MADISON AUDIO GREAT ON AM WITH AMP BUT SSB AUDIO NO GOOD

[Stellasstillarat]

Lowered the am dead key to 21/2 on am amp works fine. Great audio reports but people on ssb say audio is horrible. Problem is I dropped ssb pep to 6 watts. If I dont turn the mic gain and d104 almost all the way up or the ssb won't engage. The amp doesn't have a ssb switch. It dose have ssb recognition but if the I turn the audio down the amp keys intermittently. Tryed so many different combinations of mic gain up d104 down and visa versa. Should I raised the pep back to 12 and just keep the the mic and d104's gain down. Strange thing is a few days ago all skip contacts gave great reports until the 25amp fuse blew out in the amp and after I replaced it ssb audio reports are horrible. I did use deoxit on the amps switchs while changingt the fuse. I don't know anymore. I do have a few small issues with the radio and I am willing to send it out but can't finf a real tec. Im really enjoying ssb but it's the current problems giving me a headache. I may just hang on am and hook my ffs2340 back up and put the Madison back in the closet. It's frustrating when you have no knowledge or ability to work on cb's.

 

[AudioShockwav]

You can raise the SSB pep back up to 10/12 watts.
If you are worried about overdriving your amp it will not be a problem.
SSB is not as hard on amps because the amount of time that the radio is at peak output is considerably reduced on SSB mode.
An example ....take the Ameritron 811 amp.
This amp is capable of 600 or so watts on SSB, but should be limited to about 100 watts carrier when using AM mode.
Or a Radio example is the Yaesu FT-101 series of radios, most will easily do 100 watts on SSB, but on AM mode the carrier should be limited to 25 watts.
You should be fine.
You may need someone to increase the size of the cap used in the Amp to hold the SSB delay a bit longer.

73
Jeff

 

[hotrod]

sounds like your amp prefers the normal 10-12 watt pep on ssb. as you stated
when ya fuse blew did you replace with the exact same one ? if so then shouldnt
be any issues. play around again with mic gain/d104 gain but with radio doing
at least 10-12 watt pep. in my finds with d104s i turn them all way up then
use mic gain on radio to adjust audio. as backards as this is ive seen better number
on my watt meter and amp meter by doing this. also wont need a screwdriver
all the time ..lol

 

[9C1Driver]

Turn the SSB power back where it belongs and get rid of the D104, it's a poor mic choice for SSB talking. If the amp is the 4 pill amp you have been asking questions about I don't think a 25 amp fuse is correct. It should be at least a 30 and possibly a 40.

I have a Madison that has nothing done but a factory tune and alignment. The dead key is set at 2.5 watts and swings 14-15 on AM, the SSB peak is 15-17 watts. This radio has working fine with numerous amplifiers over the years.

 

[ExitThirteen]

Problem is that the amp is class C. But the higher output from the radio and the high mic gain allowed the amp to stay "keyed" or "turned on" in between words, so it takes away (most of) the "choppy/crunchy" audio. Reducing mic gain and/or SSB output from the radio will make the amplified output sound bad. The best way to fix this is to get the amp re-biased in class AB, then mic gain and power input into the amp will not make any difference, it'll sound good. But for now, best way to fix the bad SSB audio is to turn the SSB power back up in the Madison, and turn up the mic gain again. Good luck.


~Cheers~

 

[Tallman]

What brand is the amplifier? If it is RMItaly they don't like high in put drive. The kl-400 and kl-500 will smoke transistors in a heart beat. The MS-1051 transistor is not very robust and over heat and blow real quick.
The suggestion by Exithirteen is right on about the AB biasing. If it sounded good before the fuse popped, you might have blown a transistor or two.

 

[9C1Driver]

What brand is the amplifier? If it is RMItaly they don't like high in put drive. The kl-400 and kl-500 will smoke transistors in a heart beat. The MS-1051 transistor is not very robust and over heat and blow real quick.
The suggestion by Exithirteen is right on about the AB biasing. If it sounded good before the fuse popped, you might have blown a transistor or two.

