<html><head></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><br><div><div>On 2012-09-14, at 3:45 PM, Dick KF4NS wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"><div>Just when I thought I had all the problems solved and put the rig back in service, this ruins my day.<br><br>I had the rig on 20M with great signals coming in, all is well for about an hour and suddenly the S-meter <br>drops to zero and audio goes dead. I just touched the band switch which had been completely gone over <br>during maintenance, and full service was again back. All contacts were working fine and tested for <br>continuity. All bands were performing fine. I let it go and a while later it did it again. This time I <br>switched from USB to LSB and it perked right up and both sidebands were fine. I decided to try 40M and <br>15M. They never failed. Went back to 20M and guess what? It did it again !!<br><br>Some things are pretty self apparent and a bit of digging can get things going again. I just cannot <br>rationalize this MODE switch BAND switch thing only on 20M. Scanning over the schematic I could not begin <br>to make the connection. What seems so very odd is the loss of RF input shown on the S-meter and total <br>loss of audio at the same time.<br><br>Scratch your heads, rattle your brains and throw some darts at the schematic and please let me know what <br>makes the bell ring.<br><br></div></blockquote><br></div><div><font class="Apple-style-span" size="4"><span class="Apple-style-span" style="font-size: 14px;"><br></span></font></div><div><b><i><font class="Apple-style-span" size="4"><span class="Apple-style-span" style="font-size: 14px;">Hi Dick,</span></font></i></b></div><div><font class="Apple-style-span" size="4"><span class="Apple-style-span" style="font-size: 14px;"><br></span></font></div><div><font class="Apple-style-span" size="4"><span class="Apple-style-span" style="font-size: 14px;">I don't know if this will be of much help in your situation, but about 20 years ago I had a </span></font><i><font class="Apple-style-span" size="4"><span class="Apple-style-span" style="font-size: 14px;">Heath SB-102</span></font></i><font class="Apple-style-span" size="4"><span class="Apple-style-span" style="font-size: 14px;"> that I acquired from an estate sale---I immediately fell in love with it for use as a mainstay 40-meter CW station on Field Day, & "hot rodded" it some with the addition of R.I.T., & a 250-Hz </span></font><i><font class="Apple-style-span" size="4"><span class="Apple-style-span" style="font-size: 14px;">Fox-Tango</span></font></i><font class="Apple-style-span" size="4"><span class="Apple-style-span" style="font-size: 14px;"> CW filter. That rascal won 40 CW honours for several years as the biggest points accumulator in our local club for many a FD!</span></font></div><div><font class="Apple-style-span" size="4"><span class="Apple-style-span" style="font-size: 14px;"><br></span></font></div><div><font class="Apple-style-span" size="4"><span class="Apple-style-span" style="font-size: 14px;">Well, one year, as I was preparing tho fire-up the rig on the last weekend of June, its output was visibly dropping, simultaneous to its sensitivity slowly fading. In a matter of minutes the set was dead---and deaf. I had no idea what was ailing it, but we managed to salvage FD with the use of a back-up rice rocket rig.</span></font></div><div><font class="Apple-style-span" size="4"><span class="Apple-style-span" style="font-size: 14px;"><br></span></font></div><div><font class="Apple-style-span" size="4"><span class="Apple-style-span" style="font-size: 14px;">Well, I must have spent month after month after month going over the thing, trying to trouble-shoot it. Finally I took the ol' "shot gun" approach in absolute frustration, replacing each & every board one by one with parts secured from on-line "donor rigs." Nothing worked. Finally I came to the conclusion that it was time to part the thing out, & rid it---and myself!---of accumulated misery. Well, as it was, the last boards that I parted-out from the '102 were the vertical rectangular ones in the driver portion of the rig---and guess what I discovered...? A bad / cold solder wire connection that was common to all of the bands, & to both receiving and transmitting!!!</span></font></div><div><font class="Apple-style-span" size="4"><span class="Apple-style-span" style="font-size: 14px;"><br></span></font></div><div><font class="Apple-style-span" size="4"><span class="Apple-style-span" style="font-size: 14px;">I wonder if you might be experiencing a bad joint there as well, one that's somehow unique to just 20-meters...?</span></font></div><div><font class="Apple-style-span" size="4"><span class="Apple-style-span" style="font-size: 14px;"><br></span></font></div><div><b><i><font class="Apple-style-span" size="4"><span class="Apple-style-span" style="font-size: 14px;">~73~ de Eddy VE3CUI - VE3XZ</span></font></i></b></div><br></body></html>