Icom 7300 ALC using FM query

[Dereka5]

I've only recently bought a 7300, & I'm curious as to whether or not the ALC (blue bar) should be lit up when transmitting in FM mode.

As far as I'm aware, ALC is only used in SSB mode - but on mine, the blue bar lights up when keying in FM mode.

Is this normal behaviour, please?

Also, when modulating on SSB - is the general consensus to totally avoid going into the red with the ALC, or will it be OK if the odd peak goes into it?

Many thanks.

 

[Dereka5]

Anyone, please?

 

[BJ radionut]

ALC: really has no purpose on FM...audio on FM is thru the "deviation" control circuit.
However depending on rig, your "mic gain" still has some control.
SSB: best to keep the level where it runs about 75% of scale. Tickling the "Red" ok in most cases, but should not be "habit" forming.
When using compressionprostrasher) keep about 50-60% ALC and run about 5 db compression...seems to work well for most...
Set ALC without compression...then add prostrasher do not change mic gain level.
My 2 cents worth
My audio settings for other bands total big difference than 6m...(10 meter setting very close)
I use narrow bandwidth (2.4kc) and very sharp high end audio on 6 meters...cut off low end audio at like 700 cycles ...increasing mid-range and high's
All the Best
Gary

 

[sp5it]

What 7300 manual says about that?

 

[Justme]

Driving the last watt out of the traansceiver won't be noticed on the other end, your Fets will have to work quite hard though, my 991 A has higher ower fets and can do 100 watt all day long.
Overcomprssed or heavy ALC limited audio doesn't sound that good as well.
I drive the FT991A with just a tad ALC, no compression from the 991A but use the limiter compressor of the EQplus sensibly.
If i need more power there is the Heathkit SB-1000.
I just want clean crisp audio without overdriving the chain.

 

[Moleculo]

The 7300 has a reputation for being overly aggressive with the ALC on SSB, limiting the overall average power as a result. Rumor is that Icom did this on purpose for "cleanliness". Follow the procedure that BJ outlined but try to keep the ALC meter reading around 50% scale. On FM, just ignore it.

 

[Dereka5]

Many thanks all for the good advice - I will take heed of it.

At present, I set the ALC on SSB to 25 > 50% with compression off, mic gain at 20%, then turned compression to 4, and this peaks at around 90% with the occasional tickle of the red with loud voice.

I'll turn compression down to around 3, leave mic' gain the same, and hopefully this should see around 75% on the ALC.

The Icom manual & some other places say to set compression to average 10 > 20dB, but I find this too much, so set my compression to peak at 10dB.

On another note; FIL1, FIL2, & FIL3 at the top - are these merely RX filters, or do they alter TX parameters, too?

 

[Moleculo]

On another note; FIL1, FIL2, & FIL3 at the top - are these merely RX filters, or do they alter TX parameters, too?

Double check the manual because on some of the Icom rigs, the filter also affects the transmit BW on certain bands/modes like 440 mhz. I know the 7100 does this; I don't recall if the 7300 does or not.

 

[Dereka5]

Double check the manual because on some of the Icom rigs, the filter also affects the transmit BW on certain bands/modes like 440 mhz. I know the 7100 does this; I don't recall if the 7300 does or not.

I later found out that these filters I thought were only for RX also apply to TX, too.