Question about volume control on XTS2500.

[N4KVE]

Between myself, & several friends, we've purchased quite a few XTS2500's in 900, UHF, & VHF. As with all radios, when I turn the radio on, or off, there is a solid click.The exception would be a well used XPR6000 series radio. But on many of these radios, & it doesn't matter if they were made in the USA, or Malaysia, built in 2006, 2012, or 2014, when the radio is already on, & the volume somewhere between the minimum, and the maximum, should I turn the knob to adjust the volume, it will click like the radio is going on, or off even though the knob is nowhere near the off position. The volume control works perfectly & makes no static in the speaker, & feels perfectly smooth when turning it. Just that when it starts to turn anywhere in it's rotation, it clicks just like it was turning on, & off. Some radios do this, while others do not. Anyone seen this, & is there a cure?

 

[MTS2000des]

Gary, sounds like what you describe is the inner part of the volume knob riding against the washer/O-ring underneath. Once the radios get well used, this goes away. It can feel like a click but it really isn't. Sometimes pulling up on the volume knob so it isn't so tight against the washer/O-ring around the control lessens this effect.

I've just taken in around 400 XTS2500s of various flavors to send to surplus, vintage (most from 2008-2011) and they all act this way.

 

[ElroyJetson]

That's called "stiction".

 

[FedFyrGuy]

We use the XTS2500i here in Afghanistan and the volume control has always been the Achilles heel of an otherwise fine radio. Some of the radios are approaching 6 years old are exhibiting the problems described above and some with a complete failure of the volume control. With no repair facilities, radios sidelined for relatively minor problems wind up being turned in for disposal.

 

[MTS2000des]

We use the XTS2500i here in Afghanistan and the volume control has always been the Achilles heel of an otherwise fine radio. Some of the radios are approaching 6 years old are exhibiting the problems described above and some with a complete failure of the volume control. With no repair facilities, radios sidelined for relatively minor problems wind up being turned in for disposal.

The 2500 was a cost-cutter version of a 5000, a one-off of a Waris series radio. They are not designed to be field repaired like a 5000. The volume/channel knobs break right off the boards, the ZIF connectors for the front cover/side connector flex also become problematic.

Nevermind the idiotic idea of placing the UCM on the same board as the front cover keypad.

The radios will usually go to the depot unless you have a really good skilled technician who knows how to use a hot air station.

 

[N4KVE]

Well unfortunately they did not make a 900 MHz XTS5000. Thanks for the reply ERIC, & Merry Christmas. For me an ideal radio would be an APX7000 that does UHF low, & 902/927. Lot's of 900 P25 ham repeaters going up here, & the 2500's do it very well. I'm told the APX4000's will NOT do 902/927.

 

[N4KVE]

Here's the technical explanation from another forum.
There are two ultra-thin, clear, nylon washers below the volume knob when the radios are new. They provide for a frictionless volume knob turn when the radio is already on. If anyone has had the radio apart, those will fall off (unknown to most unless you've been to factory XTS school). When that happens, the bottom of the volume knob sits directly on an adhesive escutcheon on the interior radio top. So, when you turn the volume knob, it has to 'overcome' the sticky surface in order to move. That's why you get the click feel. Those ultra-thin, clear...almost invisible...washers are available from M parts if you want to put them back in. I would. - Jeff
Yes, with two, the lower one's bottom surface sticks to the radio control top adhesive/escutcheon down inside this whole stack, but lets its top surface glide smoothly on the next nylon washer's bottom surface, preventing friction (smooth washer-on-washer action). The top surface of the upper washer touches the bottom of the volume knob plastic. So, from the outside world inward, it goes...volume knob, washer, washer, inside escutcheon/adhesive. Works as intended.

The BSM only says 'washer' (singular), but when you disassemble it during training, they point out that there are two. It's just annotated poorly in the manual vice what you get from the production line.

And I (along with countless others) have run into what you are experiencing from others messing with the radio.

 

[rescue161]

They are Teflon washers and the part number is 0485667D01. They go for about $1.50 each. The one on the top adhesive should not fall off at all, but the other one is just loose and will fall into never never land if you aren't careful. If you are seeing that the bottom washer is falling off, then it would be time to replace the top control adhesive too. I service a ton of these things. Typically, all of the ones that come into our shop have cracked cases near the bottom, so we just build them up with all new parts.

Other problems that we experience with the ones we service are loose volume switches (either loose on the main board or the shaft is loose), loose channel switch (same as volume), SMA loose or broken off of the main board or PTT switch broken off of main board. We repair all of the above and send them back out after alignment. At first, I hated the 2500 and would have rather worked on a 5000, but I've grown to like the 2500.

Our users are extremely rough on radios. Here is one of the better ones that came into the shop.

 

[N4KVE]

Fixed. Removed the volume knob, & the seals were there. So I applied a tiny amount of white industrial lithium grease to the bottom of the knob where any rubbing could take place. Good as new now. This radio is 4 years old, & was barely used for 2 years, & spent the last 2 years in a drawer, so it has had an easy life. Now to tell my friends how to fix theirs.

 

[rescue161]

Be careful as once that grease gets under the adhesive, the top contol escutcheon can pop off.