strange XTL5000 problem

[toyradios]

Hi all - got a strange problem with a remote mount UHF XTL5000 mobile with an A5 style control head.

During the initial powered up, the radio stays keyed for about 5 seconds, than drops off and emits a constant tone . . . almost like the channel is unprogrammed.

The radio dies when trying to transmit . . . .behaving similar to a low voltage input.

I measured the voltage and it is a constant 13.8 - 14vdc.

I can read/write to the radio without issue.

Has anyone encountered a similar problem?

Thanks
Bill

[Jim202]

Hi all - got a strange problem with a remote mount UHF XTL5000 mobile with an A5 style control head.

During the initial powered up, the radio stays keyed for about 5 seconds, than drops off and emits a constant tone . . . almost like the channel is unprogrammed.

The radio dies when trying to transmit . . . .behaving similar to a low voltage input.

I measured the voltage and it is a constant 13.8 - 14vdc.

I can read/write to the radio without issue.

Has anyone encountered a similar problem?

Thanks
Bill

Has this radio worked before, or is this a new install problem? You didn't say if this was a high power or a mid power radio.

You might want to verify that there is a jumper from the emergency pin on the accessory connector to ground. My first suggestion would be to check and see if the jumper is missing. Strange things can happen if it isn't there depending on the way the radio is programmed.

Where did you measure the voltage as being good? You need to do it on the radio side of all fuses and splices. Fuse holders and splices have been known to make poor connections given enough time and moisture.

Jim

[toyradios]

Yes, this radio worked before.

Its a high-power chassis.

Can you provide more information about the jumper from the emergency pin.

Voltage was measured at the 12VDC distribution buss.

[Will]

" with an A5 style control head."
Bill

[techtonics]

how much power is being output before the drop off? I wonder if one of the finals is bad causing it to fail. Also, check FSB10516

[Jim202]

Yes, this radio worked before.

Its a high-power chassis.

Can you provide more information about the jumper from the emergency pin.

Voltage was measured at the 12VDC distribution buss.

You need to measure the voltage at the radio. Like I said, poor splices and a fuse connection gone bad can cause all sorts of strange problems.

Will is asking about the A5 head. Don't think the XTL ever had an option for that head. Maybe a W5 or W7 if this is an older radio.

On the high power radios, they generally didn't require the emergency jumper unless someone played with the software and set the emergency on. If you need the information on the connections, it is in the manuals for the radio. They are available for download on the MOL site.

Jim

[desperado]

One possibility is that you have two issues. First being the emergency wire, or it's a trunked radio and it's trying to get on a system.
This coupled with a bad antenna will cause an XTL to shutdown or act funny.

We ran into something similar with some fed radios that were in UC vehicles with glass mount antenna's.
If you keyed the radio, it would reboot, scream, or somehow complain. The antennas would check ok with an analyzer, but with 100 watts to them the SWR would skyrocket and RF would get into the
radio, and control head and make it all sorts of mad.

If it's a trunked radio try putting it on a conventional channel at power on and see if it calms down, or try a dummy load on the antenna port.

[toyradios]

Update to the post.

After trying everything I can think of, I sent the radio back to Motorola for repair.

The radio returned 5 days later with a note on the service ticket that said the main board was replaced.

Thanks for all those that took the time to read my post.

Bill

[com501]

FYI, you should NEVER run a 100watt radio of any kind into a glass mount antenna.

IS it actually transmitting at power up or is it just a red led? Next time you get these issues this and what is below are things to consider:

The boop indicates it didn't like something. Hard to say without looking at the codeplug, but the EMER TX will keep trying, unless the radio is programmed as a trunked radio, and if it can't see the system (or there isn't one) if will fail the EMER, boop but will also display OUT OF RANGE. LIke was stated previously, you also need to make sure you meaure voltages AT THE RADIO while keyed. Anything else is just a guess.