Alc overshoot spike remedy icom 7300

[@santo1953]

Thanks for these useful indications, I'll try to put it into practice on my 7300 as I have this annoying problem with an LDMOS amplifier. Did you use a 500 ohm or 500 K okm potentiometer? Thank you very much !

[@wildbill1]

500k ohm

[@santo1953]

@@wildbill1 Thanks, I can tell you how it works with my RF Power HVLA1K3 amplifier. 73Santo Ik1JTP

[@AD4C]

@@wildbill1 I have read some guys complaining about the 7300 overshot, I have one for 3 years now and been using LDMOS amps with it, first a single LDMOS, now two LDMOS and never have had any issue with it, I am using the ALC cable between radio and amp and with just 30W in I have 1500W out but the amp alarm never has triggered or sound for excessive sudden input power.

[@wildbill1]

@@AD4C Yeah I have the Acom 1000 amplifier and it does not have a separate ALC plug-in unfortunately. So when the 7300 spikes up beyond 100 W it triggers the amp to go into standby mode. The simple mod works well to prevent that. Just needs a very small amount of DC voltage applied to the ALC input of the radio

[@AD4C]

@@wildbill1 get rid of that Acom and buy the one I have, a Mercury Lux.

[@GreatLakesReliance]

Great Video

[@madman2594]

So where do I plug it into radio or the amp

[@billluddington3309]

Alc port in the back of radio

[@billluddington3309]

Alc port in back of radio

[@AD4C]

You forgot what everybody was waiting. The electronic circuit diagram of how the pot, cables, battery and conectors are wired. Your explanation is ok but left everyone wondering.

[@wildbill1]

We used cheap radio shack plastic project boxes and 500k ohm pot.We used 9 volt batterys. These things take 10 minutes to build. Remember that you are applying NEGATIVE voltage to the ALC jack on the Icom. The Center pin of the RCA is the negative lead and the outside of the RCA gets the positive lead. You set the RF power full up. Then adjust the carrier using the pot on your new alc box. I chose 25 watts. Now you can turn up your audio and the radio never pulls back the power. The audio doubles out of the rig. I can hit 100% mod now now problem from 25 watts. Pretty cool little project and no need to open radio up.

[@wildbill1]

Edit:Conduit box not radio shack