Radio Emergency

[Tinman590]

My stepdad has a Galaxy 949 with a power supply hooked to it and a imax2000. Today he called frantic saying it wont key up all the way even to get a swr reading. I turned my base on and could barely hear him on it about 1 s unit Normally a 7 or 8. I told him probably the coax. thought id see what yall thought. No amp either by the way

[Tinman590]

mystery problem huh?

[PONY EXPRESS]

1st thing to do is see how his radio is receiving stations he normally listens too. This will eliminate the coax and antenna if it receiving aok .
If its hearing normal then its the radios transmit section maybe a transistor etc OR take your radio over there with a swr meter and check SWRs.

[coondog]

with not even being able to get a swr reading is his DK and Swing where its suppose to be?

['Doc]

Just too many possibilities to make a guess about without knowing a lot more. The best advice I've seen so far is to go check things out yourself. Try the substitution thingy till you find something obviously wrong, then you can try to figure out what's wrong with that thingy.
It's a fairly good idea to check the simple things first, as in is everything connected correctly, not loose? Rule out the 'easy' things first. If you're in the middle of it, sometimes that forest is a hard thing to see for all them @#$ trees. 'Think' your way through it. Continue till you get totally lost. Have a beer, then do it again to see what you didn't see the first time. Sound familiar?
- 'Doc

(Tell me I don't know how to give cheap advice!)

[Tinman590]

Just too many possibilities to make a guess about without knowing a lot more. The best advice I've seen so far is to go check things out yourself. Try the substitution thingy till you find something obviously wrong, then you can try to figure out what's wrong with that thingy.
It's a fairly good idea to check the simple things first, as in is everything connected correctly, not loose? Rule out the 'easy' things first. If you're in the middle of it, sometimes that forest is a hard thing to see for all them @#$ trees. 'Think' your way through it. Continue till you get totally lost. Have a beer, then do it again to see what you didn't see the first time. Sound familiar?
- 'Doc

(Tell me I don't know how to give cheap advice!)

Good advice as usual Doc, I think i will have a beer before I even begin this weekend i will check it out for him and let yall know.

[Lonestar]

The transmitter's protection circuitry could be throttling back output because of a bad mismatch in the antenna system.

As Pony Express said, see how well the rig receives; but sometimes even this may not indicate a problem with the coax or antenna, save for a partial or complete short circuit. Try the Galaxy with a known good antenna; conversely, try a known good radio with the Imax 2000. Even better if you have/have access to one, is an antenna analyzer such as the MFJ-259/-259B.

If the Galaxy does well on another antenna, then check out the stepdad's setup. Does his feedline run through an attic or crawlspace where some errant critter may have munched on it? Could it have been pinched in a door or window opening? How are the connectors? You may have to take the Imax down to get a good look that that end of things; this will also give the opportunity to check hardware, weathering, etc, maybe even install a groundplane kit [see link below] if not already equipped.

Worst case is that the Imax could be internally damaged, if run with high power [if not physically, as from high winds or a storm]. Like its Antron 99 cousin, it has tuned-transconductance matching, and pumping too much juice to it might cause trouble. See [Please login or register to view this link] for a dissection of the antenna.

[I get long-winded when I'm up too late and overtired... [ external image ]]

[Tinman590]

ok I checked it out the radio will not dead key but will modulate to like 4 watts its like sideband sort of when i key up there is no frequency on my counter but I can still talk very weak. Radio was doing a 3.5 watt dead with 25 watts of swing.

[MysteryMan]

I am assuming that it is hearing just fine correct?

It sounds like the finales let the smoke out. Once you get it fixed you better check the SWR fwd & rev power. Finales usually don't fry, something causes it.