The amp is a Palomar/Boomer base style 4 pill amp that has a built in power supply. There is no way a Uniden Madison run on SSB at 12-16 watts will overdrive that amp. Also, I ran my Madison into a KL203 at 15-17 watts PEP on SSB and it worked great. A KL 400 or 500 should be fine at that drive as well on SSB.

 

[Tallman]

I ran my Madison into a KL203 at 15-17 watts PEP on SSB and it worked great. A KL 400 or 500 should be fine at that drive as well on SSB.

You were lucky. A company that I associate with deals directly with RM Italy. They were having a lot of amps dying right out of the box. We sent them back to Italy for failure analysis and the cause they quoted in 99% of the failures was "Unit Overdriven, Excessive Input Amplitude." They are the ones that reccommend the 2.5 to 3 watt drive.

Also he got good reports on the amp and audio until he popped a fuse. Afterwards the reports were negative.

 

[9C1Driver]

The 2.5 - 3 watts drive is carrier or dead key input, a KL203 will run for years at 10-12 watts PEP in SSB mode.


Here is a copy and paste for the KL203.
" Specifications: 3-RM-3 Transistors, *Freq Range: HF, Mode: AM/FM/SSB/CW, *Input power: 0.5-10W AM/FM, 2-20W SSB/CW, *Output power: 100W Max. AM/FM, 200W Max. SSB/CW, *12A Fuse, Electronic Switch, *Inversion Polarity Protection, Comes with Schematics. "

 

[Tallman]

As I stated the report was from RM Italy. They need to redo those in box manuals. The KL-203 runs with FOUR RM3 transistors.

 

[9C1Driver]

As I stated the report was from RM Italy. They need to redo those in box manuals. The KL-203 runs with FOUR RM3 transistors.

If they are trying to market amplifiers that can ONLY run with a peak wattage input of 2.5-3 watts then they might as well give it up. Show me a cb radio that can dead key 2.5-3 watts with no swing, that ridiculous.

The reason people burn them up is they try to run 20-40 peak wattage into them. I see cbradiomagazine has the same input numbers. You are mis-understanding this "report" from RM Italy or they are nuts. Anyway nuff said.

http://cbradiomagazine.com/KL203.html

 

[bob85]

palomar boomers are well known for sounding poor on ssb,
every one i have seen has been class C ,
they are unstable/ prone to self oscillation, especially if you enable the bias circuit.

rmitaly tell lies about input and output ratings,
you will be lucky to see half what they claim on a good peak reading meter, they double the ssb ratings and call it pep to impress the gullible,

10w am/fm input will burn power sellector resistors and have feedback resistors falling out of the board, they also sell class C amplifiers with ssb delay switch,

kl203's go into gain compression at 4-5w drive,

w8ji tested the hla150 and tells the truth about rmitaly amplifiers.

 

[Tallman]

9c1driver said, "The reason people burn them up is they try to run 20-40 peak wattage into them. I see cbradiomagazine has the same input numbers. You are mis-understanding this "report" from RM Italy or they are nuts. Anyway nuff said."

The information came straight from the engineer that designed it. If you are misunderstanding the report go talk to him. He speaks English quite well.

 

[Tallman]

That's right about the gain compression on the KL-203's. Actually a pretty good little amplifier for the money.

 

[9C1Driver]

9c1driver said, "The reason people burn them up is they try to run 20-40 peak wattage into them. I see cbradiomagazine has the same input numbers. You are mis-understanding this "report" from RM Italy or they are nuts. Anyway nuff said."

The information came straight from the engineer that designed it. If you are misunderstanding the report go talk to him. He speaks English quite well.

Can you make a radio suggestion then to run with a KL-203? And please list what wattage numbers the radio should be set at as far as AM dead key and peak input. SSB power setting as well. I would love to hear this.