Bouncing Meters on IC-7300

[Harry Mueller]

Hello!

I’m trying to troubleshoot a few days of odd behavior on my IC-7300. When transmitting phone I am seeing the S/Po meter, ALS, Id, and SWR meters all rising and falling with my voice (the video is me broadcasting 100 watts into a dummy load, not all the meters bounce into the dummy load). I have tried some troubleshooting steps which have not really gotten me anywhere.

1. Changed mics
2. Tried different modes, SSB and FM showed the same behavior, AM less so and none noted on any of the digital modes
3. Tried different antennas
4. Changed coax
5. Checked my ground
6. Reset the radio to factory settings
7. Compared with an IC-7100 which does not exhibit the same behavior with the same settings

I know not all of these steps were likely to be the problem but I wanted to eliminate as many variables as possible.

I feel like I’m missing something obvious. Does anyone know what I’ve missed?

–Harry, W1HMM

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[Fred Kemmerer]

Hello Harry,

From your video, it looks like the IC-7300 is in SSB (LSB) mode. This is correct for the phone section of the 40m Band where you are testing. It’s normal for the Power, SWR and many of the other meters to bounce up and down with the level of your voice. If you run the rig in FM or AM mode into a dummy load, you should see a constant level as long as you are transmitting using PTT down.

Beyond the meters, are you having other problems getting your signal on the air? How about during receive, if you connect an antenna and tune update and down the range of 7 MHz to 7.3 MHz (the 40m band), do you hear any stations?

 

Fred, AB1OC

[Harry Mueller]

Thanks Fred!

I don’t know why I never noticed the meters moving that much before. I only started noticing it after I changed my coax from a 165′ run of RG8X to a 111′ run of LMR400.

Unfortunately, I forgot to follow scientific method and changed too many variables. At the same time that I changed the coax I also changed from a 72′ end fed to a 124.5′ end fed and got the ends up another 15′ but with a 20-30 degree shift in the broadside face.

I hear other stations but they are very quiet and hard to see on the scope without turning the Ref up to +10db or higher. I feel like this is new but can’t say that as an ironclad fact.

I can’t say for sure there has been a change in my signal getting out. I’m still making contacts on phone but it seems harder. Of course I’ve been chasing POTA activations so the other stations are mostly QRP with portable antennas which doesn’t help.

–Harry

[Nashua Area Radio Society]

Your 72′ antenna was between a 1/2 wave and 5/8 wave on 40 meters, so primarily radiated in the broadside direction. 124′ is approximately a full-wave on 40 meters. It still presents a high impedance at the end, but now it will have a 4-lobed pattern, roughly 45 degrees away from broadside. (These patterns become closer to omnidirectional as the antenna is lowered below 1/2 wave above the ground, though.)

[Fred Kemmerer]

You might want to consider setting up WSJT-X and running FT8 with your current setup. If you do this, try calling CQ and then going to PSKReporter to see where you are being heard and at what S/M levels. This will give you an idea of how your station is actually doing. We have a Tech Night on setting up and using FT8/WSJT-X and PSKReporter if you’d like some help on getting started with these tools.

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