HFU HF Underground

Technical Topics => Equipment => Topic started by: mhmod on September 19, 2019, 2149 UTC

Title: TECSUN PL-660 FM & SW Issue
Post by: mhmod on September 19, 2019, 2149 UTC
Hello everybody
My PL-660 have two issues  :-[
1- The FM has no reception after 93.70Mhz but it works fine from 87Mhz to 93.70Mhz. :'(
2- The SW has no reception at all, just noise without any stations. :'(
Is there is anybody knows what I have to do to solve it ?
I know the basics of electronics and soldering and I have the necessary tools but I'm not expert enough to diagnosis the problem.
Title: Re: TECSUN PL-660 FM & SW Issue
Post by: Looking-Glass on September 22, 2019, 0012 UTC
I have a Tecsun S-2000 and like you the FM band is shot, strange noise creeps up the FM band and thus no reception from the bottom segment to where the noise is, gradually creeps higher as the months pass.

Aviation VHF band is unaffected.

Shortwave is working fine, although the BFO is all over the place for CW and SSB reception, I find that by using the "reset" function with the BFO set to noon position prior to "reset" usually resolves the problem.

So, in essence, try the "reset" function?

Failing that it looks like a component failing issue, if it's still under warranty I would be pursuing redress via that medium, if out of warranty then it might pay to open it up and run the meter over some of the components as per the schematic and trace it that way... 8)

Cheap Chinese junk box radio's so cannot expect much I guess... ;D
Title: Re: TECSUN PL-660 FM & SW Issue
Post by: ThaDood on September 22, 2019, 0244 UTC
Believe it, or leave it, I've actually solved problems by resolding with actual 60/40 solder on new gear. The reason??? That damned LoHS, (Lead Free.), solder just sucks! So, ya might try looking for what looks like a cold solder joint. (That maybe many, as well as those leftover solder hairs that are conductive.) Another thing to look for? Under voltage electrolytic capacitors. Last month, I bought a Uniden Bearcat 980SSB CB rig on sale. But, I did take care of one big issue that Uniden still has, under voltage electrolytic CAP's. Sure enough, I've found, and swapped out, three of them. At least, these could be places to start at.