[Boatanchors] Globe Electronics V-10 VFO

[Rob Atkinson]

On the 755 the B+  is supposed to be 170 and 150 v.  There are a pair
of resistors that do the v. dividing and smoothing; no filter choke.
It is probably safe to assume the VFO draws around 100 ma, maybe 80
ma.   When I pulled the selenium rectifier and put in a silicon diode,
the B+ was up around 220 v.  That may be okay--I don't know but I
thought perhaps sticking with the original design voltage would have
something to do with stability.  Measure your B+ with the diode and
depending on how high it is, try adding a series resistor of 300 to
400 ohms.  SRs have a pretty high Vd, much more than silicon.  That is
what needs to be compensated for.  If you go with 400 ohms and the
current is 100 ma you'll have to dissipate 4 watts.  I think went with
a w.w. 5 or 10 watt job or paralleled some 2 watt carbons but I got
the power dissipation up to at least 5 watts.

since you have a VC10?  YMMV as I don't know how much its design
varies from the 755.

73

Rob
K5UJ

On Sat, Sep 1, 2012 at 12:54 PM, Glen Zook <gzook at yahoo.com> wrote:
> Probably, I had a wirewound 5-watt so I used that!
>
> Glen, K9STH
>
>
> Website:  http://k9sth.com
>
>
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>>________________________________
>> From: Charles Ring <w3nu at roadrunner.com>
>>
>>
>>
>>When replacing these small selenium rectifiers with 1N4007's, what is the proper series resistor (or additional 1N4007's) to add? Thinking of both the 755 and V-10.
>>
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