BC125AT Post Release Thread

[SCPD]

Ticking noise.

Does anybody else besides me hear a ticking noise mainly on VHF frequency's. On some frequency's it is almost louder than the voice transmission. When there are no transmissions and you turn the squelch off you can here it in the background noise. I thought it was electrical interference then I figured it was sunspot activity. Now I think it must have something to do with the internal CPU clock frequency, whatever that is. I wish it could be fixed. This has also been posted on the Yahoo groups. Hopefully Paul Opitz can check this out and advise.
Denis Jackson

 

[scannersnstuff]

Does anybody else besides me hear a ticking noise mainly on VHF frequency's. On some frequency's it is almost louder than the voice transmission. When there are no transmissions and you turn the squelch off you can here it in the background noise. I thought it was electrical interference then I figured it was sunspot activity. Now I think it must have something to do with the internal CPU clock frequency, whatever that is. I wish it could be fixed. This has also been posted on the Yahoo groups. Hopefully Paul Opitz can check this out and advise.
Denis Jackson

yes,i initially reported this when giving the radio my mini review. it was very prominent on 154.295. i put it in as 154.300 mhz. it helped somewhat.

 

[nanZor]

I hear a few of them in vhf airband as well - well under the squelch but sometimes I can hear the ticking underneath audio when it does open for comms on a few frequencies. Not enough to be a showstopper, but it is noticeable sometimes. Like 128.375, but it is strongest on 128.3833 mhz.

I don't hear it when the antenna is removed - aha you say- BUT I don't hear it on ANY other scanner I have. I tried using Close Call on a 396 to see if anything jumps out - but no, it's clean. Seems like it needs an antenna to pick up whatever is causing it internally.

 

[DaveIN]

If you remove the antenna and the tick goes away it has to be a signal source from somewhere. If it was an "internally" generated signal (birdie) then it should remain when the antenna is removed.

Denis sounds like he has a different problem if it's nearly louder than his active frequency with voice.

Are all the Close Call settings off, WX alert off, as well as priority?

 

[nanZor]

If you remove the antenna and the tick goes away it has to be a signal source from somewhere. If it was an "internally" generated signal (birdie) then it should remain when the antenna is removed.

That was my immediate thought - but none of my other radios detect it (396xt / Icom R20, Icom T7H, Vertex VXA300, BC370CRS, Pro137, 72/95xlt or even a Grundig 750). It doesn't matter if I'm at home, work, or out in a field. And it isn't like any birdie I'm used to - typically clean beats or whistles - this has a raspy little clock-pulse sound to it.

Actually I was excited at first - hey cool, this thing is detecting the pulses from one of my battery chargers going off somewhere - but no.

Are all the Close Call settings off, WX alert off, as well as priority?

Yes, and operating solely from batteries too.

Could be that the addition of an antenna is providing a nice way for the clock to get OUT and then get detected directly back through the case maybe - don't know. I even tried putting all my bandpass filters on to see if that made a difference - even to a "race stubby" Diamond SRH805S+adapter. (AOR, PAR airband bandpass filters - civil , milair, fm notch, etc)

I can also make the pulse jump/reset by toggling the lcd backlight. The jump is most noticeable with the keybeeps turned off and then doing the toggling.

Just so everyone knows - I LOVE this 125AT, and not trying to make this out to be a showstopper issue. I'd pick another one up in a heartbeat. Might sell off my 72/95xlt to do so!

 

[elmocoh]

Ticking Noise

I hear the ticking noise on certain frequencies, both VHF and UHF. The noise is apparent only when receiving a signal. It's no surprise that you don't hear it when you remove the antenna; no signal, no noise.

 

[nanZor]

Then why isn't this ticking heard on all my other radios? I also tested with the same antennas, in the same position, and none of them pick that up. AND why can I actually manipulate the pulse by using the backlight switch, LO, or other keyboard activity? The keyboard doesn't just mute it temporarily, you can hear it restarting / jumping into the cycle.

There is also a thread that poo-poohed this very same observation about the birdies heard on the 72 and 95xlt's in vhf low-band. In this case, the birdies are clean, and strong enough to break the squelch when searching. What was maddening is that the birdies are walking - that is, they slowly move upwards in frequency. So if you listen long enough, the birdie moves - which makes it impractical to just do a lock out - or just put up with it for 20 seconds or so as it moves off frequency. Eventually it rolls around again.

