[Milsurplus] MOSFET High Voltage Regulator Circuit

[Mack]

Dennis,

Thank you for your suggestion. I have the oscillator relay contacts closing 
first and I'm tapping off my PS bleeder resistor for the oscillator. Mind 
you, the chirp isn't horrible just not to my standards. I've never tried a 
1625 as a regulator but will investigate that approach.

Four primary approaches I'm investigating so far: (reposted here in case 
others are following this thread)
1. MOSFET regulator as suggested by Jeff N2LXM. He sent a very simple 
schematic that looks very promising and I've ordered the parts from Mouser 
to prototype.
2. HV switching chip as suggsted by Peter
http://www.onsemi.com/pub_link/Collateral/MC33363B-D.PDF
3. TV Horizontal flyback transistor.
4. OC3 regulators in series.
5. 1625 as a regulator.
6. Separate regulated HV power supply from Martin P. Jones and Assoc in Lake 
Park, FL. PN 8529-PS.

I'll report back mid next week with the results using the MOSFET after the 
parts arrive from Mouser.

Thank, as always, to everyone for your excellent suggestions. Happy New 
Year!

73,

Mack de WB4MAK
www.nfarl.org
www.sedxc.org

--------------------------------------------------
From: "mac" <w7qho at aol.com>
Sent: Saturday, December 26, 2009 03:07
To: "Mack" <mccormick_mack at hotmail.com>
Cc: "MilSurplus QSLNet" <milsurplus at mailman.qth.net>
Subject: Re: [Milsurplus] MOSFET High Voltage Regulator Circuit

> Mack,
>
> I take it you're using the original keying relay in the ARC-5 (K-53) 
> which makes and breaks the B+ line to the oscillator tube and the 
> cathodes-to-ground circuit on the 1625s.  Question -- How are you 
> deriving the oscillator voltage, i.e., via a simple dropping resistor 
> from your 600 volt HV supply?  The oscillator circuit in the ARC-5 is  not 
> particularly voltage sensitive but 600 to 200 on key-down is a  heck of a 
> swing and not too surprising you're getting some chirp.  You  might try a 
> tap off your PS bleeder resistor to supply the oscillator  voltage and see 
> if that cures the chirp problem.
>
> If you determine you still need to regulate suggest you try a vacuum  tube 
> based electronic
> circuit . Single 1625 series tube would handle the 400 volt drop at  20ma 
> you're talking about.  Circuits to be found in 50's/60/s ARRL  handbooks.
>
> Dennis D. W7QHO
> Glendale, CA
>
>
>
> On Dec 25, 2009, at 2:00 PM, Mack wrote (in part):
>
>> Merry Christmas!
>>
>> I've almost completed my ARC-5 transmitter/receiver project but I  have a 
>> small amount of chirp when keying. I've confirmed it's the  200V I'm 
>> feeding  to the oscillator plate not being stable. I can  eliminate the 
>> chirp by using my regulated bench HV supply........
>>
>
>