FL3 - Anyone got a circuit?

Nick B. wrote:
Steve wrote:

As a matter of company policy Datong did not and would not provide circuits for their equipment except to their agents.

I had a fault with a bit of their equipment and Mr D.A.Tong (G8???) was most unhelpful, insisting that I would have to send it back for a chargeable repair. I told him exactly what I thought of his attitude and never purchased anything else by Datong.

As the equipment was fairly cheap anyhow, I delved into it sans circuit and got it working again for the cost of a J310 fet.

Thanks to Nick B's website, I now have the full documentation for that PC1 up converter after 20 odd years! Thanks Nick.

There's a story behind that. I thought the PC1 with it's stangely named "parametric" mixer might be suitable to use to provide a base for a 2m->HF transverter. I rang Datong and told them I would only buy one if they were prepared to supply me with the circuit details, much to my suprise they obliged and sent me the service manual. It did work as a low-level TX mixer with a few milliwatts at 144, but due to being a hard up student at the time I soon sold the PC1 to concentrate on other things that students do. Now if anyone has one they no longer have a use for...

You must have got him on a good day ;-) I did also wonder about the transverter aspect at the time of purchase but never followed the idea up.

Back to the FL3 - the observant amongst you will have noticed that this manual is actually for the FL2. The FL3 was basically the FL2 with an additional auto notch filter board piggy backed on top of the main PCB.
The FL2/FL3 are not rocket science by todays standards as (IIRC) they use the ubiquitious MF10 ICs to do the filtering and the data sheets are readily available. I did a couple of mods to improve mine - replaced the 3.5mm jack socket used to power it with a 2.1mm coaxial power connector (the original is notorious for shorting out the PSU). I also replaced the mono headphone socket with a stereo one. I can also see the switch bank being a source of problems if it's had heavy use.

Yes, much later, I came across a FL3 at a junk sale for 50p. The switches were knackered beyond cleaning so it lives somewhere deep inside the junk shed.

Any other Datong manuals anybody? I can scan and PDF so if anyone would like to contribute I'm all ears. I get asked regularly for manuals for the doppler DF system.

Maybe there is someone reading this that was privy to Datong's policy and could provide copies of service sheets. Good luck.

Best wishes