[MRCA] PRC-127

[Robert Newberry]

After more research I found out the 127 is a basically an LPH. Found the
reference adjustment and everything is fine business.

Apparare Scientior
Paratus Communicare
-N1XBM
On Jul 30, 2013 1:39 PM, "B. Smith" <smithab11 at comcast.net> wrote:

>  I think I would calibrate the time base in the counter first. If it is
> 10 Mc you can easily beat it against WWV and get it down to a 2 or 3
> cycles-  - -, just listen for the wump wump wummmmp .  :-)
> Then immediately take your readings.
>
> Z
>
>
> On 7/30/2013 9:29 AM, Robert Newberry wrote:
>
> 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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