And, just like this case, when you pull the antenna, the birdies aren't detected so an external noise source is determined by others to be the culprit, and the owners just don't know what they are talking about.

I'm in Los Angeles, and another user in Australia noticed the same thing and we went over this here as well. As experienced users, the first thing we went looking for was an external source and found it to be internal. But since most people don't care about vhf low anymore, and you could just write it off as something external - proved by the use of an antenna in the first place, the situation is ignored.

In fact, I used my 396xt to try and track down what I thought was the sweeping noise source affecting my 72/95's. To my dismay, the 396xt had the same issue on vhf-lo, on a narrower spectrum, only it was VERY muted, much slower to sweep, AND would not break squelch - so most won't notice it. You really got to dig for it on the 396.

Now, we are in the same boat - only the birdie is stable on a number of frequencies, but with a raspy clock pulse. It does not break squelch, but if it is on a frequency you have programmed, AND communications occur, you can hearing it mixed in with the audio on SOME frequencies. Of course, you have to have the antenna attached to notice it, which puts us back into user-error territory vicious circle.

Because it won't break squelch, it would take forever to find them with the squelch open on the 125AT. I started to slowly manually search with the squelch open, and found them also on the same frequencies the others mentioned, but also on 118.475, 119.2333, 134.4833 etc. They were lower in amplitude than the one on 128.375 (louder on 128.3833). The three frequencies first listed are not a problem for me since I don't have those programmed and they do not break squelch - even with the antenna attached - but they are there. I don't have time to move step by step through the spectrum with the squelch open.

I could easily see this going the same way the 72/95xlt vhf-low birdie issue goes - the owners must be crazy, and because the birdies are not detectable without an antenna attached, they are mis-diagnosing what must be a local issue. I'm crazy, but not THAT crazy.

 

[elmocoh]

The fact remains that this internal ticking taints what is otherwise a really neat little radio with many great features. I perceive it as a design flaw. I wonder if Uniden will ever acknowledge this and perhaps offer a solution through a software update, if this is possible. I'm in eastern Massachusetts and monitor two nearby towns, one on 154.2875 NFM and the other on 460.575. The ticking is so prominent it greatly interferes with my ability to monitor them. Another adjacent town is on 483.4375 (these are all fire departments). Here the signal is quite strong but I hear the ticking in the background. Fortunately, of the roughly 200 channels I have programmed, only a handful are affected.

 

[nanZor]

Found the temporary cure for the tick!

If you provide a ground plane for the 125AT on the bnc, the tick will be absolutely GONE! A "rat-tail" will make a small difference, but to really nail it, an even better one is needed.

I was trying out different methods of shielding with foil, when I discovered that when I touched the ground of the bnc connector with it, all noise is gone.

To duplicate - cut a foot wide piece of foil, (not critical) and poke a small hole in the center. Bring this down horizontally over the duck and pinch it real well to make a temporary connection to the bnc base.

NO more clock-pulse anywhere that I can hear, until the foil-pinch comes loose.

The beauty of this test is that it ALSO cured the drifting birdies on VHF Low on my 72 and 95xlt !!!

If this is merely shielding the antenna from the radio beneath, or is just the need for a better ground, I can't say and hopefully would be something Uniden could look into. We've provided enough information for anyone to duplicate.

 

[nanZor]

More testing with the shield

Now that I can make the 125AT's clock pulse go away with the temporary foil shield, I wanted to determine if it is really shielding or just a better ground that is doing the job.

Since this temporary foil shield also cures the vhf low birdie problem on my 72 and 95xlt's, I performed another test to see if it is really just having a better ground. It is pointing to being a better ground than any actual shielding.

Test:
Used the foil sheet to quiet down the 72 and performed a search in vhf-low. No birdies and CHP never sounded so good. Fired up the 95xlt, attached a long whip to it, and brought the antennas of both units together. Not a peep of problems. Then, brought the 95 UNDER the temporary foil shield on the 72, even with a whip attached and in no way could I get the 72 to complain or be bothered by anything going on with the 95 being used as a noise maker.

Seems like trying to force the 95 to bother the 72 either under or over the shield, with cases touching, or antennas touching makes no difference - all is quiet in birdie-land. It really makes it seem like a need for just a better ground, rather than any shielding effect.

