Hi Andy Yes I have that one....I'll look out a scan
Alan G3NYK
----- Original Message ----- 
From: "Andy Talbot" <[email protected]>
To: <[email protected]>
Sent: Sunday, November 07, 2010 10:03 AM
Subject: Re: LF: exciter for 137 and 500 kHz


> Nice little prog - I'd love to see the source code :-)
>
> Taken from that reference :-
> "*The calculations to derive the time constants and therefore the 90
degree
> frequencies, and the component values, were based on equations in the
> article by Dr. (Eng) Ralph Oppelt, DB2NP, published in VHF Communications
> Volume No. 18, Summer, 2/1987.*"
>
> Does anyone have back copies of VHF Comms ???
>
> Andy
> www.g4jnt.com
>
>
> On 7 November 2010 03:59, <[email protected]> wrote:
>
> >  Andy
> >
> > It's been a while ... but believe I used this online calculator.
> >
> > http://www.werewoolf.org.je/apf.htm
> >
> > Jay
> >
> >
> >
> > ----- Original Message -----
> > *From:* Andy Talbot <[email protected]>
> > *To:* [email protected]
> > *Sent:* Saturday, November 06, 2010 9:59 AM
> > *Subject:* Re: LF: exciter for 137 and 500 kHz
> >
> > Very Interesting.
> > Where did you find the design data for the allpass network?   I've only
> > been able to find the values for up to 3+3 allpass stages.
> >
> > Mind you, at that number of chips a DSPic begins to look attractive.
> >
> >
> > Andy
> > www.g4jnt.com
> >
> >
> > On 6 November 2010 11:52, <[email protected]> wrote:
> >
> >> Nothing earth shattering ... another way to skin the cat. The 137 and
500
> >> kHz units have been in use for a few years ... just now getting around
to
> >> the write up.
> >>
> >> http://www.w1vd.com/137-500Phasingexciter.html
> >>
> >> Jay W1VD  WD2XNS  WE2XGR/2
> >>
> >>
> >
>