Sunday, December 2, 2012

ICOM IC-7000 Low Power Output RESOLVED!

I've recently been using my Icom IC-7000 inside my house as a convenient way to listen to W1AW Morse Code practice sessions.  One afternoon, I was on 40 meters and decided to have a QSO with a fellow ham. I went to key and noticed that my power output level was peaking around 60 watts +/- or so.  Since I had the power output set at 100% (or 100 watts), I was concerned.  I knew that my antenna was good, the auto tuner had been successfully initiated and was operational.

Hmm, had I managed to break something?  Time to search the Internet for help!

It would seem that I'm not the only person who has had this issue.  The first answer was very common, something along the lines of:  "The IC-7000 needs 13.8 volts; anything less will affect power output."  I was already familiar with that problem - mostly due to my operation in my vehicle.  The IC-7000 worked great when the car was running, but when the car was stopped (engine not running), power output > 50 watts caused the unit to cycle off and back on.  Apparently, the solution for that problem is a "voltage booster."

On to the next "most likely" cause - bad fuses.  Really?  Bad fuses; corrosion?  Well, guess what - yep, that was actually the problem.  I found a good article by AB4OJ - Link Here -> Check out the heading "Low Power Output on Transmit."

I checked the 30 Amp ATC fuses and take a look:
IC-7000 30 Amp ATC Fuses
Notice the nice dark corrosion line across them?  Yeah, I noticed them also.  I took a pocket knife and scratched some of the oxidation off the fuses, put the back in the fuse holders and yep, the IC-7000 went back to transmitting all of 100 watts.

Next step:  get out my dremel and buff the oxidation off the fuses.

73 de KJ4WLH

3 comments:

  1. Had same problem with my IC 7600. I went one step further after cleaning the blades of the fuses I applied solder to both sides of fuse blades increasing the thickness of the blades. Fits much better into the fuse holder and will most likely keep the problem for rising again.

    LR W8MIS

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  2. LOL, I had about 50 watts. I read your post pulled my fuses and took a pink eraser to them and now I'm at 75 watts (swr 1.5).

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  3. Hi All,

    I've had this problem too, high resistance fuse contacts dropping power by ~50%. HOWEVER, if that doesn't fix it, read on.

    I just received my IC7000 back from Icom Repair in St. Joseph, MI (Tech named Matt, very conscientious and communicative). The rig was making less power output on bands below 15m, dropping down to 10 watts on 160m. Cause given was leaky Power FETs needing replacement. I asked Matt what is likely cause of failure, and was told: 'most likely auto-tuner'. Well, I'm guilty as charged. I do use an auto-tuner (SGC MAC200). I replied that I -try- to remember to reduce power when tuning, and Matt advised that may not be good enough to avoid the problem, as momentary high VSWRs can cause a high reflected -voltage- that can damage those transistors. Makes sense ! So $250 (plus outbound shipping ~$25) and 3 weeks later, the IC7000 is back to its good old 100 watts on all HF bands (provided it has ~13.8vdc supply, at 12 volts it'll do around 50w). From now on I'll be tuning the auto-tuner at lowest output of 1%, which shows 2-4 watts on the Bird. 73, N8CVW

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