[Heath] [Heathkit] HW100 loss of signal

[Eddy Swynar]

On 2012-09-14, at 3:45 PM, Dick KF4NS wrote:

> Just when I thought I  had all the problems solved and put the rig back in service, this ruins my day.
> 
> I had the rig on 20M with great signals coming in, all is well for about an hour and suddenly the S-meter 
> drops to zero and audio goes dead. I just touched the band switch which had been completely gone over 
> during maintenance, and full service was again back. All contacts were working fine and tested for 
> continuity. All bands were performing fine. I let it go and a while later it did it again. This time I 
> switched from USB to LSB and it perked right up and both sidebands were fine. I decided to try 40M and 
> 15M. They never failed. Went back to 20M and guess what? It did it again !!
> 
> Some things are pretty self apparent and a bit of digging can get things going again. I just cannot 
> rationalize this MODE switch BAND switch thing only on 20M. Scanning over the schematic I could not begin 
> to make the connection.  What seems so very odd is the loss of RF input shown on the S-meter and total 
> loss of audio at the same time.
> 
> Scratch your heads, rattle your brains and throw some darts at the schematic and please let me know what 
> makes the bell ring.
> 


Hi Dick,

I don't know if this will be of much help in your situation, but about 20 years ago I had a Heath SB-102 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 Fox-Tango CW filter. That rascal won 40 CW honours for several years as the biggest points accumulator in our local club for many a FD!

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.

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!!!

I wonder if you might be experiencing a bad joint there as well, one that's somehow unique to just 20-meters...?

~73~ de Eddy VE3CUI - VE3XZ

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