I did clean the contacts as part of the troubleshooting process and used an
ohmmeter to make sure it was switching. Figured there was a chance I
banged into it while working but don't think I did. While testing, key
down, I gently pushed and tapped on it with a stick of G10 which is what
prompted me to clean the contacts. I was watching the antenna analyzer
draw out the curve on the input side while doing this and could see ~ 2.0:1
SWR jumping up to infinity and back on 80. I can't under any condition get
anything but infinite SWR on any other band setting. Very strange. I'll
get the deck pulled so I can get into the compartment under the tube
sockets and go from there. I wonder if somehow the two parts of the band
select switch got out of sync. I really can't see it from above for any
kind of testing so I'll have to pull the deck off the rest of the chassis.
Thank you,
Bob
On Tue, Nov 21, 2017 at 9:38 AM, Victor Rosenthal 4X6GP <k2vco.vic@gmail.com
> wrote:
> Make sure the contacts on the t/r relay are clean and that it is pulling
> in properly.
>
> 73,
> Victor, 4X6GP
> Rehovot, Israel
> Formerly K2VCO
> http://www.qsl.net/k2vco/
> On 21 Nov 2017 18:32, Bob Darlington wrote:
>
>> Confirmed, the front panel does use Sylvania 1815 bulbs and the LED
>> replacements from Amazon worked just fine. I replaced the little GE 330
>> bulb in the power switch with an LED equivalent as well. Turns out the
>> 1815 bulb is listed in the parts list and I just missed it the first time
>> around.
>>
>> The knobs do use Bristol set screws. Never heard of this standard before
>> but now I own a small set of them for future work.
>>
>> Got my first signal report on 40 meters. The guy said I just about
>> knocked
>> is radio off the bench. Clean and crisp and loud.
>>
>> And then I went back into the amp last night to add in a pair of diodes on
>> each meter and to take some pictures. I managed to unstick the sticky
>> "multi" meter on the left. I pulled the tubes and cleaned the chimneys
>> and
>> reassembled after doing a little cleaning with a moistened paper towel.
>> The date code on the tubes is 7813. 13th week of 1978?
>>
>> And after putting it back together I get no output. I did for a short
>> while and I'm not at all sure why I'm not getting output now. Only on 80
>> meters does the thing make the familiar hum and show grid and plate
>> current. And that's intermittent at best. I have to slam it into
>> position
>> for it to work. SWR meter on my K3S is moving around a bit. Knocking my
>> knuckles on the chassis gets it to stop working and I have to give it a
>> good slam get it to produce power again. Every other band shows high SWR.
>> Sigh. Time to pull it apart and get it on the bench and rig up a signal
>> source and scope and troubleshoot. The SWR curve on 80 while it is
>> working
>> looks to be quite different than it did before I broke it (I used an AA-55
>> to get a baseline curve and stored them for later comparison). It feels
>> like there is no input RF connection out to the filaments and yet I do get
>> output on one band (sometimes).
>>
>> -Bob
>> N3XKB
>>
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