MicroTrak-RTG FA question

Anyone know how much VSWR the MicroTrak-RTG FA can handle before it gives up the ghost?

I just wanting to be sure before I go traking with my J-Pole in the wingtip.

All of Pete's install pics are now broken links so I am not sure I have mine installed in the best arrangement with the other devices in my wingtip.

I have an antenna analyzer and can see that the end rib does affect the resonate freq. of the J-pole.

Since so many have gone before, any fear of swamping the MicroTrak-RTG box if it is installed near the J-pole?

How about the Byonics GPS puck?

Can't wait to get the call sign so I can give it a go.

Copied from the Yahoo Group:

"Re: [MicroTrak] MicroTrak-RTG FA

The amplifier module is rated to have a maximum mismatch of 20:1 at 8 Watts output. But this applies only to the final amplifier. In actual practice, with a poor mismatch, the SWR causes RF to "swamp" the PIC, which can cause continual resetting, leading to eventual meltdown of the amp or other parts of the system. If you try to operate the RTG FA with a rubber duck antenna at more than a couple hundred milliwatts, you could induce the continuous reset ( Note: don't do this!) but with low power it could go on transmitting aborted "blips" (short bursts of carrier only or partial packets) until the cows come home, or the battery dies. (Safety tip: hams will hunt you down and kill you if you jam the national APRS channel with 100 ms blips every three seconds)

Damage to the amplifier from poor SWR is far less common than failures arising from high static or RF fields. The RTG FA has a bleeder resistor to help prevent static from blowing out the MOSFET amplifier, but extreme atmospheric phenomenon can exceed the bleeder's protection limits.( very rare) Having a very high radiating power antenna from another transmitter in the near field of the RTG antenna is far more likely to kill the amplifier. Even if the amp is dead, the unit is not generally "de-ghosted" ; there is life in there still yet, although it will require a new amplifier ( not a big deal) and possibly reloading the firmware and configuration to the PIC if it felt particularly abused. The MOSFET amps have two states: Good, and Bad. A bad amp won't result in less power output, generally; It will just result in no output ( Note that you will still be able to hear the exciter transmitting into the amplifier from close range) If you have low power out, the problem is more likely in the DC input circuitry. This can include blown Voltage Regulators or exploded Steering diodes. This would be caused by input voltage spikes or just plain old over voltage.

Was that a ridiculously over-complicated response to a simple question? If so, ignore all but the first sentence!

Allen AF6OF
VHS"

pics!!!

https://picasaweb.google.com/105642906823049349759/Tracker#