[Johnson] Done For Tonight & for awhile

Evan Rolek via Johnson johnson at mailman.qth.net
Thu Jul 2 11:56:18 EDT 2015


VFO coupler failure manifests itself in several possible ways.  Lack of VFO frequency change, sticky operation, "grinding" sound when rotating the VFO knob, etc.



The only way I could envision the coupler causing "tube flashing" is if the coupler broke and prevented frequency change, and then one switched bands, "moved" the VFO frequency in-band when in fact the frequency wasn't actually changed, and then an attempt to tune up in a severely out of resonance condition causing excessive peak voltages in the output network.  



73,




Evan, K9SQG




-----Original Message-----
From: richard <ramnaz at peoplepc.com>
To: johnson Valiant Help <Johnson at mailman.qth.net>
Sent: Thu, Jul 2, 2015 11:35 am
Subject: Re: [Johnson] Done For Tonight & for awhile


Hello Roger.
Can't thank you enough for the reply.
If my problem is with the
Coupler how would I know as I have moved the transmitter around a lot on it's
side many times and then back sitting right side up .. I do have a new coupler
coming as I saw on e-bay a guy was making them and he talked about how they
break easy so I bought one...Is there a test to check the coupler and would that
cause the tubes to do as they are. I will try to see how to get to it as I can
take the side panel off the VFO Box & Look and then I will get back to you with
what I find but I am waiting for the new one to come..
Thanks Again Roger.
 
Richard

..................  

-----Original Message-----
>From: Rodger
Singley <WQ9E at btsnetworks.net>
>Sent: Jul 2, 2015 5:53 AM
>To:
ramnaz at peoplepc.com, Johnson at mailman.qth.net
>Subject: re: [Johnson] Done For
Tonight & for awhile
>
>Richard,
>
>The Valiant/SX-101 is a nice vintage
setup and it is what I used as a novice when I got my license in 1975 and
recreating this setup in 1994 is what gave me my start in collecting and
restoring vintage gear. I am currently traveling and I just saw your list
postings.  When I return home I will send you a short document of hints I have
put together for the Valiant, I own 2 Valiant transmitters and a Valiant II  and
have repaired several for friends; I also own most of the other vintage models
from Johnson so I have spent a fair amount of time inside them :)  But one
caution before you go further is there is an insulating coupler used in the VFO
drive which is easily damaged and this usually happens when the Valiant is
turned upside down (with the case off) and the front panel flexes which will
break the coupler.  It fortunately can be repaired fairly easily but it is
unique with different input and output shaft sizes so it is best not to break it
in the first place.  The safe
 st approach is to loosen the set screws in this
coupler before flipping the transmitter over, this allows it to slide on its
shaft rather than trying to hold the panel in place.
>
>I am reading email and
keeping up with the online class I am teaching via a little Asus transformer PC
which is very portable but not great for reading a lot of text so I haven't
closely read all of the postings but if you aren't sure the bias filter
capacitors have been replaced these should be done immediately.  Bias supply
issues will cause a number of faults and some can be very damaging to other
components.  If replacing bias filter capacitors be careful with capacitor
polarity since the bias supply capacitors are installed with the positive
terminal connected to ground-opposite of the more common negative to ground
orientation.
>
>More to follow along with an email attachment of Valiant
repair and operational tips once I return home to IL shortly.  I am currently in
the soggy Smoky Mountains which isn't great for hiking and 12 miles away there
is a big evacuation because of a CSX train derailment with toxic gas leaking. 
Apparently CSX couldn't wait until the 4th to start their
explosions.
>
>Rodger WQ9E
>
>-------- Original Message --------
>> From:
richard <ramnaz at peoplepc.com>
>> Sent: Thursday, July 02, 2015 4:39 AM
>> To:
Johnson at mailman.qth.net
>> Subject: [Johnson] Done For Tonight & for awhile
>>

>> Well as I said in my last note I was going to check the Bias & then check
it out on 40 meters and so I tuned up my antenna for 40 got the Valiant tuned up
and was doing some 123s and  1 of the 3--6146 started to get yellow / green and
so I shut it off and will wait for the man I bought it from to return from his
trip and then let him look at it and I wonder if anyone looked him up on QRZ his
call is NE7X Tom and he has a nice big set up he built. Well anyway I will call
it a night or morning as it is 2:30 am and there is nothing I can do with the
Transmitter doing as it is.
>> Maybe I will be back sometime with other
questions who knows..
>>      73
>>   Richard--- AKA--- KB7FDF--- FDF= Far
Distant Friend Just what all Hams Are..
>> 
>> Richard Morris
>>
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>
>
>


Richard
Morris
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