Low Power Output


Steve Alborn
 

I'm afraid I already know the answer to this, but possibly someone
knows something about it that I don't.

I have had my IC-7000 for two years. I've found recently that my
output, even set at 100%, is way down on the lower frequencies. This
check is into a dummy load in the CW mode. The measurements are:

10 meters - 100 watts 20 meters - 60 watts
12 meters - 90 watts 30 meters - 40 watts
15 meters - 75 watts 40 meters - 15 watts
17 meters - 65-70 watts 80 meters - 8 watts
160 meters - 2 watts

My antenna that I normally use is a 90 foot long inverted vee, fed
with 450 ohm line, with a home brew tuner with dual roller inductors.
40 on up are my favorite bands; I've never worked 160, and 80 only
once. One of the inductors has become intermittent and opens up
sometimes when tuning. I always use an MFJ-259 analyzer to tune;
never the rig, and that's how I discovered this. I may have
transmitted when it opened up without knowing it. So, I fear the
finals are going. It's interesting, though, that I still have full
output on 10 meters. If I'm not mistaken it's usually the HIGH
frequencies that go first.

I have no VHF antennas or any measuring equipment for VHF, so I
haven't tried the Ant. 2 output.

I also performed the CPU power up reset to no avail.

Just for grins, I measured Ant.1 center conductor to ground. It is
99.1k ohms if that means anything significant.

How much will sending it in cost me? Has anyone changed their own
finals, or is that a can of worms? Any ideas are appreciated.

73's,
Steve
KE6PY


DON
 

I have recently found the same problem of low power output on HF. In my case, about 65 watts on the HF bands as measured by the internal meter and an external meter into a dummy load. Test was run in modes CW, RTTY and FM. Also tried the CPU reset with no change in output.

Additional info: Lower output power occured after an unexpected complete power down of the rig during a 40 mtr SSB contact. I turned the rig back on, and as soon as I started talking, the rig powered off again. I manually lowered the power to 50% and was able to complete the contact. Yes, the power was adjusted back to 100%. The unexpected power down has not occured again since my maximum power output is now about 65 watts. Power supply is a 30 amp MFJ. Meters indicate 13.8 V and under transmit conditions 15 amps.

Any suggestions?


Link McGarity <wv4i@...>
 

Sounds to me like you have either a bad pwr cable connection or a pwr supply issue. If a switching ps, possible that RFI could cause this problem but unlikely. I assume you're getting 65W max into a known 1:1 SWR to a 50 ohm resistive dummy load. Assuming all the latter, and it shuts down above 65W, I would definitely check with a different PS and pwr cable. The pwr cable is a bit tough to get in/out of radio connector and could be hanging by a couple strands somewhere, thus the amp/pwr out limit apparently being demonstrated. I would not condemn the radio until everything else checks out. Rgds, Link, WV4I....


nokia_guru
 

Hi Steve,

I don't know if you've solved your low power issue yet, but just to let you know...

I've just re-built my station at home after using the 7000 at the EARS picnic. When I was checking everything out, I was only getting about 65W out on all of the HF bands (into a dummy-load).

After reading the various posts here, I checked the PSU (Alinco DM330MV), and found that I'd accidentally turned off the preset switch for 13.8V.

However, the meter on the front panel still indicated that it was 13.8V, but I didn't measure it. When I switched the preset back on, The power went back up to around 98W!

Just for laughs, I checked the oxidisation on the fuse terminals as some others had suggested, and lo-and-behold - mine were all grey & tarnished too.

After cleaning them - I now have 110W across the bands... Yeah!

Thanks for all the good suggestions guys.

Steve - If you read this message in the near future, give us a call about your 7000. Also, I have some good news about the Cal QSO party.

Cheers,
Steve (W6TAN/GoTAN).


--- In ic7000@..., "Steve Alborn" <scalborn@...> wrote:

I'm afraid I already know the answer to this, but possibly someone
knows something about it that I don't.

I have had my IC-7000 for two years. I've found recently that my
output, even set at 100%, is way down on the lower frequencies. This
check is into a dummy load in the CW mode. The measurements are:

10 meters - 100 watts 20 meters - 60 watts
12 meters - 90 watts 30 meters - 40 watts
15 meters - 75 watts 40 meters - 15 watts
17 meters - 65-70 watts 80 meters - 8 watts
160 meters - 2 watts

<snip />