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Hello there

Is it correct that if im listening AM station on Fm Mod signal meter is bounching
like 3 or 5 then i turn to AM mod it`s shows only s 0.5 or 1 ?

Not sure if it's normal for the 440 but my 430 does the same thing and I would imagine that there is a logical reason but I cannot answer that.

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I U 212

I'm not sure if I'm understanding the question correctly but, this is one explanation for what you're seeing.
An AM signal's power changes almost constantly to some extent. That's why you see the 'S' meter wiggle. Am FM signal has a constant power level, what changes with modulation is the frequency, which stays centered on one particular frequency. That FM signal on an 'S' meter will show a constant power level.
Make sense?
- 'Doc

What mode is the transmitting station using?

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XDX74

I'd guess our 430's are very similar to a 440.

Just more memory channels and a different face.

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XDX74

it`s using AM modulation....im just wonder why so big difference...

W5LZ answered that question.

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If you're like everybody else,
you're about average.
73 de K7KBN

And just for grins...
You can 'make out' FM when in the AM receive mode. Have to do the tuning just right, and it'll never be very clear/plain, but it can be done. Doesn't work the other way around though. At least I couldn't make it work. Too easy to just punch a button to FM. Oh well.
- 'Doc

Another just for grins.

The '430 and '440 were similar, but not just a 'new box'. Big differences in how things were accomplished. Some aspects were better with the '440, some weren't. So what else is new?

Your rig is probably working normally.

Hammy rig's S meters are non-linear on FM due to the limiter stage in the I.F. amp. That stage is there to remove the AM response in an FM system. There is a lot more gain because of this. The S meter responds to AGC voltage. That voltage will be non-linear on FM due to the limiter.

If you wish to have relatively more accurate S meter readings for experiments use the rig on AM receive to take the reading even if it is an FM signal.

All this stuff is well covered in older ARRL handbooks. FM techniques are a lot different than other phone modes.

The 440 and 430 don't share much in terms of layout. The 440 has an additional 455 khz I.F. stage.