Chirpy Viking Ranger

[Freeberg, Scott (STP)]

Rod,

I just finshed troubleshooting my Valiant (with the same VFO as the
Ranger) for a problem that may apply to you.

In my case, the transmitter started blowing 1.5 amp low voltage fuses.
There is an 18 K current limit resistor inside the vfo case between the
OA2 and the +300 volt power supply.  I have been told by several folks
on this list that the resistor power rating is underspecified and it has
a tendency to run way hot and eventually burn up.  In my case, it burnt
up and ruptured, changing the resistance value from 18K to 150 ohms.
This caused the OA2 to burn up trying to regulate the voltage under high
current conditions.  When the OA2 burned up, the 6AU6 was damaged by
having 300 volts applied to the screen.    Then of course the 5V4 300
volt rectifier tube burned out.

It working very well now and glad to have it back.  I replaced the 18K
with two 36K 6 watt parts in parallel and mounted them to a new terminal
strip under neath the VFO.  The wire from the OA2 and the terminal strip
fit nicely through the grommet right there inside the vfo.  I did not
want to have to work inside that VFO cabinet either.

Visually inspect the resistor and measure that 18K value.

Oh yes,  my 6AU6 checked out good on my borrowed tube tester but it was
bad anyway.  Replaced it and that was the end of it.

73,

Scott WA9WFA Saint Paul Minn


> -----Original Message-----
> From: w5hvv at aeneas.net [SMTP:w5hvv at aeneas.net]
> Sent: Wednesday, February 04, 1998 8:20 PM
> To:   glowbugs at www.atl.org; BOATANCHORS at LISTSERV.TEMPE.GOV
> Subject:      Chirpy Viking Ranger
>
> I am in the process of attempting to repair a Viking Ranger for a
> friend of mine that has entrusted it to me for that purpose (talk
> about mis-guided trust!).  I have used kerosene to clean up the
> chassis and so forth and it looks like a million dollars now.....
> but the purpose he gave it to me was to get it to quite chirping and
> migrating up the frequency while transmitting.  I have removed the
> side panel from the VFO unit and the OA2 is glowing all the time;
> just a tad less when the key is down, so I discount it as a problem.
> I don't have (at the moment) a spare 6AU6 to try but can get one from
> my supply tomorrow or the next day.
>
> My question is: is there anyone out there that has encountered a
> similar problem and is there something easy to do that will correct
> it?  I have an absolute horror of trying to remove the entire VFO so
> that I may get to any temperature sensitive capacitors or the tuning
> capacitor.  It appears that I would have to take off the front panel.
> I am not into that much pain.  Is there anything else that is a
> viable alternative?  Anyone had to fix a similar problem on their
> Viking Ranger and can tell me where to go to look for the problem?
>
> Thanks,
>
> Rod, N5HV
> w5hvv at aeneas.net
>

--- --- --- --- --- --- --- --- --- --- --- --- --- --
To subscribe: listserv at listserv.tempe.gov
and in body: subscribe BOATANCHORS yourfirstname yourlastname
To unsubscribe:  listserv at listserv.tempe.gov
and in body: signoff BOATANCHORS
Archives for BOATANCHORS: http://www.tempe.gov/archives
--- --- --- --- --- --- --- --- --- --- --- --- --- --