[ARC5] Considering GO-9 Transmitter Power Options.

[Richard Knoppow]

    This is a great idea. For instance, I found my BCC-779 
Super-Pro oscillator pulled with the AVC. The AVC or manual RF 
gain affects the B+. Adding a VR tube fixed the pulling but 
generates some heat. This looks like a much better solution.

On 9/3/2019 6:12 AM, David Stinson wrote:
> 
> On 9/2/2019 12:21 PM, howard holden wrote:
>  >
>  > ... a commercial regulated supply which puts out 350VDC...
>  >I opted to try keying the center tap of the 837 filament trans
>  >through its 1000 ohm resistor, which happens to work
>  >just fine. I know keying the VFO is a supposed “no-no”,
>  >but chirp is almost non-existent, and stability is exceptional
>  >for an 80 year old transmitter...
> 
> Good tips.  I've also found that one key to stability and 
> chirp-less keying is good, hard regulation of the supply to the 
> MO, assuming it can  source the needed current.  Regulating any 
> voltage up to thousands is childs-play now with MOSFET regulators 
> and just a few parts.  FETs that  can regulate 3000V for you are 
> like $15 and those for typical MO supplies can be had NOS for a 
> couple of bucks.  One can build and incorporate the circuit in a 
> couple of hours.   The Australian AT5/AR8 is powered by a ham rig 
> 12V mobile supply.  It "sang like a bird" until I tacked-together 
> a FET regulator for the Osc. supply.  Now the keying (and 
> stability) are nearly as good as the $10,000 plastic "Barbie and 
> Ken" radios one can buy today.
> P.S. Attached diagram:  "Stack to unregulated voltage" means the 
> unregulated voltage under the intended load.  I use 5W zeners, 
> just because they're cheap and look cool ;-)
> 
> GL OM ES 73 DE Dave AB5S
> 
> 
> 
> 
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-- 
Richard Knoppow
1oldlens1 at ix.netcom.com
WB6KBL