• You can now help support WorldwideDX when you shop on Amazon at no additional cost to you! Simply follow this Shop on Amazon link first and a portion of any purchase is sent to WorldwideDX to help with site costs.
  • Click here to find out how to win free radios from Retevis!

Ssb audio distorted when using amplifier

Damo666

Member
Jan 10, 2009
50
0
16
Hi guys. I am having some problems. When i use my radio with no amp in use on ssb my audio is a good q5 according to everyone i request reports from. However, when i attach my amplifier everybody says the audio is very scratchy and darlicky and generally crap. I've altered the gain on my mic and even lowered the drive power, but people say it sounds terrible. Can anybody assist please? I'd be very grateful for any feedback.
 

Hi guys. I am having some problems. When i use my radio with no amp in use on ssb my audio is a good q5 according to everyone i request reports from. However, when i attach my amplifier everybody says the audio is very scratchy and darlicky and generally crap. I've altered the gain on my mic and even lowered the drive power, but people say it sounds terrible. Can anybody assist please? I'd be very grateful for any feedback.


With the amp on or Off?

If on, is the amp biased for SSB (Class B or AB) or is it a Class C amp?
 
Hi guys. I am having some problems. When i use my radio with no amp in use on ssb my audio is a good q5 according to everyone i request reports from. However, when i attach my amplifier everybody says the audio is very scratchy and darlicky and generally crap. I've altered the gain on my mic and even lowered the drive power, but people say it sounds terrible. Can anybody assist please? I'd be very grateful for any feedback.

RF ??
 
Thanks for the numerous responses. The amp is a zetagi b47. I don't know what class it is, but there's a schematic on the cb tricks website. The audio is perfect when the amp is off, but awful when switched on. By the way, there's a ssb/am switch. I've tried it switched both ways. Cheers.
 
Could be RF feeding back into audio section dirty amplifer but more info would help class of amp A/B biased?

Ok. If the amp has a SSB switch it is probably biased for that mode. I'm kinda with Tony up to this point. Sounds like an RF feedback issue which could be remedied with some proper grounding and a check on how good a ground you have on the antenna install. I had the same issue once in a previous mobile install and the extra grounding took care of the issue.
 
Ok. If the amp has a SSB switch it is probably biased for that mode. I'm kinda with Tony up to this point. Sounds like an RF feedback issue which could be remedied with some proper grounding and a check on how good a ground you have on the antenna install. I had the same issue once in a previous mobile install and the extra grounding took care of the issue.

the audio is perfect on fm and am with the amp, and it's also good on ssb without the amp switched on. I use a 1/2 wave basic vertical. Suggestions as to grounding my system would be appreciated. Would joining a wire from the bracket of my antenna into the garden help do you think? I'm willing to give anything a try to eliminate this problem. Cheers again.
 
First, let me preface this by saying that I'm not that great at reading schematics...

...but I just looked at the schematic for that amp and it looks like a class C amp to me. It's using FETs and I'm not very familiar with amplifier design with them. Perhaps someone else can look at the schematic who is better than me. The SSB switch on the schematic is clearly just switching a capacitor inline with the relay to keep the relay from chattering in SSB mode.

If it's a class C amp, you're going to have this problem on ssb. You still didn't say what radio you're using.
 
First, let me preface this by saying that I'm not that great at reading schematics...

...but I just looked at the schematic for that amp and it looks like a class C amp to me. It's using FETs and I'm not very familiar with amplifier design with them. Perhaps someone else can look at the schematic who is better than me. The SSB switch on the schematic is clearly just switching a capacitor inline with the relay to keep the relay from chattering in SSB mode.

If it's a class C amp, you're going to have this problem on ssb. You still didn't say what radio you're using.

cheers for the reply. I also noticed that all the ssb switch does is switch in a cap. I'm using a Superstar 3900 turned down to 4 watts on fm/4 watts pep on ssb. Can anybody else confirm that this amp is unsuitable by viewing the schematic please? Cheers.
 
Is this a base or mobile? How are both units being powered? Running both on too small a power supply or the amp on small feed wire and a week battery can cause what you are seeing.
 
Is this a base or mobile? How are both units being powered? Running both on too small a power supply or the amp on small feed wire and a week battery can cause what you are seeing.

I'm base. I'm running the radio and burner from the same battery. And the power cable is rated at 10 amps. I'm beginning to think that the amp circuitry isn't designed for ssb, even though a ssb switch is on the unit. Have you had a look at the schematic?
 
I think you are drawing too much from the battery when the amp is in-line and turned on. If you starve an amplifier it will sound like crap. Buy a decent power supply and go that route. My money says thats your problem. I did a google search on your zetig amplifier, it has a SSB delay so it will work on SSB.
 

dxChat
Help Users
  • No one is chatting at the moment.
  • @ Crawdad:
    One of the few times my tiny station gets heard on 6m!:D
  • @ Galanary:
    anyone out here familiar with the Icom IC-7300 mods
  • @ Crawdad:
    7300 very nice radio, what's to hack?
  • @ kopcicle:
    The mobile version of this site just pisses me off
  • @ unit_399:
    better to be pissed off than pissed on.