The 125 has a slightly different issue, but the same temporary foil ground makes all my raspy clock-pulse birdies go away. My thinking is that like the 72/95 test, shielding is not really the answer, but a good ground would clear things up. Maybe I'll play with trying to improve the grounding with jumpers internally to the 72/95's and if that works, follow up with internal modifications to the 125. I just wish I didn't have to do this in the first place.

 

[DaveIN]

Did you check your BNC ground connection?

 

[nanZor]

Yes, I checked the ground terminals. Although I haven't torn into the 125AT yet, I was impressed at how mechanically and electrically solid (good soldering etc, use of two beefy ground tabs to the board) was on the inexpensive 75/95's.

I also tried testing with a small external antenna - a 2 meter mfj j-pole rollup with about a 4 foot length of coax. On the 125AT, the clock pulsing is gone - totally clean. BUT this was to test the ground, NOT the ability of the J-pole to pick up any external signals!

On the 75/95, the drifting vhf-low band birdies were severely reduced. So I made a common-mode coax choke by using only four, 2-inch turns right at the bnc input to the scanner. CLEAN.

The problem is that the use of any antenna makes one (myself included at first), assume external signals. What I have found here is for 3 different low-end models, it clearly points to an issue being that noise is getting to the antenna via the common-mode ground of the scanner itself.

My eyesight isn't what it used to be, but in the case of the 72/95's, I pulled the boards, tightened all the shield screws, even soldered the shields to the board with some convenient tabs that were just mechanically bent over a big clean ground trace, but no improvement.

The 125AT is still a GREAT conventional scanner, and although I would like the pulses to be gone, I'm lucky that they aren't landing too much on my frequencies of interest mainly in AM airband mode, where I hear the problem worse than on the FM modulated freqs.

Even IF Uniden was to make a hardware change of some sort, would we know about it, unlike software? And as always my thanks to UPMan for being involved - NO manufacturer other then Uniden dares step foot into direct end-user contact like they do. It's one of the reasons I buy Uniden, even though no scanner will ever be perfect.

 

[scannersnstuff]

although the problem is evident/prominent in my bc125at too, it isn't bothersome enough for me to really worry about it. it kind of just remind's me of a faster priority sampling rate. i will say, did the scanner mfg's give up on beta testing these friggin' thing's ?. what ever happened to catching a flaw before releasing the crap to the public ?. i'm surely not going to be walking around with a foot of friggin' aluminum foil hanging off my antenna........no offense whatsoever meant toward's hertzian. now i see that the soon to be released
gre psr-120 has 2 squelch setting's, high and low. there goes the idea of buying that one as a companion to the bc125at. seriously, do any scanner design people actually use scanner's ?. WTH ?.

 

[N8IAA]

I truly was waiting for this scanner to come out. Had put the money aside to purchase. I think I'll wait a little longer. Thought about the 120, but no milair. It just goes to show that the bean counters control how and what is built. The bottom line still drives what is actually produced.
Larry

 

[nanZor]

Found it - it's the display.

I used the 125AT to probe itself and found the display area is what is emitting the clock pulse.

1) Took a 3 foot RG-58 jumper and barreled the oem duck to it. Tuned to one of my problem frequencies 128.375 and opened the squelch to hear the pulse real loud again. Real activity on this frequency would expose the clock, but it's pretty inactive on it now, so I had to open the squelch.

2) Wound a common mode coax choke of about 4 turns around two fingers - clock pulse is gone.

3) Properly choked, I used the Uniden oem duck like a pencil and found the keyboard, speaker, sides and back relatively quiet. When placed anywhere on the display, top of the case, and alongside the bnc shell, the clock pulse jumps right out.

4) Removed jumper and placed oem duck back onto the 125. Took a nearby handheld that had no problem, an Icom T7H, and only when I directly placed it's own duck right on top of the 125's display, top of the case, or bnc shell, the clock pulse now transferred over to the Icom, also tuned to 128.375 with squelch open. Move the Icom 3 inches away, and it is dead quiet. The T7H has an rx-only airband feature.

5) The Icom also told me that no matter what frequency the 125AT is tuned to, it can hear the clock pulse loud and clear with the duck actually touching the 125 display. So even though the 125 seems to only be bothered on specific frequencies, the Icom hears the 125 no matter where you tune the 125. The Icom was left on 128.380 which was actually worse than 128.375.

My only hope is that this testing helps Uniden, and should not be construed as a put-down. I'm only reporting my findings, test-procedures, and VERY limited engineering attempts to describe a problem without any lab equipment.

