The radio doesn't have any AGC, So when receiving a strong signal your ears get blown clean off, I got round this by building a small circuit that uses an LDR (Light dependant resistor) The incoming audio is rectified and used to power an LED, The LED Shines onto the LDR lowering the resistance which in turn lowers the resistance across the volume potentiometer lowering the volume. The stronger the signal the brighter the LED shines, Details of the circuit and schematics are available online.
Next thing was to swap out the bandpass relays for better quality ones, Harmonics can leak across the stock relays causing harmonics to be transmitted, I used Axicom Relays., I Still need to swap out a few inductors to reduce spurs.
When first built the radio has virtually no RX Audio, I added an LM386 Audio amp but even that wasn't enough to boost the volume, I had to build a small preamp ahead of the LM386 To get the volume up to a decent level, After boosting the volume i then got blasted with feedback on TX Which i got round by adding a relay to take the speaker out of circuit during TX..The radio was designed to be listened to in a quiet room with headphones at full volume, No idea why.
The TX Audio wasn't much better, You have to go into the menu and adjust the BFO To around 11.996.6Khz As standard it's set to 11.995.0 Khz Which results in very thin and tinny audio and isn't enough to drive the radio on SSB, Even after adjustment i still wasn't getting enough drive to be heard so i homebrewed an amplified mic, Now i get plenty of audio. Output power is around 10 watts on the lower HF Bands and falls off as you go higher in frequency to around 2 - 3 watts on 10m.
So with about a fiver spent on parts and a bit of time invested in it i now have a usable HF Rig that in total cost me around £100, Which these days is the price of a NOS Fidelity 1000

That's about it, Hope the above info is useful to somebody who has an early version of this radio, There's plenty more information available online. Any questions just ask



