ALC settings - doh!

[SR385]

O.k. I'm not above admitting mistakes, but this one really made me laugh. Thanks to QRN for rattling my cage a bit and making me think this over.

I know what ALC does, but for some stupid reason, and for years, I've misunderstood what 'meter deflection' meant. I was thinking that deflection meant it should bounce back from the end of the right side of the meter...

Meter deflection, means any level indicated when the meter is in ALC mode. My Kenwood has a range for ALC and it should be right at the end of the fat ALC bar on the meter on voice peaks. My 857 just has a plain indicator and a few bars on the avg peaks is where that should wind up.

ALC can be looked at as a compressor limiter and having worked for years as a sound engineer, I'm not sure why this confusion even happened with me. Basically it will clip off the peak levels and bring the top end of the dynamic range down to meet the middle as you drive into the ALC circuit.

To get the best talk power/efficiency you want your peaks 'grabbed' by the limiter but you don't want it engaging on your mid level speech or it will make you sound all boxy.

Needless to say I haven't had the ALC set properly on a rig until now... and I've used HF rigs for a long while so this is particularly embarrassing.

So now my Kenwood 680 and the 857 Yaesu are all buttoned up the way they should be and wouldn't ya know it... the Yaesu mic gain settings are much much more even between the modes LOL.

Cracked me up to figure this out.

From what people told me giving audio reports, they couldn't hear much of a difference oddly enough. It may be the nature of my voice or something, but I would have sworn that someone would have complained about overdriven audio before this point. I was basically pounding all my rigs right into the limiting and didn't even know it. Generally you can clearly hear when someone is burying the ALC. Go figure.

Thanks to QRN for making me go back and think my setup over and hopefully this helps someone else.

 

[Master Chief]

What 385 DIDN'T say is what the correct meter deflection SHOULD be.

Its simple really, the more bars or meter deflection, the more the ALC circuit is trying to clamp down, which means your audio is too hot.

You want only a few bars or slight meter deflection!

If your ALC is bouncing off the right side, its WAY TOO HOT! Turn your mic/drive down until you only see a slight deflection. This is NOT a modulation meter or a "swing" meter! (Dude, check it out, I got my ICOM SWINGING, 4-10!)

 

[bob85]

most people dont seem to hear the loss in dynamic range when you drive the transmitter hard into the alc region, some even seem to like it, their receiver agc also helps mask the effect,
people that listen with agc disabled and rf gain set just right are more likely to notice whats going on

 

[SR385]

As a sound engineer I was pretty embarrassed that I had this backwards.

It's interesting what people think is solid audio.

I just spent some time on 80m and fixed up about four guys over the last few days running the W2IHY 8band EQ/gate mic preamps with various mics and rigs.

The other rig I worked on with a few is the FT-2000 Yaesu that has a parametric EQ inline with the TX audio.

Only takes me a few minutes to get them cleaned up as I can pretty much call frequencies out by ear from working with EQs so long. With a bit of patience and cooperation I can get a guy on a $49 dynamic mic to sound like he's a broadcast station. Really no need for the $600 Neumann mics for this.

The primary violator in muddy audio with these guys starts with overdriving ALC and here I knew that was the trouble but didn't even know my OWN was fouled up.

Next is how they are talking into the mic...too close, too far, off axis etc.

Next up is the damned pop filter foam screens people put on their mics...darkens all the definition right out of the mic.

Next would be setting a noise gate improperly so the threshold is too loose and it isn't downward expanding the background enough.

Next is overdriving their amp or not having it tuned up properly.

It isn't hard to tweak all of these, but it's hard to find someone who can give you good advice vs what your own transmit audio sounds like.

I think I'm going to get myself one of those RF taps so I can have a proper monitor.

 

[Captain Kilowatt]

I think I'm going to get myself one of those RF taps so I can have a proper monitor.

I like the one already built in to my TS-820S. It makes taking a 'scope reading extra easy. It also has an IF out jack for looking at others peoples signals.Sometimes I use both at the same time on my dual trace scope and look at my signal as well as the guy I am talking too.

One thing I did was wind a small torroid and slip it over the wire going to the input jack of my dummy load.I wired a separate BNC jack to the windings to give me a good isolated RF pickup point.

Glad you got things worked out BTW. I just knew something was not quite right with your settings.As for people giving you on-air reports, well I have learned that it only works when the person knows how you sound in person and if they actually know what good audio is supposed to sound like.I have listened to many conversations where a guy was told he had great audio and I was gagging.Mostly because of the loud fan on the amplifier he was running that could be heard almost as loud as he was. :roll:

 

[bob85]

"I have listened to many conversations where a guy was told he had great audio and I was gagging.Mostly because of the loud fan on the amplifier he was running that could be heard almost as loud as he was"

amen on that and it aint just fans,

i found an old set of instructions for a very popular base microphone a few years back ( now out of production )






"we are are proud to inform you that you have just purchased the very best high gain dual stage amplified cb/ham microphone available"

your new microphone has several usefull features that ensure ease of use and many years of trouble free operation

durable chrome plated brass construction
dual ptt mechanism
user serviceable leaf type contacts
large omnidirectional aluminum diaphragm piezo ceramic cartridge
super high gain dual stage fet amplifier
matches most radios with input impedance 200ohms-5kohms
variable output level 1mv-1500mv @1khz

to help you get the most out of your new microphone we have included some guidelines for your convenience




install your tranceiver in a room with hard plain painted walls and remove all soft furnishings,
for optimum results remove the carpet and tile the floor, if you dont have a spare room the bathroom will be the next best option especially for contesting where time away from the radio = missing that rare dxcc and gives the other guy a chance to get on the watergate,

remove the battery cover found under the base of the microphone and install the suplied 9v battery ensure correct polarity as indicated on the battery cover

turn the microphone gain controll fully clockwise then place it 6" from your linear

sit 3 feet or so from the mic arm outstretched at any old angle and keep moving

ensure the wife has the volume on the tv in the next room adjusted correctly so your buddy dont miss whats going on in the soprano's while his wife is watching the home selling channel
if hes struggling leave the door ajar or have your wife turn it up a little,

to be sure your perfect open the window and have the kids torment the dog in the yard with a whistle,
if you dont have a dog buy one,
a timberwolf alsation cross is highly recommended, avoid basenji's at all times,

make some contacts and start reducing the microphone gain controll by turning it counterclockwise in small increments untill you find a station that does not complain

your microphine is now setup correctly.




for parts and servicing contact

arsetatic corp connaut ohio

 

[Captain Kilowatt]

Good one Bob. IT sure seems that a lot of folks set up their D104 exactly that way but forgot to read the last line of the instructions.

 

[74IN]

I just saw this, that's funny. I think lots use the radio as per the mic instructions.