[MRCA] PRC-127

[Robert Newberry]

My freq counter says at 136.000 programmed. Reads 136.00199. Programmed
160.0000. Reads 160.00225.

It is also off consistently by approximately that much on all channels.

Apparare Scientior
Paratus Communicare
-N1XBM
On Jul 30, 2013 8:42 AM, "Ray Fantini" <RAFANTINI at salisbury.edu> wrote:

> Important after thought, if the radio is on channel on any channel the
> reference oscillator is correct! Check the error on the lowest programmable
> channel around 136 MHz and the highest channel 160 MHz and although the
> percentage of error may be different if there is no error on some channels
> and error on others it's not a reference problem, in that case you have a
> divider problem and throw the radio away! But if you see a consistent error
> that increases with frequency like your describing would assume that your
> reference oscillator is a little off.
> Ray F
>
> -----Original Message-----
> From: mrca-bounces at mailman.qth.net [mailto:mrca-bounces at mailman.qth.net]
> On Behalf Of Ray Fantini
> Sent: Tuesday, July 30, 2013 8:30 AM
> To: Robert N. Newberry; mrca at mailman.qth.net
> Subject: Re: [MRCA] PRC-127
>
> It's pure speculation on my part not having worked on a 127 before but
> most synthesized radios built around that time are designed around an
> internal fixed reference oscillator and a programmable divider chain that
> controls a PLL. Being that the radio will channel and if it accepts program
> changes would assume that the divider chain and PLL are all working and it
> may just be that your reference oscillator is not on frequency. Be cautious
> because a small change in the reference oscillator will result in a big
> change in operating frequency. Al lot of stuff produced back in the
> seventies and eighties worked with reference oscillators in the 5 or 10 MHz
> range. Newer radios used sealed reference oscillators but things that old
> often had discreet component oscillators. But if you can enter new channels
> and the radio is somewhat on channel the synthesizer is working so don't
> mess with things like the VCO or PLL system because that will only get you
> in trouble, good luck.
> Ray F
>
> -----Original Message-----
> From: mrca-bounces at mailman.qth.net [mailto:mrca-bounces at mailman.qth.net]
> On Behalf Of Robert N. Newberry
> Sent: Monday, July 29, 2013 10:07 PM
> To: mrca at mailman.qth.net
> Subject: Re: [MRCA] PRC-127
>
> I should of specified by high in frequency I mean frequency error.
>
>
>
> On 7/29/2013 10:08 PM, fred anderson wrote:
> > There is an old DOS program call ham n eggs which reprogrammed the PRC
> > 127 to the Ham Band
> >
> >
> >
> > Fred KB4DMQ
> >
> >
> >
> > From: mrca-bounces at mailman.qth.net
> > [mailto:mrca-bounces at mailman.qth.net] On Behalf Of Robert Newberry
> > Sent: Monday, July 29, 2013 4:18 PM
> > To: mrca at mailman.qth.net
> > Subject: [MRCA] PRC-127
> >
> >
> >
> > I have a PRC-127 that is a little high in frequency. I've skimmed thru
> > TM
> > 11-5820-1048-24 but I didn't see anything about adjustment.
> >
> > Anyone know where to find adjustment info?
> >
> > Apparare Scientior
> > Paratus Communicare
> > -N1XBM
> >
> >
>
>
>
>
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