Regency MX3000 Volume Pot Repair

[KJ6HCB]

Ive seen a few mentions of it, the volume (and squelch) pots fail. It seems thats the case with mine as the knob turns it on, but its stuck at a single volume. Does anyone have the correct part number or cross reference for a pot that will work, or will the RS geeks know what to get if I take in the old one?

 

[BigJimbo]

I have an MX-3000 running in my home shack. It needed repair earlier this year.

Best thing to do to get it running right again is to send it to G & G Electronics. Vintage scanners are their specialty. Turnaround is usually less than a month and costs are reasonable too.

Gerry has tons of parts for these old type scanners.....he will take good care of you.

 

[KJ6HCB]

Thanks for the info, but not worth it to me. It was a $5 swap meet find. Audio works but is stuck on a somewhat low volume. For a $3 or so pot down at Radio Shack and 10 minutes of my time to solder Ill fix it, otherwise it can hang out on the shelf. Thanks!

 

[BigJimbo]

Understood.

I'm sure Gerry can give you the right part numbers if you cant find them on your own.

Good luck.

 

[WA1ATA]

Thanks for the info, but not worth it to me. It was a $5 swap meet find. Audio works but is stuck on a somewhat low volume. For a $3 or so pot down at Radio Shack and 10 minutes of my time to solder Ill fix it, otherwise it can hang out on the shelf. Thanks!

Your best course of action would probably be to first unsolder the pot and remove it.

Then you can just measure it with a DMM to get the total resistance, and then by measuring at a couple of rotation angles you can probably figure out what sort of taper (linear, logarithmic, etc) it is. Having it in your hand when looking at possible Radio Shack substitutes also makes it more likely that you will get on that is a physical match also.


Charlie

 

[tonyclark]

Most of the time the value is stamped right on the pot itself 5k, 10k, 20k and so on. open it up and look.

 

[talkpair]

MX3000 Volume control

According to the maintenance manual I have, the Volume and on/off switch is designated as R301 on the schematic.......variable, 10K........no taper information or shaft dimensions.
The Regency part number is 4751-3294-801

The squelch control is also a 10K, without the switch.........designated R302....Regency part number 4751-3278-101

G and G....Scanners and Scanner Parts

Looks like g&g has the squelch pot, but not the volume control pot.

Perhaps you can pull the on/off switch from your old pot and put it on the new one.

 

[W2PMX]

The taper on a volume pot is called, surprisingly, "audio taper". Any taper will work, but with the wrong taper, the level you want might be at one end of the control, where just looking at it will make it too high or low, while the rest of the control is all about the same level. But a linear taper pot will work fairly well as a volume control if you can't get an audio taper pot.

From what I see on the RS site, though, they're not going to be much help. The only pot with switch they list is a 500k control. It may work, but that depends on the circuit. (It won't damage anything, it might just not give you a smooth change in volume.) A Mouser 31XP401-F would be just what you need. I don't know what they charge for shipping, but the part is $2.

 

[mastr]

The pot is held together by three metal tabs, which become loose and create problems. It is easy to open the pot up, spray a bit of whatever your farorite cleaner is on it then bend the tabs back over. Secure them with a bit of silicone if you want. Takes more time to get the pot out and back in than to "fix" the pot, but it isn't a "10 minute" job unless you have done a bunch of them.

The volume/squelch pots for the Regency RH250 mobile radio are workable, but not exact replacements. There is also a plastic reinforcement ring that was used on the RH250 that can be installed to make things slightly more durable.

I have one that is easily 25 years old. It is going on its 3rd or 4th keyboard and I have done the volume/squelch pot repair countless times.