Icom 7100 issues

[TheRATT]

I bought a used Icom 7100 last month. I installed it in my car.

Up until last week it worked great. I have a Sirio 5000 11/10m antenna (and have an antenna tuner).

On 11m it transmits full power.

On 10m it seems to be about 10 to 15% power.

What did I do??

Thanks!

 

[fourstringburn]

I have the Icom-7000 which predates the 7100 so I can't say all the power settings are the same. On my 7000, the power settings are global for HF 160-10m but 6m has it's own independent power setting as does 2m and 440. If I tune to 11m it stays the same as the HF settings. I assume your 7100 does the same.

For one thing, there aren't many ( if any) antennas that can completely cover the 10 and 11 meter band with a usable SWR under 2:1.

Are you sure the antenna whip didn't move since you used it last?

I suspect you have your antenna tuned within an ideal range for 11 meters and when you go to 10 meters the SWR rises to a point where HAM radio's typically cut back power to protect the finals.

If this is the case and you want to operate fully on both bands, then I suggest getting a Tuner like the 100 watt LDG models.

You can also mark the antenna whip with a sharpie where each band is and move it accordingly when you want to change bands. This of course isn't convenient. but it works.

 

[TheRATT]

I have the Icom-7000 which predates the 7100 so I can't say all the power settings are the same. On my 7000, the power settings are global for HF 160-10m but 6m has it's own independent power setting as does 2m and 440. If I tune to 11m it stays the same as the HF settings. I assume your 7100 does the same.

For one thing, there aren't many ( if any) antennas that can completely cover the 10 and 11 meter band with a usable SWR under 2:1.

Are you sure the antenna whip didn't move since you used it last?

I suspect you have your antenna tuned within an ideal range for 11 meters and when you go to 10 meters the SWR rises to a point where HAM radio's typically cut back power to protect the finals.

If this is the case and you want to operate fully on both bands, then I suggest getting a Tuner like the 100 watt LDG models.

You can also mark the antenna whip with a sharpie where each band is and move it accordingly when you want to change bands. This of course isn't convenient. but it works.

I do have an antenna tuner - and the Sirio 5000 like you said is "close" and I think it'd be close enough with the tuner.

I have had some comments around the net that the 10/11m bands are so close that maybe the tuner isn't happy.

When trying to tune for 10m it takes way longer than tuning for 11. I'll get the SWR meter out and re tune the antenna this week.

Thanks for your thoughtful reply!

 

[fourstringburn]

Why it worked before is a mystery. I missed the part where you said you have a tuner.

Strange why your power level would differ between the 2 bands. Most external tuners have enough tuning range to cover up to an un-tuned SWR of 3:1 or even higher.

What brand and model tuner do you have, Is your a memory auto tuner? A reset would clear all memo tunes then try again.

You could try tuning the antenna for the best match on 10 meters and bypass the tuner assuming it has a bypass switch) and just use the tuner for 11 meters.

 

[TheRATT]

Why it worked before is a mystery. I missed the part where you said you have a tuner.

Strange why your power level would differ between the 2 bands. Most external tuners have enough tuning range to cover up to an un-tuned SWR of 3:1 or even higher.

What brand and model tuner do you have, Is your a memory auto tuner? A reset would clear all memo tunes then try again.

You could try tuning the antenna for the best match on 10 meters and bypass the tuner assuming it has a bypass switch) and just use the tuner for 11 meters.

Ah, I have a LDG-Z-100A-DXE.

I checked the manual and there is no explicit reset - is this just an unplug it from power to reset thing?

 

[9C1Driver]

Get an antenna analyzer and see what’s up.

 

[TheRATT]

Get an antenna analyzer and see what’s up.

I'm going to go over the whole antenna system again. I found that I can reset the antenna tuner by just unplugging power for five seconds. Easy enough!