[Boatanchors] Jojhnson Viking Model 122 VFO wnted

[Glen Zook]

The WRL 755 and 755A VFOs are excellent.  I got my first 755 in October 1959 when I upgraded from Novice Class to General Class to go with my Globe Chief 90A.  Acquired another one a while back to re-create my original General Class station.  They are very stable and have a built-in power supply.  Also, they, like the Heath VF-1, do cover 160-meters.

However, with a few no wiring changes, the Heath VF-1 VFO can be made very stable.  First, replace the 6AU6 with a 6AH6.  Next, replace the 0A2 screen voltage regulator to an 0B2.  This reduces the screen voltage to 108 VDC instead of 150 VDC.  Finally, run the VFO from a separate power supply supplying 150 VDC regulated.  The 0A2 removed from the screen circuit can be used in this power supply.

The only thing that may be required is to "touch up" the variable capacitors in the calibration because the 6AH6 has a slightly different inter-electrode capacitance than the 6AU6.
 
Glen, K9STH


Website:  http://k9sth.com


________________________________
 From: D C _Mac_ Macdonald <k2gkk at hotmail.com>
To: K5UJ Bob Atkinson <ranchorobbo at gmail.com>; "boatanchors at mailman.qth.net" <boatanchors at mailman.qth.net> 
Sent: Wednesday, March 6, 2013 6:56 PM
Subject: Re: [Boatanchors] Jojhnson Viking Model 122 VFO wnted
 

The WRL Globe 755 I built was VERY stable. 
I used to zero on SSB QSOs and join in with 
my Globe Scout 65 and 755 and most didn't 
even know I was on AM! Every once in awhile, 
a new SSB station would come on to the chat 
and be a bit off freq and then they'd detect 
MY full carrier and tell me I needed to reset 
my carrier balance! That was fun. 

Anyway, that 755 was a big improvement over
its Heathkit VF-1 VFO.