Hi to All,

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We have many Motorola MSR2000 VHF, UHF and cross-Band RX VHF TX UHF station still on the air and they have a common Molex plug intermittence on the audio and control card’s.

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Every couple of years’ they start to have intermittent problem’s and we have to go to the site and pull out an in a few time all the card and the station return to normal use

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I know it is very common in commercial use to pull out all the cars and use an external controller like a CSI or Zetron, that could be applied to certain station like our cross-band one.

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But some are a voting station connected to a Motorola Spectra-Tac and some are RF Link I would need 3 Zetron to do it…

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Si I am looking to keep using the original Motorola card’s but find a fix to the contact problem.

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Doe’s anybody ever found a fix to this common problem?

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For info here are the card’s we use:

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Line Driver (to drive audio to the RF link)

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Station Control (to control the station)

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Squelch-Gate (for local repeat operation)

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Original Motorola Morse ID

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PL Card for RX and TX CTCSS

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R1 Audio (the Squelch control the audio going to the RF Link)

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Time-Out Timer

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Any suggestion would appreciated.

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Best 73 to All.

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Carl

VA2CMB

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Thank you for all the info JB.

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We have many Micor still in service and we rarely have this problem with them. Compared to the MSR2000.

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I was thinking the difference is the Micor female pin is all around the Male pin compare to the MSR pin touch only on one side in the molex…

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Best 73

Carl

VA2CMB

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De?: [email protected] [mailto:[email protected]] De la part de jb via groups.io
贰苍惫辞测é?: 13 novembre 2022 13:38
??: [email protected]
Objet?: Re: [repeater-builder] MSR2000 Molex Plug problem

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Tin plating was one of the biggest recalls with micor and later radios.? You could order contacts in bulk and
replace them as needed.? Big job.? For some radios they came up with gold plated contact replacement
kits that fixed it for good.? You would have to get lucky with NOS barn find.? A real big job for so many contacts,
but the only fix that lasts except for wiring jumpers around every contact that fails (I have seen this abomination).?
Many of the MSR cards are identical to the micor except for the edge connector.? It is too bad that the cards
are so reliable and robust EXCEPT for the edge connectors.

The tin plating will oxidate at the contact point over time and only wiping or scraping through will restore
for a time.? I always used 90% isopropyl and work the contacts.? I found out there could be problems with Silicone?
or "active" ingredients, especially any where near RF connectors, plastics or circuits.? If you can reach the pins,
you can scrape out the oxidized line where the contacts mated.? I don't know what is in Stabilant, and their SDS
doesn't say what the secret sauce is and I never used it before.? I have used DeOxit but you have to be real careful.?
If the sauce claims to be a contact enhancer, it probably has a weak acid or some other active ingredient.? You only?
know if it's safe after long term experiments.? Nothing really works better than replacing with gold.? Fast was most
important, so rather than tracing out the bad contact, we would just wet the card edge and work it and come back
in 6 months to do it again.

The external controller is a good way to go if you want some feature that just isn't in the stock setup.? My head
would spin to figure out how to integrate an external controller in such a way that I could unplug it and flip over
the cards in the cage and revert to stock without some fiddler blowing something up not understanding what
they were seeing.?

Many radios and TVs of the day suffered copy cat problems.? They all thought board swapping would be the wave
of the future, but contact service became the major service issue.? Mastr2 had some problems too.? The Quasar
"works in a drawer" TV became a joke.? We could get them working but there was so much flex in the chassis that
when we slid it all back together it would fail, or the ride back to the customer and it would fail.? Service people
would snicker and "never works in a drawer" and "quality goes out before the name goes on" would be muttered.?
I would surmise the design team was outvoted by the bean counter and advertising to the point of major FAIL.
Mot got out of the TV business completely and sold the Quasar name to a Japanese company.