RM KL 203 arrived....

[144inBama]

So, Mother Russia finally delivered the amp today. Hooked it up and fired her off....90 watts PEP (45 AVG) on the Daiwa. So I'm thinking...why not drive the DX500 with it? Hooked the jumper between the two, turned the variable on the radio all the way down, powered them both on and slowly raised the dead key until the 500 keyed @ 100 watts. Gave her the all popular and annoying aauuuuudiiiiooooo and she went to around 375 watts AVG. and around 650ish PEP. So I'm thinking, again, lets see if I can kill the 500 (we have a history for those who don't know) so I ran it wide open for about 20 minutes with the cooling fans off....She survived...too hot to touch the heatsink so I turned the fans on and let it cool off. So, much to my surprize, the 500 seems to be more robust than my 1st impression ...a LOT more robust.
Now there is one question I have for the gurus here.... On AVG, if I have my mic gain wide open, when I finish the "audio" the needle will ever so slightly jump up, if I cut the mic gain back to 1/4ish, it swings to the same point as the "jump", on PEP it doesn't do the jump but I don't get full swing on the power meter unless the gain is at least 3/4. What causes this? Radio checks tell me they can't tell any difference on the S meter between the 1/4 gain and the 3/4, but the audio is very different (obviously)....is this just one of those things?

 

[ForestRunner98]

That’s so cool running the KL203 to run the 500 amp!! I can’t help you with the questions but I wanted to comment. Your 203 came from Russia??

 

[w9cll]

So you're using a dirty amp to feed a dirty amp ?

 

[144inBama]

That’s so cool running the KL203 to run the 500 amp!! I can’t help you with the questions but I wanted to comment. Your 203 came from Russia??

Yes sir, for the wonderful price of 38 bucks, LOL.

So you're using a dirty amp to feed a dirty amp ?

As long as it sounds good to the people I'm talking to...and it doesn't bleed 5 channels, call it what you like.

 

[buickid]

Adjacent channels are one thing, harmonics are another thing...

 

[w9cll]

As long as it sounds good to the people I'm talking to

okay if you say so

 

[144inBama]

Adjacent channels are one thing, harmonics are another thing...

Nothing a couple of low pass filters won't tame. one after the radio, one after the amp....providing I even continue to run that setup, which I doubt I will. I only ran it to see if the 500 would die or not. I bought the 203 for a little project outside of the CB hobby.

 

[ForestRunner98]

Adjacent channels are one thing, harmonics are another thing...

I am using the RM low pass filter...cut those harmonics right out.

 

[Captain Kilowatt]

Nothing a couple of low pass filters won't tame. one after the radio, one after the amp.....

Ummmmm.....no not really. Once distortion is created by over driving no low pass filter or any other filter in the world will cure it. Same as for any IMD or in-band crap that may be generated by running such a set-up. Once an amp is driven into compression the output purity starts to go downhill fast.

 

[144inBama]

Ummmmm.....no not really. Once distortion is created by over driving no low pass filter or any other filter in the world will cure it. Same as for any IMD or in-band crap that may be generated by running such a set-up. Once an amp is driven into compression the output purity starts to go downhill fast.

So the answer to my question is "it's being over driven"?

 

[357magnum]

Hmmm ? I " Try " to keep it clean on 11m . Wiping out 5 channels .... maybe not but 3 each side for sure . ( Imo ) Good Luck ! Looking for a New Bigger Amp now , But RM is not on the list . Stay Healthy & Safe ! 73 & God Bless ! Leo . Ps , I mean NO Disrespect . But been doing this 50 years & I know what I hear . Also I am Not a Ham Op .

 

[Shadetree Mechanic]

The rm would be better on an 8 pill amp.

 

[9C1Driver]

A Texas Star 500 only needs a radio as a driver. On SSB you can get full output with as little as 12-16 watts PEP in. It's his amp and his money I guess.

 

[M0GVZ]

Now there is one question I have for the gurus here.... On AVG, if I have my mic gain wide open, when I finish the "audio" the needle will ever so slightly jump up, if I cut the mic gain back to 1/4ish, it swings to the same point as the "jump", on PEP it doesn't do the jump but I don't get full swing on the power meter unless the gain is at least 3/4. What causes this? Radio checks tell me they can't tell any difference on the S meter between the 1/4 gain and the 3/4, but the audio is very different (obviously)....is this just one of those things?

The ALC. You're overdriving the audio input so the ALC is limiting it to try to do something to preserve a half clean signal that's mostly transmitting on the frequency you're tuned to. They won't notice any difference on the S meter at the other end because to gain a single S point requires a doubling of power and to lose an S point requires a halving of power output and you're not losing that much.

The only correct mic gain is the one that gives you the maximum power output on voice peaks with the lowest setting. And yeah if you crank the mic gain right up the audio will be very different, it'll sound like an overdriven distorted pile of unintelligible shit. Italy is close to me and it's a country with lots of hams who drive everything at 11. It's as funny as hell listening to them screaming their callsign into their mikes and the DX station giving up because even I can't understand what they're saying despite them being 40 over 9 to me so the DX station has no chance then I pop in with my weedy 100W and decent set up audio and make it first call.

First day I gave my President McKinley a try someone commented on my audio and asked what mic I was using. I was using the stock mike. They wouldn't believe it and asked what I did. The answer was simple, I backed off the mic gain and set it up the same as I do my ham gear.

 

[w9cll]

The ALC. You're overdriving the audio input so the ALC

You are so right