I have started a new thread as the previous "TS480 RFI - more information" has become rather long.
If anyone has TS480 RFI problems - please see the previous thread before doing anything else and resolve any confusion with the ground wires, and deal with that first.
After doing the ground wire strapping changes I have been able to run 100w barefoot on 80m thru 10m with no problem including the use of the speech processor.
Last week I re-connected the SPE Expert amp. Using it locally (mic plugged direct into head unit) everything worked perfectly. However, trying again to use it today remotely with someone listening a few miles away from the remote site, there are serious problems.
1) Running the same 100w barefoot with the amp in circuit (but in standby), I am getting a regular pulsing about 2 pulses per second when pressing the PTT but not speaking, I can see around 3w being registered on the amp with occasional 20w peaks. when speaking, the pulsing is still there underneath the audio. This is the same on both the 80/40 dipole and the separate 20m dipole. This is without the speech processor, if I enable the processor it is totally un-usable.
2) On 20m I can run 400w CW without problem
3) On 40m if I send very slow dashes, the received signal a few miles away is varying by over 10db.
I believe someone else reported that an Alpha amp worked perfectly well, but when swapped for the SPE amp, he had a lot of problems. I would like to know what actions were taken and whether a cure was ever found?
I am suspecting the RS232 lead. Does anyone have experience of RS232 isolators and whether one might help?
73,
Dave, G3UEG
