Hi Jerry,
The Corsair II fold-out shows the PTO output routed to the 80975
Oscillator-Mixer board. The signal splits at that point going to U1, the TL442
mixer IC, for all bands except 20 meters, and then to a 270 ohm/150 ohm divider
for 20 meters. That divider consisting of 420 ohms total resistance and is
likely the majority loading for the PTO output. I do think all of the other
impedances seen by its output are much higher.
Interestingly my mixer IC is not the rare TL442, but instead an MC1496. I heard
long ago that the TL442 had a limited production time and Ten Tec scrambled to
retrofit the MC1496 into the mixer role. It is still very available today,
while the TL442 is past history. My mixer board doesn't have any of the
silkscreened component numbers, or outlines.
'73, Thomas - ac7a
________________________________
From: Jerry Haigwood <jerry@w5jh.net>
To: Discussion of Ten-Tec Equipment <tentec@contesting.com>
Sent: Monday, March 24, 2014 7:11 PM
Subject: Re: [TenTec] Corsair II, PTO output level
Hi Steve,
What was the load impedance?
Jerry W5JH
"building something without experimenting is just solder practice"
----- Original Message -----
From: "Steve Hunt" <steve@karinya.net>
To: "Discussion of Ten-Tec Equipment" <tentec@contesting.com>
Sent: Monday, March 24, 2014 3:34 PM
Subject: Re: [TenTec] Corsair II, PTO output level
> All four of mine measure close to 1.2v p/p
>
> Steve G3TXQ
>
>
>
> On 24/03/2014 20:06, Thomas Kuehl wrote:
>> Hi,
>> Does anyone know what the correct peak-to-peak output level is for a
>> properly working Corsair II PTO?
>> Any assistance is appreciated.
>> '73, Thomas - ac7a
>> _______________________________________________
>> TenTec mailing list
>> TenTec@contesting.com
>> http://lists.contesting.com/mailman/listinfo/tentec
>>
>>
>
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