President McKinley EU "talking up" problem on SSB.

[Dereka5]

With the stock Electret Mic', I'm lucky to get around 1.5W average power on SSB. With a decent amplified Mic' set at full, I'm still only seeing around 2W, maybe less.

Only a whistle next to the mic' can see this rig do 12W peak, and it's nowhere near attainable with speech, even loud speech or a raised loud voice.

The output power of this as it stands is nowhere near good enough to drive a KL203 to it's full potential, so it definitely won't be any good for my bigger amp.

The rig mic' gain is set to maximum, the power amplified mic' is set to maximum, so I'm now stumped.

Can anyone please help?

 

[ForestRunner98]

You might need to adjust your ALC and power pots to factory specs. Those are inside the radio.

 

[nomadradio]

I don't think the problem is the radio. Sounds more like an average-reading wattmeter.

I suspect a true (not passive, but true) peak-reading meter would show voice peaks roughly equal to the 12 Watts shown with a whistle on this meter.

73

 

[freecell]

maybe this will help.

 

[Dereka5]

Thanks for the replies, guys.

When I bought it, the ALC (RT103/SSB Hi) was set to 20W and I was only averaging around 3 > 4W on that setting shouting into the mic'.

I only recently reduced the ALC (RT103/SSB Hi) to 12W PEP.

I have a fair few other SSB rigs, and these are all easy to "talk up" but this McKinley is dismal for this.

Apart from the ALC, would any other preset help me to average a bit more power?

As said, a power amplified mic' improves things slightly, but it's as if something is restricting the audio in the rig.

 

[nomadradio]

This is tricky business without an oscilloscope. The correct adjustment is to set it where the pointy voice peaks stop being "flattened" on top.

Not so easy to do with a wattmeter. 40 years ago, when average-reading meters were mostly the rule, I would tell a tech to start with the ALC at max power. Modulate the radio with your voice, slowly turning the ALC trimmer until it "kicks in" and the wattmeter takes a sudden downward jump. Odds are the reading will be one-third to one-half what the "wide open" reading had been.

That abrupt downward-shift point while turning the ALC is where you want it.

Setting it for some arbitrary desired wattage number runs the risk of cooking the final transistors.

73

 

[Dereka5]

Hi Nomad,

When I was setting the ALC level, I merely played a 1Khz sinewave tone into the microphone & turned the ALC (SSB power) down to 12W.

I thought an Oscilloscope was only needed for setting modulation & some other parameters to avoid flat-topping.

In the McKinley service manual, it just tells you to adjust the ALC with two tones & an RF wattmeter to 24W. No mention is made of a scope.

I literally thought ALC was automatic level control - IE SSB power limiter.

 

[Handy Andy]

What you might want to do, is compare that Mckinley to the others - listening on one while you key up the 'kinley to test the settings for ALC and AMC.

Usually I see what when ALC and AMC are set too wide (wide open throttle no limit) the radio seems to sound weak because it's not in any sort of compression - so the mic even though you're bullhorning it - seems like you might be talking thru a Dixie Cup...

No! Not those...

I said Dixie CUP - not Dixies' Cup sizes!

Google is so helpful these days...

​

What I'm referring to is a type of audio compression that is derived from the distortion-effects caused by the clipping that increases the audio presence by INDUCING a clipping-type of distortion that actually help to improve the drive the system can produce.

Intelligibility is improved and you hear your audio mixing with the drive better because of the ability to compress more signal into the RF wave thru that process. You will see higher RMS - AVG wattage results because of this.

How to prove that requires you to listen to your McKinley on another radio while you adjust the ALC and AMC and Mic gain controls all together on the 'kinley to form the clipping level and drive compression that begins to form; you'll begin to hear yourself as a LOUDER audio on the monitor radio - you just have to tweak that setting.

Even a simple MOD meter can show this too - that's the clipping help to drive that RF signal - it's compressing it.

 

[Dereka5]

What you might want to do, is compare that Mckinley to the others - listening on one while you key up the 'kinley to test the settings for ALC and AMC.

Usually I see what when ALC and AMC are set too wide (wide open throttle no limit) the radio seems to sound weak because it's not in any sort of compression - so the mic even though you're bullhorning it - seems like you might be talking thru a Dixie Cup...

View attachment 46632
No! Not those...
View attachment 46633
I said Dixie CUP - not Dixies' Cup sizes!
View attachment 46634
Google is so helpful these days...

