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Vintage Amateur and Military Radio Amateur/military receivers and transmitters, morse, and any other related vintage comms equipment. |
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18th Jul 2021, 9:56 am | #1 |
Triode
Join Date: Jun 2020
Location: Yalding, Maidstone, Kent, UK.
Posts: 35
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PYE PF85 - schematic - info
Picked up a PF85 plus car kit and lapel mike at boot fair - without battery. Applied 9 volts and it behaves like a radio and puts out about 137MHz and draws about 170mA on PTT.
Now wondering what to do with it. Basically looks like a conventional NBFM radio. To do much with it would need to alter the LO and disable the squelch. Made a bit more difficult by the mysterious OM601, 603, 602 and 605 modules. Are schematics available? And what was the 'proper' battery voltage and how long the 'rubber duck'? BTW, the car kit draws 150mA and makes a hiss but the radio does not work in it - maybe because the battery is missing? |
18th Jul 2021, 10:04 am | #2 |
Nonode
Join Date: Nov 2015
Location: Welwyn Garden City, Hertfordshire, UK.
Posts: 2,015
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Re: PYE PF85 - schematic - info
9.6V is correct. 8 x 1.2V Nicads were in the pack. There is a fuse under a sliding cover which is part of the battery connection gubbins on the base of the set.
Schematics of the modules were never available only an interconnection diagram. Unlike most P5000 modules you can't get in the ceramic coated ones to fix them. If they are faulty they are scrap. 137MHz sounds like Gas/Electricity was the original user. You are right it's NBFM only with direct FM of the crystals on TX. If it is A1 Band then it's a good prospect to convert to 2m amateur band, most were A2 and needed capacitor changes to get the RX front end to tune. At least that module can be worked on. Last edited by Jon_G4MDC; 18th Jul 2021 at 10:16 am. Reason: Banding corrected to match the spec brochure which follows! |
18th Jul 2021, 10:06 am | #3 |
Moderator
Join Date: Jan 2003
Location: Ipswich, Suffolk, IP4, UK.
Posts: 21,289
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Re: PYE PF85 - schematic - info
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Graham. Forum Moderator Reach for your meter before you reach for your soldering iron. |
18th Jul 2021, 12:21 pm | #4 |
Tetrode
Join Date: Dec 2012
Location: Andover, Hampshire, UK.
Posts: 85
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Re: PYE PF85 - schematic - info
I have a pdf of the service manual. PM your email address.
Regards, John |
19th Jul 2021, 8:54 am | #5 |
Heptode
Join Date: Sep 2006
Location: Woodbridge, Suffolk, UK.
Posts: 643
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Re: PYE PF85 - schematic - info
If its transmitting 137Mhz then its a B1 which is 132-146Mhz, according to page 148 of the late Chris Lorek's second PMR conversion book.
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Dave G1AGK. My perception is my reality! |
19th Jul 2021, 10:29 am | #6 |
Nonode
Join Date: Nov 2015
Location: Welwyn Garden City, Hertfordshire, UK.
Posts: 2,015
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Re: PYE PF85 - schematic - info
Thanks for the reminder of rather rusty memory. Of course it was..
It even says so in the brochure linked by Graham in post#3 |