Even in it's current form, I still really like the 125 (although I wish for more shielding) as the display size, charging / software interface jack (and Uniden software) and onboard serial converter, logic of operations, and the fact that it does civil-air as well as mil-air with some real sensitivity is a big plus. Especially for a 2-battery radio. Impressive. If I heard that an actual hardware change was made, I'd be more than happy to support the effort by purchasing a redundant unit in a heartbeat and keep the original - it is still quite usable.

 

[TedRHayes]

I truly was waiting for this scanner to come out. Had put the money aside to purchase. I think I'll wait a little longer. Thought about the 120, but no milair. It just goes to show that the bean counters control how and what is built. The bottom line still drives what is actually produced.
Larry

Larry, I've use my BC125AT since it was released and can't say I've ever had the issue with interference from the scanner itself in any practical situation. When I use it my home office there are enough other sources (computers, hard-drives, TVs, etc) of interference that I connect it to an external antenna - this seams to eliminate the interference (and extends the reach). When I've used it mobile in my vehicles I generally connect it to an external antenna to extend its reach, but even when I use a rubber duck, I've never had any interference issues. I've used it portable with several different antennas, and it always had good sensitivity from the radio with no interference (other what I get in the environment).

I live in the Dayton, OH, area and use the BC125AT to monitor MILAIR (both VHF and UHF). I can pickup signals from the ranges/MOAs in Indiana, from the MOAs in southern Ohio and over northern Ohio. It scans the channels very fast. In some ways I wish it had more than 10 banks of 50 channels each; I could use a few more to organize my channels more to my liking for different situations.

I find the audio to be much better in the BC125AT than my BCD396T/XT. And my general sense is that it is slightly more sensitive in the Air bands (VHF & UHF) though I haven't performed any extensive tests. Like most scanners, the antenna used (and its location) is very significant!

Just my thoughts.

Ted

 

[nanZor]

although the problem is evident/prominent in my bc125at too, it isn't bothersome enough for me to really worry about it. it kind of just remind's me of a faster priority sampling rate. i will say, did the scanner mfg's give up on beta testing these friggin' thing's ?. what ever happened to catching a flaw before releasing the crap to the public ?. i'm surely not going to be walking around with a foot of friggin' aluminum foil hanging off my antenna........no offense whatsoever meant toward's hertzian.

No offense taken. I'm not going to walk around with foil either.

BUT at least I know the source of the problem now, and not try to go hunting down something external. It is only a problem on a few of my airband target frequencies, but I could see being disappointed if it lands on most of what interests you.

I too like the 125 despite these findings, but had to go overboard to describe it, because like the 72 / 95xlt, everyone tries to point you in the wrong direction as the problem being external - which is a natural assumption until you mention that NONE of your other radios, Uniden included, have the problem under the very same circumstances.

 

[nanZor]

... but even when I use a rubber duck, I've never had any interference issues. I've used it portable with several different antennas, and it always had good sensitivity from the radio with no interference (other what I get in the environment).

This is interesting - you have no issues with the clock pulse, mine are mildly annoying, and another poster has it as being as loud as the target audio. Maybe we are looking at manufacturing differences off the line.

But if we can't come to the conclusion that the display is the area to look at for those of us that have the problem, rather than being something external, no progress will be made.

 

[TedRHayes]

This is interesting - you have no issues with the clock pulse, mine are mildly annoying, and another poster has it as being as loud as the target audio. Maybe we are looking manufacturing process differences off the line.

Just to be more precise. I've never noticed any clock pulse issues when using a rubber duck antenna, though I haven't gone out of my way to listen for it, and most of the time I'm connected to an external antenna,

I did spend a couple of hours earlier this week using the BC125AT with a rubber duck antenna (and earphone) scanning while I was waiting for/watching the launch and fly-by of 20 B-25s from Wright Field, and I don't remember hearing any interference.

 

[scannersnstuff]

i've heard it since day one. i will state that it's worse on some frequencies. i did hear it slightly on uhf today. it's not annoying enough to me, to be that distracting. like i've said before, the thing is a pretty decent little scanner. especially for the pretty reasonable price. i expected slightly better than my pro-84's, and slightly less than my old bc346t. i would have just kept my 346's if they had milair. uniden know's how to play the price game. the jury's still out,but i'll probably still end up getting a gre psr-310.