GTX HT Tx audio "motorboating" problem

This forum is for the discussions targeted at converting various models of Motorola equipment to operate in the 900MHz Amateur Band.

Moderator: Queue Moderator

Post Reply
kj6vu
Posts: 14
Joined: Fri Mar 01, 2002 4:00 pm

GTX HT Tx audio "motorboating" problem

Post by kj6vu »

I have programmed up 3 GTX portables. They all work just fine except that two of them transmit a low level popping sound that I can best describe as "motorboating". Looking at the service monitor, it looks like there are very low deviation spikes on the carrier, maybe in the PL encode signal. Has anyone else seen this? Maybe I have accidently programmed the radio in some kind of lame configuration.
Thanks
George
User avatar
kcbooboo
Batboard $upporter
Posts: 2117
Joined: Wed May 01, 2002 9:03 am

Post by kcbooboo »

Not exactly, but I have seen low / bad batteries cause that on other radios. See if swapping batteries has any effect.

Also, the GTX deviation adjustments allow you to balance the low and high frequency values. These could be way off. Check them out. The balance should be near the center of its range; the overall deviation about 3/4 of the way up.

All of the GTX 900 MHz radios I've touched had low deviation, around 1.75 kHz. I've bumped them all up to 2.5 since, in my area, we're using a 5 kHz-wide MaxTrac as a repeater receiver.

Bob M.
SlimBob
Posts: 911
Joined: Thu Dec 18, 2003 11:38 am

Post by SlimBob »

Hrm. One of my portables is doing this too. I will check it out.
W1IMD
Posts: 10
Joined: Wed May 28, 2003 4:28 pm

GTX Portables motorboating on transmit

Post by W1IMD »

I bought a GTX handheld at Dayton last year and mine did the same. I found that if I squeezed the case just righ the noise went away. Taking the radio apart I found one of the metal shields was loose, I think it was the one over the keypad. Radio plays fine now. good luck
SlimBob
Posts: 911
Joined: Thu Dec 18, 2003 11:38 am

Post by SlimBob »

I thought I'd replied already but I guess I haven't. My motorboating problem doesn't follow the battery. It's one radio specific.
Post Reply

Return to “Converting Motorola Equipment to 900MHz Amateur”