SSB Carrier Supression

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Hey flat5, check this out. When I added that crystal I think my signal was too narrow. That's why it would pick up my frequency on the freq. counter through the air at only 8 watts. So I guess by being so narrow it caused the feedback, because I noticed my signal being tinny, so I jumpered over the last crystal with a capacitor until it was wide enough for voice fidelity but still good image rejection. Then I re-hooked the amp back up & it was fine....lol.

So I guess it was too focused at one frequency where the rf fedback. It does show I've got some leakage somewhere.
 
I have changed my Hartley VXO. It is so tight I can lay my hand on the coil and the frequency will not move!

It is variable to 5KHz with solid lock. The only draw back is in order for it to start up on the crystal as main tuning source or in other words, at or near the crystal frequency, it must be set about 5 KHz above. Another way to explain it, is if I set the VXO to the crystal's frequency it will have a very hard lock. But, when I turn it off and then back on again it will come up out of lock usually far below frequency. If I tune it back into lock, it will end up at 5KHz above frequency with hard lock again. I can turn it off and back on and be at same frequency. If I tune down to even 2KHz above crystal freq. and turn off then on, it will be way out again.

Also, the PLL is more solid. Before I could hear it rail jumping. I believe it is because of the higher Q

I will post when I figure it out...lol
 
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Here ya go.

Merry Belated Christmas

Got some old notes about a coil that was removed....just disregard.
 

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Hey flat5, if you around later. Listen, I got no problem running at 8 watts. Nobody even knows I'm home brew. But when I hook up the 80 watt amp I get reports of distortion. Now I got stupid and wanted to proceed with the transmitter design and grabed the only connectors I could find and have two power wire & a signal wire from modulator to 8 watt amp and they are just open audio connectors and the males are plastic enclosure. That's probably what's wrong huh? RF getting into those connectors. I'm gonna have to break down and get some BNCs or something.
 
I'm just staring at a screen. I don't know what's happening.
You're in charge. Attack from all angles. Ground, beads, shielding.
 
flat5 said:
I'm just staring at a screen. I don't know what's happening.
You're in charge. Attack from all angles. Ground, beads, shielding.
Click to expand...

You know what? Your right. That's the smartest statement I've seen said on here.....really

Yeah, I'm gonna try the signal wire first. I'll let you know how it works out. At least I know my frequency is locked tight. I blew those guys minds this morning. I told them I was in Atlanta using 8 watts and they were in St Louis. They couldn't believe I was using 8 watts.
 
Lets see...

25w on 3.6Mhz
12.5w on 7.2Mhz
6.25w on 10.8Mhz
3.125w on 14.4Mhz
.
.
.
If we sum all the harmonics up to infinity, I guess I could just about make it 50w.

JimB
 
JimB said:
Lets see...

25w on 3.6Mhz
12.5w on 7.2Mhz
6.25w on 10.8Mhz
3.125w on 14.4Mhz
.
.
.
If we sum all the harmonics up to infinity, I guess I could just about make it 50w.

JimB
Click to expand...

How about 80 watts on just one of those freqs.? We are talking MRF454 ?
 
I know what I'm gonna do. I'm gonna take all this crap and put it in a metal cabinet and ground it. That way I don't have to guess where the rf is coming in at. It will be shielded.
 
bryan1 said:
That has to be the worlds worst peice of a crap circuit I've ever seen.....
Click to expand...
There is a reason for all the extra solder and flux in the circuit:
When it overheats and the components desolder themselves, the extra flux helps the solder reflow nicely, making a better solder joint than was there before.
 
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You have a good >80 watt dummy load?
Pump the 80 watts into that and see if the "feedback" is gone or if you can sniff where it's coming from. I'm thinking a good ground or shielding won't matter so much in this scenario (or Sinatra, as my spell checker thinks). The power amp should be shielded in any (metal) case.

wha-da-ya thinks?
 

In a pinch, a 100W light bulb will work as a dummy load.
 
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