Broken channel selector knobs on MT1000's,

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Charlied
Posts: 80
Joined: Mon Feb 10, 2003 1:15 pm
What radios do you own?: MTS2000

Broken channel selector knobs on MT1000's,

Post by Charlied »

possibly others.

Gorilla glue works.

I had my doubts.

I add so little to the site, I just had to jump all over this one.
KI4ISE
RadioSouth
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Post by RadioSouth »

Probably won't last long. The Genesis series knobs seem to dry out and just self disintegrate over time. I've replaced at least half the knobs on my Genesis radios (have 12 of them) and none were broken until they were turned then just fell apart. The speaker mics for this series aren't much better either, strain reliefs just turn to a tarry ooze, granted they were stored about a year in a warm garage, but to just break down like this pretty much sux.
Will
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Post by Will »

Radio South is correct. Only thing to do is order new knobs, and yes Motorola did change vendors/design.

Have the same problem with the spkr/mic cables and strain releifs. The angle strain relief is still available.
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kb0nly
AKA: The Computer Doctor
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Post by kb0nly »

Yep, been there done that, plenty of dried out knobs that look good until you try to use it. They don't break, they just crumble.. They didn't use the best plastic for them evidently.
Duct tape is like the force, it has a dark side and a light side and it holds the universe together.

"I Reject Your Reality And Substitute My Own!" - Adam Savage
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WA3VJB
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Post by WA3VJB »

Damndest thing, but true, and apparently heat or sunlight related (UV). I have several mint HT600 and MT1000 examples that were stored somewhere near a window (maybe on the ledge???) and the knobs turned brittle, and cracked as soon as you put torque to them.

Same thing looks like it's happening on the PTT "lever" as they call it, that thin plastic rectangle over the push to talk button. Characteristic signs include a white milky surface of oxidation (or separation of plastic polymers) that you can wipe off.

I've got one of them that cracked the other week.
Order replacements while you can stil get them. Knobs are about $5, SQ/CH and the PTT lever is under a buck.
Last edited by WA3VJB on Thu Jan 16, 2014 3:43 am, edited 1 time in total.
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kb0nly
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Post by kb0nly »

I've had a lot of them with the milky white PTT piece. I remember when i first started working on them i thought it was dust dirt or dust, but scrub as you may they won't ever totally come clean.

At least the plastic of the cases seems to be stable.
Duct tape is like the force, it has a dark side and a light side and it holds the universe together.

"I Reject Your Reality And Substitute My Own!" - Adam Savage
ve7wdm
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Re: Broken channel selector knobs on MT1000's,

Post by ve7wdm »

I, too, have noted this strange deteriation. Unfortunately, I have three unused, mint condition HT600's (with consecutive serial numbers) who's knobs have completely crumbled to dust. :-(. Has anyone on the forums got any replacements they'd like to sell? -Wes Martin.
RadioSouth
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Re: Broken channel selector knobs on MT1000's,

Post by RadioSouth »

They've been NLA for quite a while. I'm using MT500 knobs (metal) as a permanent fix. Channel dot on the knob doesn't line up to the right channel but the Vol. knob is perfect.
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TomSlick
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Re: Broken channel selector knobs on MT1000's,

Post by TomSlick »

Sounds like a perfect job for someone with a 3D printer and some spare time.
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WA3VJB
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Re: Broken channel selector knobs on MT1000's,

Post by WA3VJB »

RadioSouth wrote:They've been NLA for quite a while. I'm using MT500 knobs (metal) as a permanent fix. Channel dot on the knob doesn't line up to the right channel but the Vol. knob is perfect.
Yes, I found that advice for the substitute knob on this board ! Many thanks. Here's what it looks like, installed:

Image

I found that the volume control shaft size is a little bigger on the MT1000 and I had to drill the MT500 knob a little to make it work. Still plenty of perch for the threaded key to tighten with.

Which reminds me, is there a known size to ask for when trying to buy the hex spline that fits these knobs? It's not a standard hex, with an extra flute on the flat sides. I've seen this type on knobs for military receivers, I think they're called hex spline rather than the conventional "Allen" type. I used to have one with my HT220 but it's long lost.
AL7OC
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What radios do you own?: Motorola, Icom, Thales, Tekk

Re: Broken channel selector knobs on MT1000's,

Post by AL7OC »

I think that they are known as Bristol splines. You can find sets online.

PL
Pierre

AL7OC
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