Bob and Lee,
Mouser Electronics lists a line of C0G (NP0) ceramic, radial leaded
capacitors in their current catalog. They range in value from 10 pf to
0.022 microfarad. I can give you the part number for any value you might be
interested in, or you can look them up yourselves. Start off at
http://www.mouser.com/Search/Refine.aspx?Ne=254016&N=1323038+254340+4294759694
and go from there.
Jim, W8KGI
----- Original Message -----
From: "Bwana Bob" <wb2vuf@gti.net>
To: <lberman@alumni.neu.edu>; "Discussion of Ten-Tec Equipment"
<tentec@contesting.com>
Sent: Tuesday, April 21, 2009 5:50 PM
Subject: Re: [TenTec] DDS VFO as remote VFO?
> Lee:
>
> The easiest way to fix thermal drift is to change the temperature
> compensating capacitor in the PTO. This is the cap that is shown as
> "value selected in production" on the PTO schematic. You will need to
> try different values of capacitor and they must be of the N750 (negative
> 750 ppm) type. Unfortunately, N750 caps are hard to find. Maybe Ten Tec
> has some spares.
>
> 73,
>
> Bob WB2VUF
>
> lee berman wrote:
> > I am attempting to correct the thermal drift on my 580 Delta PTO, by
> > using a Direct Digitally Synthesized VFO as a remote VFO. The DDS
> > output is said to be ~500mV P-P (I've not measured it myself). To date,
> > I had no success. I wonder if anyone else on this reflector has
> > successfully done this and can point me in the right direction. The
> > unit I'm trying is the one by N3ZI.
> > Other "fixes", such as PTO rebuild, and the K4DPK unit have worked well
> > for many other hams, but not me. The drift is definitely in the PTO,
> > defintely thermally induced and does not settle out after hours of on
> > time, so this is my latest effort at ending it.
> > thanks, ~Lee, W1IDZ
> >
> >
> >
> >
> >
> > _______________________________________________
> > TenTec mailing list
> > TenTec@contesting.com
> > http://lists.contesting.com/mailman/listinfo/tentec
> >
> >
>
>
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