bigcam406
Member
ive had mine a few months,have used various antennas,havnt heard any ticks during any transmissions.im listening to air freqs and 140-142 mhz local stuff in my area.could location have anything to do with this problem?
BC125AT Post Release Thread
- Thread starter DaveIN
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I think like everyone, the 125AT is a fantastic value, but at least for my unit, things could be better. Seems like some have the problem, and some don't.
If you want to be sure just do this test:
* Tune ANOTHER radio/scanner to 128.375, 128.380, or 128.3833 AM. There are other troublesome frequencies, but this is one of the biggies for me. For today's test, I used my 396XT to drag across the 125. On the 125, use either no antenna at all, or just a rubber-duck - oem or anything. Don't use an external antenna as the extra ground of the braid shield will skew the results.
* Bring the other radio's antenna across the display of the 125AT. You may have to open the squelch. You will hear the clock driver or whatever is driving the 125 display in your other radio.
On this frequency, the noise is mildly annoying when an aircraft signal strength on the 125 is strong 4-5 bars. At 2-3 bars, the noise is bad enough to make me want to lock it out. And at the noise floor of 0-1 bars, lock-out is mandatory as the pulse-noise is too much to bear. This is just one example. Fortunately, my 125 isn't totally riddled with it.
As with the temporary foil test, and when attaching coaxial jumpers, the additional grounding material either stops the display noise completely or reduces it greatly. A simple coaxial choke coil clears it up completely.
Anyway, I've gone waaay too long on this issue so I think I'll drop it and give everyone a well-deserved break.
If you want to be sure just do this test:
* Tune ANOTHER radio/scanner to 128.375, 128.380, or 128.3833 AM. There are other troublesome frequencies, but this is one of the biggies for me. For today's test, I used my 396XT to drag across the 125. On the 125, use either no antenna at all, or just a rubber-duck - oem or anything. Don't use an external antenna as the extra ground of the braid shield will skew the results.
* Bring the other radio's antenna across the display of the 125AT. You may have to open the squelch. You will hear the clock driver or whatever is driving the 125 display in your other radio.
On this frequency, the noise is mildly annoying when an aircraft signal strength on the 125 is strong 4-5 bars. At 2-3 bars, the noise is bad enough to make me want to lock it out. And at the noise floor of 0-1 bars, lock-out is mandatory as the pulse-noise is too much to bear. This is just one example. Fortunately, my 125 isn't totally riddled with it.
As with the temporary foil test, and when attaching coaxial jumpers, the additional grounding material either stops the display noise completely or reduces it greatly. A simple coaxial choke coil clears it up completely.
Anyway, I've gone waaay too long on this issue so I think I'll drop it and give everyone a well-deserved break.
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bigcam406
Member
all of us here appreciate your efforts.without tech savy hobbyists like yourself,we wouldnt have known what the problem was.its strange that its only happening on a few though.
Are these the only frequencies and mode you see this problem on? If there are other frequencies/modes, could you list them so we can see if our radios also experience this problem?
And what value of choke coil are you using? Is this a custom random length wound choke or something off the shelf?
If it's a real problem for some, maybe you have an answer. Don't forget to include it in the Wiki entry.
Sure. The environment is a stock 125AT with the supplied oem duck attached. Without any duck, or with an external antenna attached on a long transmission line, the test will be invalid. Other receivers with some spare uniden ducks are the control units that don't exhibit the same issue. The freqs that the 125 can hear itself on follow..
For VHF airband, the three that will break squelch when set to just above the threshold are: 120.000 / 123.050 / 128.375
With squelch open, the rhythmic pulsing can be heard on
120.7666 / 121.525 / 122.2833 / 124.1916 / 124.575 / 125.3416 / 126.100 / 126.8583 / 128.000 / 129.9083 / 131.425 / 133.7166 / 134.475 / 135.2416 /136.7666.
I started on milair but gave up after three 225.150 / 227.425 / 228.950. Thought I'd spare my encoder after that.
Fortunately I don't have anything programmed for those weaker frequencies that don't break the squelch. Even so, if signals are strong, it would cover it up. Weak signals, or on frequencies where the clock is strongest, the pulse is annoying when communications come up.
It is just 4 turns of an RG-58 jumper wound tightly together in a 2-inch radius just above the bnc. The jumper was three feet long barelled to the oem duck. Alternately, I tried #43 mix snap-on ferrites which also did the trick, but the coaxial choke was sufficient.
I'm hesitant to do anything in the Wiki, because I'd really hate to have anyone make a knee-jerk decision as there is no accounting for the fact that I may have a one-off unit problem, an early board version, or just the fact that given the value of the entire package, this issue is something I can live with on a handful of frequencies. At the end of the day, the 125 is a GREAT conventional scanner, especially for the airband fan that wants both great civil and milair coverage in a modernized package. Maybe Uniden could tweak it a little and make a great scanner even better.
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New firmware released.
http://forums.radioreference.com/un...5at-firmware-update-released.html#post1745776
http://forums.radioreference.com/un...5at-firmware-update-released.html#post1745776
TedRHayes
Member
"deaf" issue resolved in new firmware
Since the new firmware has been released to the public, I can now widely report that the issue with the BC125AT going "deaf" which I reported in earlier posts seems to be fixed by this latest firmware release. Have been running this update for couple of weeks and have not seen the issue at all.
Thanks for your support UPMan.
Since the new firmware has been released to the public, I can now widely report that the issue with the BC125AT going "deaf" which I reported in earlier posts seems to be fixed by this latest firmware release. Have been running this update for couple of weeks and have not seen the issue at all.
Thanks for your support UPMan.
Since this radio has been out for awhile and we have a new firmware update
out for it I am gonna close this thread and un-sticky it.
Please continue discussions in the firmware update thread.
Thanks!
Marshall KE4ZNR
out for it I am gonna close this thread and un-sticky it.
Please continue discussions in the firmware update thread.
Thanks!
Marshall KE4ZNR
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