[Collins] Collins PTO/T-368

[Gerald]

On Tue, 2005-05-31 at 07:25 -0300, David Knepper wrote:
> I picked up two of these PTOs that are used in the T-368.
> 
> Looking for a schematic, particularly, the pin connections, i..e., voltages
> required.
> 
> I see that there is a conversion article on the Internet to retrofit the
> unit to solid-state.
> Any other ideas on their use.  Thought that I would try to get one working
> with my Collins 20V-3, which incidentally is for sale.
> 
> Thank you.
> 
> David, W3ST

There might be a T368 schematic on line. I've never looked. By the
tables I've downloaded (that match a document I have) the T368 PTO is a
70H-9. Tunes 1.5 to 3 MHz, takes 6.3 for heater, ten turns, B+ 150 volts
12 ma. 28 volts for the oven. One sheet says 5 volts open circuit
output. That might be low for driving a vintage crystal oscillator.

There should be minimal resistance (100 ohms or so) between the screen
or plate pins of the output tube to the B+ feed, and none from the
ungrounded heater pin to the hot heater wire (both tubes pulled).
-- 
73, Jerry, K0CQ, Technical Advisor to the CRA
All content copyright Dr. Gerald N. Johnson, electrical engineer