JT1000 TX Noise

Rayjk110 · Post by **Rayjk110** » Sat Jun 03, 2006 5:20 pm

Hello. On my recently aquired VHF JT1000, when I TX on it (With or without spkr/mic), there is a real fast, but faint 'popping noise'. It happens all the time, and it's in an even pattern. Kinda like real quiet 'clicks', mebey at a rate of 4 per/second.

Any idea as to what it is?

It kinda seems to go away if I hold the antenna or bend it a little

K8TEK · Post by **K8TEK** » Sat Jun 03, 2006 5:23 pm

Are you Transmitting DPL, because that is what it sounds like you are describing,

Rayjk110 · Post by **Rayjk110** » Sat Jun 03, 2006 5:28 pm

No, PL and DPL. It's definately not something with the tone, Tim, I know the radio needs a new front housing because of the display, but even a speaker mic will do it.

Just really quiet, but fast click noises.

Will · Post by **Will** » Sun Jun 04, 2006 12:33 am

" It kinda seems to go away if I hold the antenna or bend it a little"

Could be an incorrect antenna for the freqs you are using. I have seen them do that with a poor antenna.

Rayjk110 · Post by **Rayjk110** » Sun Jun 04, 2006 6:25 am

It is a VHF Radio, on a VHF antenna, using frequencies in both the 151.xx range and ham band. It does have a bend to it and a crack in the plastic, however, I can hit repeaters with it OK.

It is a "black dot" antenna.

MTS2000des · Post by **MTS2000des** » Sun Jun 04, 2006 10:47 am

sounds like a shielding issue, there was an SRN a while back with a retrofit kit that added an improved front shield, flex and such parts...I've heard it referred to as the "Jedi noise kit".

I am sure someone on here can recall the SRN number.

Rayjk110 · Post by **Rayjk110** » Sun Jun 04, 2006 11:05 am

Hmm, I thought that was for the 'windy' noise in Jedi TX, which I am aware of, but this is different, just really fast paced clicks, but quiet. Nothing I've heard before on a Jedi, though. I'll look into the Jedi noise kit. Thanks.

Rayjk110 · Post by **Rayjk110** » Sun Jun 04, 2006 2:32 pm

Actually, come to think of it, it kinda sounds like a current ripple, but it happens with both my JBro and Moto batt's, and I know it's not the housing, I TX'd with the front case off (obviously no audio would come thru), and it was still there, but not as loud. Listening on our local PD's UHF Repeater, some of their portables (HT1000 and MT2000) have the same problem. I don't have another VHF antenna to test it with, though.

Rayjk110 · Post by **Rayjk110** » Sun Jun 04, 2006 6:40 pm

I should also add that this noise doesn't occur when transmitting in "Test Mode" on the frequencies there, which makes it even more weird.

Al · Post by Al » Sun Jun 04, 2006 7:26 pm

I don't remember whether or not there's a DPL preprogrammed when the radio is in test mode. If there isn't, and you see this clicking noise only on tx DPL-programmed frequencies the compensation circuitry ahead of the tx vco may be way out of alignment.

Rayjk110 · Post by **Rayjk110** » Sun Jun 04, 2006 7:33 pm

Well, when in FPP mode in regular operation, I tested a frequency on CSQ, TPL, and DPL, and all had the clicky noise. I went to test mode (it will go thru CSQ, TPL and DPL) and it wasn't there.

SPEAKER MIC · Post by **SPEAKER MIC** » Sun Jun 04, 2006 8:19 pm

let me go through my notes, i had a ht1000 and mts2000[uhf] that did the same thing..

for starters,
make sure the antenna lug is secure, check the tightness of the coupling flex for the logic and tx boards and then check the tab that connects the antenna and tx board [i cant see the condition of your radio, but i always do that when i get a beat up one]

most important!!

if it has the switch to swap between external and internal antenna, look at it real good to see if one of the tabs is worn down..[ thats always given me trouble for radios used with the p/s mics and mtva's..

good luck

john

kd6rfs · Post by **kd6rfs** » Mon Jun 05, 2006 10:32 am

Hi....I have a VHF Jt1000....and mine is in perfect condition....and it does it too....from what I know it is normal, its processor noise on the transmitted audio....I read about it on a JT1000 article review on the net....it should be barely audible.....so, I dont know if thats what you have....but I know its one of the slight complaints of the JT1000, and probably other jedi radios....it doesnt bother me, I cant hardly even hear it....so if yours is pretty loud, then it must be something else....hope this helps....David KD6RFS

Rayjk110 · Post by **Rayjk110** » Mon Jun 05, 2006 2:37 pm

Yeah, it's barely audible, except if I use AGC it kinda amplifies it, but just a constant, quiet, clicking noise.

I still don't know why I can't hear it when in Test Mode TX frequencies, mebey the processor isn't as active to create it?

Thanks
ray.