[AMRadio] DX-100B, output falls off gradually

[ne1s at securespeed.us]

> Hi rick,
>
> Also check to see if you have the mode switch in AM or CW.
> Only in the AM position does the plate switch ground/open the cathode
> circuits. In the CW position the cathodes are connected directly to the CW
> key jack which has shorting contacts when the key is unplugged.
>
> So if you have the mode switch in CW and the key unplugged, then the
> cathodes of the VFO and buffer are always grounded.
>
> 73
> Gary  K4FMX
>
>> At 09:01 PM 11/19/2011, Gary Schafer wrote:
>>
>>  >>>>>
>> >Check to see if there is a jumper wire on the accessory (8 pin socket)
>> >on the back plugged into pin 1 to ground.
>> <<<<<
>>
>> Good evening, Gary.
>>
>> There isn't a jumper, but there is continuity between pin 1 and
>> ground regardless of the position of the Plate switch.  I did check
>> the schematic and pin 1 is connected, through a choke, to the hot end
>> of the side of the Plate switch that connects to the Phone/CW switch
>> and thence to the cathodes of the VFO and buffer tubes.  So, that
>> side of the Plate switch (and, the cathodes of the VFO and buffer
>> tubes) are always grounded whether the Plate switch is on or not.
>>
-SNIP-
>>
>> Thanks for the pointer, looks like you were spot on...
>>
>> Rick WA1RKT

Non of my business really, but kudos to Gary for carefully reading Rick's
original post for help and providing thorough, specific, and precise
information that appears to have nailed the cause of the problem. Oh, and
Rick's post was very clear too, which helps matters. Too often we
half-read a message, and rush to reply with information that is off-track,
creating unnecessary confusion and clutter - been guilty of it myself.

Anyway, good job, guys.

73,
-Larry/NE1S