​

What I'm referring to is a type of audio compression that is derived from the distortion-effects caused by the clipping that increases the audio presence by INDUCING a clipping-type of distortion that actually help to improve the drive the system can produce.

Intelligibility is improved and you hear your audio mixing with the drive better because of the ability to compress more signal into the RF wave thru that process. You will see higher RMS - AVG wattage results because of this.

How to prove that requires you to listen to your McKinley on another radio while you adjust the ALC and AMC and Mic gain controls all together on the 'kinley to form the clipping level and drive compression that begins to form; you'll begin to hear yourself as a LOUDER audio on the monitor radio - you just have to tweak that setting.

Even a simple MOD meter can show this too - that's the clipping help to drive that RF signal - it's compressing it.

Cheers for the good input, Andy.

I always thought the AMC preset was for AM modulation & not SSB.

I can definitely do what you're asking & will get onto it later today, time permitting.

So, in a nutshell, there's a good chance the AMC preset hasn't been set correctly at the factory, and this is resulting in the restricted SSB AVG power I'm seeing, yes?

 

[Handy Andy]

Yes, in a way it still can.

In a nutshell, the McKinley uses ALC to limit RF peaks, but AMC and ALC use the SAME amplifier section to attain the limiting action.

IF the AMC is wide open, we still don't know if the ALC can be as effective as if AMC was working in UNISON with it.

They are different modes, but as far as I can tell McKinley is similar to the 980 - which is based upon a derivative of the Jackson, and the PC-122/Pro-810e line - a hybrid merged.

So the AMC if it's defeated, wont help with Audio Compression used on AM of FM modes - ALC can be the same way - they share a lot of the same support lines so if you take away one or just trimmer it off, the ALC is left to do most of the tasking it doesn't want to do - that also being RF limiting in other modes using envelope for peak - yes, that means AM too..

Since I was a bit pressed for time to post the above message, I also just wanted to touch on another aspect of this very issue of vocal sounds that the radio seems to be "flat" on. Much of that deals with "body" or fullness of sound.

The Mckinley does a great job of talking - weakly, but talking - why - well go to this thread...
https://www.worldwidedx.com/threads/president-mckinley-personal-review.246500/page-4#post-705283

That mic element may just need to be "opened up"

There are also 2 ALC adjustments...

If your version looks like this...
Locate SSB power (twin trimmers near centerline just above the output filter network).
​

To keep linearity - you have to adjust both.

When one on high power is set - you need to tweak low power too - one "pads" the other to attenuate the signal from the tap that is just past the final. There's a lot of power in it so these two are adjusted to give you the best overall fit.

 

[Dereka5]

OK - I eventually got around to opening the McKinley up today, & have finally accomplished my mission of talking up "good movement" in average power without having to shout & scream down the mic'.

I merely nudged very slightly RT207, AMC, and the rig is now working a treat with excellent audio reports actually capable of driving my amplifier.

I only moved RT207 enough to actually see a difference, and didn't go mad cranking it all the way over. I barely moved it, but the difference is now significant.

Some of the preset pot's don't function at all in "export" mode (widebanded) as my rig is, and these are; RT208 AM/FM low power, and RT210 ALC low.

I set RT208 & RT210 in unmodified mode as per the service manual, and set the remainder in expanded mode as mine is. I left FM deviation, bias, AM mod', and squelch settings alone as these are fine.

The low power setting on mine in expanded mode can't be altered, and is 6W FM and 2W SSB. It would appear the low power can only be set when the radio is stock & not expanded.

Anyway, it's now getting good reports & able to actually drive an amplifier without ranting & raving down the microphone.

As per the service manual, I've set AM to 10W and there's positive swing & good reports. FM is set to 20W, and SSB 24W PEP but mainly averaging around 3 to 5W during speech if that makes sense on AVG setting.

I could've really done with a scope & other bits of test equipment, but in all honesty, I've literally just tweaked ever so slightly the AMC & this has remedied the issue. I didn't go mad with it, and also took images of the position of the preset prior to doing it & it's barely moved.

@Handy Andy - you were absolutely on point saying the AMC was part of the audio chain on SSB here, so I take my hat off to you for your help & good knowledge.

For anyone else with the McKinley EU, here's the service manual - https://simonthewizard.com/2019/12/15/kinley-eu-service-manual-story/

 

[Handy Andy]

You are awesome!

Glad it worked out for you!

 

[Dereka5]

You are awesome!

Glad it worked out for you!

Nice one, Andy.