Motorola R100/ compact. - UK Vintage Radio Repair and Restoration Discussion Forum

crestavega · 5th Nov 2017, 11:52 am

Is the Motorola "Compact" VHF repeater old enough to be appropriately considered vintage? I am trying to make one good one out of two suspect ones.

Pretty sure that the Tx on one is gubbed, I think the TX deck went into keydown and heat-exhausted its own PA. The other one should be OK but I am not at this stage sure if the RX deck is making COR signal onto the logic board.

Also I appear to have inadvertently reprogrammed a TX code plug EPROM as an RX codeplug and now I cannot change it back to a TX. Not too sure how I have managed to do this as it's supposed to be impossible to rewrite the RX or TX function of a codeplug.

Just a toe in the water to see if anyone out there has intimate knowledge of these creatures.

Jon_G4MDC · 6th Nov 2017, 7:59 pm

Put that into the PMR Engineers thread...

It's usually said they will run screaming to the hills.
I would go running for the tunnels - to avoid the sprogs and intermod.

Weren't these a pair of MC Micros siamesed together in a case somehow.
I remember phono connectors or something like them.

Bad experience in Cork. Not going back!

Biggles · 7th Nov 2017, 8:34 pm

I think I only saw one of these despite working on Motorola gear for a long time. MC Micro's could go into a state of silent (no mod) permanent Tx mode in vehicle installations if the negative supply lead to the battery became high impedance but I never saw this happen with say fixed mobile installations. The MC Micro is a very good radio otherwise. The RF PA is bombproof too. If the compact is indeed based on two Micros, the through chassis interboard connector can cause all sorts of weird problems. All you need to do to cure most of them is to unplug the two boards and exercise the connector. This brings most of them back to life. Don't know why, it just does. The MC Micro had an EEPROM programmed through the software and associated lead/RIB combination. Can't help you with anything more specific than that unfortunately. Most of our stuff was Compa base station repeaters, Spectratac voting and Centracom control rooms linked up with Starpoint/Starplex microwave.
Alan.

5th Nov 2017, 11:52 am	#1
crestavega Pentode Join Date: Apr 2014 Location: Kirkwall, Orkney, UK. Posts: 165	Motorola R100/ compact. Is the Motorola "Compact" VHF repeater old enough to be appropriately considered vintage? I am trying to make one good one out of two suspect ones. Pretty sure that the Tx on one is gubbed, I think the TX deck went into keydown and heat-exhausted its own PA. The other one should be OK but I am not at this stage sure if the RX deck is making COR signal onto the logic board. Also I appear to have inadvertently reprogrammed a TX code plug EPROM as an RX codeplug and now I cannot change it back to a TX. Not too sure how I have managed to do this as it's supposed to be impossible to rewrite the RX or TX function of a codeplug. Just a toe in the water to see if anyone out there has intimate knowledge of these creatures.

6th Nov 2017, 7:59 pm	#2
Jon_G4MDC Nonode Join Date: Nov 2015 Location: Welwyn Garden City, Hertfordshire, UK. Posts: 2,015	Re: Motorola R100/ compact. Put that into the PMR Engineers thread... It's usually said they will run screaming to the hills. I would go running for the tunnels - to avoid the sprogs and intermod. Weren't these a pair of MC Micros siamesed together in a case somehow. I remember phono connectors or something like them. Bad experience in Cork. Not going back!

7th Nov 2017, 8:34 pm	#3
Biggles Rest in Peace Join Date: Feb 2004 Location: Hexham, Northumberland, UK. Posts: 2,234	Re: Motorola R100/ compact. I think I only saw one of these despite working on Motorola gear for a long time. MC Micro's could go into a state of silent (no mod) permanent Tx mode in vehicle installations if the negative supply lead to the battery became high impedance but I never saw this happen with say fixed mobile installations. The MC Micro is a very good radio otherwise. The RF PA is bombproof too. If the compact is indeed based on two Micros, the through chassis interboard connector can cause all sorts of weird problems. All you need to do to cure most of them is to unplug the two boards and exercise the connector. This brings most of them back to life. Don't know why, it just does. The MC Micro had an EEPROM programmed through the software and associated lead/RIB combination. Can't help you with anything more specific than that unfortunately. Most of our stuff was Compa base station repeaters, Spectratac voting and Centracom control rooms linked up with Starpoint/Starplex microwave. Alan.