[Boatanchors] W2EWL VFO range? New Question

[k9muf at comcast.net]

And since the topic is phasing SSB rigs, reminds me that I have a Barker & Williamson audio phase shift network model 350/2Q4 if anybody is interested.

Don   K9MUF

----- Original Message -----
From: David C. Hallam <dhallam at knology.net>
To: boatanchors at mailman.qth.net
Sent: Tue, 22 Mar 2011 17:17:28 -0000 (UTC)
Subject: Re: [Boatanchors] W2EWL VFO range? New Question

Sine the topic is phasing SSB rigs, I am going to ask for ideas with a 
Johnson Pacemaker I am refurbishing. Johnson went a different route in 
the Pacemaker. The SSB signal was generated at a different frequency on 
each band and then mixed with Johnson's standard vfo, 3-3.5 MHz.

My problem lies in the RF phasing circuit. On some bands, particularly 
40 & 20, I am getting harmonic output from the crystal oscillator. On 40 
the oscillator is 4 MHz and 20 is 11 MHz. Each of the 5 crystal 
oscillators has its own tuned circuit, slug tuned coil and capacitor. 
Johnson says to tune each oscillator to maximum output OR 1.5V RF 
whichever is less.

With the harmonic content of the oscillator, I can not get the required 
90 degree phase shift. for the balanced modulator. The coils and 
capacitors are a bear to get to and I have not measured the inductance 
or capacitance of the components. I have tried different crystals.

Ideas?

David
KW4DH

On 3/22/2011 12:31 PM, Robert Nickels wrote:
> On 3/22/2011 10:48 AM, D C *Mac* Macdonald wrote:
>> Single conversion could theortically cover 3.7-5.0 with a subtraction
>> mixing scheme and 13.0 - 14.3 by using an addition mixing simply
>> by tuning the final (IIRC).
>>
> These basic phasing rigs are a great learning experience and I have to
> admire you guys who tackled such a project back in the Eisenhower era!
>
> 73, Bob W9RAN
> ______________________________________________________________
> Boatanchors mailing list
> Home: http://mailman.qth.net/mailman/listinfo/boatanchors
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:Boatanchors at mailman.qth.net
>
> List Administrator: Duane Fischer, W8DBF
> ** For Assistance: dfischer at usol.com **
>
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>

-- 
“I bring reason to your ears, and, in language as plain as ABC, hold up truth to your eyes.” Thomas Paine, December 23, 1776

______________________________________________________________
Boatanchors mailing list
Home: http://mailman.qth.net/mailman/listinfo/boatanchors
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Boatanchors at mailman.qth.net

List Administrator: Duane Fischer, W8DBF
** For Assistance: dfischer at usol.com ** 


This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html