xtl5000 interference problem

[BENWSI]

We have recently started swapping out handheld control Spectra trunk mounts for newer handheld control xtl5000 trunk mounts for one of our customers. The vehicles are equipped with a Stico Euro style disguise antenna. The Spectra never had any problems, but the xtl5000 is getting into the Fed. Sig. siren system. Also, the radio occasionally resets when you try to TX. We did three of these when we realized we had a problem. We thought maybe an antenna problem, but all three have the same antenna. We did test the radio successfully with a dumby load and a VHF 1/4 wave mag mount. The only way we can get the radio to operate properly, (with the Stico,) is to scale the power back from 110 watts to 5o watts, which is unacceptable to the customer.

Any thoughts or suggestions?

Thanks,
Ben

[/\/\otobrola]

Ben...check the reflected power on the Stico(s)...and/or try a totally different radio w/ low power...and check it again.
Sounds like the rf deck doesnt like the load presented by the antenna/groundplane combo.

[Bill_G]

Did you reuse the existing coax cable leaving it intact, cut it to length for the new install, or replace the line?

Just for s&g's add about six feet to the line. At least determine if putting your wattmeter in line fixes the problem.

Look for the VHF tuning stub, and see if it needs to be cut / lengthened.

[Jim202]

What is the rated power for the StiCo antenna? Some of their antennas won't take the full 100 watts
that people want to jam into them. They are made for less power. Might want to double check the
antenna specs.

Jim

[BENWSI]

This has been wierd. We, as I said, eliminated the Sti-co with a 1/4 wave and it seemed to work on one vehicle but not the others. The first vehicle had to have the Fed Sig siren box moved out of the trunk away from the xtl5000. That eliminated most of the problems. All three vehicles had working 100w Spectras that did not interfere with the siren, but the xtl seems to be the fly in the ointment.

You guys keep a heads up on this one, there is a case started up at Motorola to investigate the apparent rf interference problem associated with xtl5000's.

Ben

[woody503]

Our agency had the same issue with the 2010 chargers and the euro mount. When you key the radio it would shut off and reset. Tracked it down to the encryption chip in the radios, 2500 and 5000. Moto replaced the chip DES-OFB AES and the radio worked fine at 110 watts. It took a couple of weeks to figure it out. The sti-co antennas and radio are working great.

[thomsoningreen]

Question you stated above that your using a Federal siren system. Are you trying to have the radio go out over the siren for external radio? If so the motorola's weren't designed to play well with other siren systems. I have had nothing but trouble in the past with that. I have had is cause random errors.

[resqguy911]

Question you stated above that your using a Federal siren system. Are you trying to have the radio go out over the siren for external radio? If so the motorola's weren't designed to play well with other siren systems. I have had nothing but trouble in the past with that. I have had is cause random errors.

MCS2000s work with Unitrols and XTL5000s work with SmartSirens. They play just fine if configured properly. There has to be something else afoot.

[diogini]

Try running the main power for the radio directly to the ground and power lines of the vehicle battery. The Siren amplifier should than use a different ground, (i.e. seat belt bolt and) and run a power line from the battery to the rear of vehicle, trunk, to a fuse block, which will feed other equipment you have installed. The siren amplifier connects to that fuse block. This isolates the radio completely from the other equipment. Had similar problem with the 80K amplifier and this seemed to solve the problem.

[diogini]

Actually instead of wiring the radio direct to battery wire the Siren Amplifier direct to battery. This is what was said by Unitrol when I discussed the issue I had with the 80K amplifier causing problems with the radio.