[Amps] Commander VHF-1200 questions

[Don Kessler]

Jeff -- Contact me off-line.  I can probably provide some information 
that might be helpful.

Regarding lineage:  Commander was sold to AN Wireless.  VERY shortly 
thereafter AN Wireless sold the Commander line to Palstar, where I 
revised all of the design models to bring them into the (then) modern 
age, standardize the production line and make the amps reliable, easier 
to manufacture and service.

I subsequently left Palstar.  When I did they then sold the "new" 
Commander line of amplifiers back to AN Wireless.  To the best of my 
knowledge they were never produced after being handed back to AN Wireless.

73,

Don

On 7/18/20 6:06 PM, Jeff DePolo wrote:
> I have some questions on these amplifiers regarding their history and
> changes made to them over the years.  I know they were originally made by
> Command, and then sold to Palstar, and then back to Command (?), and then to
> AN Wireless?  This one appears to be a very early Command model.  It is
> serial #105, which is presumably #5 off the line.  The lexan front panel
> doesn't have the usual Command Technologies "flag" logo, it just has the
> word "Command" in a plain black font.  None of the documentation I can find
> online, either with Command or Palstar branding on it, seems to match what I
> have.  Some differences I've found between what I have and what I've found
> in the schematics online include:
>
> - There is no two-speed blower operation on this one.  There is a resistor
> in one leg of the AC to slow the blower, but no relay to jump across it to
> speed it up when transmitting.
>
> - There is no grid over-current protection circuitry.  Did that come later?
>
> - One manual I found shows one side of the filament grounded (like this
> one), and a later manual shows it floating.
>
> - A few component value differences (not RF-related), differences in wire
> color codes, etc., nothing major but would be nice to have accurate prints.
>
> Any history on revisions that were made to these amplifiers over the years
> (and why), or a source for schematics that match this presumably-early unit,
> would be helpful.  While I have it open, I may as well incorporate whatever
> improvements I can, especially adding grid protection.  And while I have it
> open, given its age, shotgunning the HV rectifier/filter board would
> probably be wise; is there a better way to get to it that I'm not seeing, or
> does the socket sub-chassis need to be disconnected from everything else and
> removed from the chassis?
>
> On a somewhat related note, has anyone bought tubes from eBay seller "Nevada
> Endeavor"?  They have a listing for "Pre-Order Thomson CSF 3CX800A7".
>
> 					--- Jeff WN3A
>
>
>