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Variable power 2510 Attn: Rogerbird

KD0FBK

Member
Aug 18, 2005
47
0
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Paola, KS
Hey you did a variable power mod to my radio, and I am not sure if this is right (it may be my junk meter), but the variable only seems to effect the am dk, it will swing the same not matter where you set it and it doesn't seem to change the SSB output at all. Is this right?

Oh by the way thanks for a great talking radio I get nothing but comments on the great sound.
 

The variable power will only effect the AM mode dead-key and the radio will always swing to whatever the radio was tuned for no matter where the variable control is set. SSB power will not be affected by the variable power control due to sideband having a modulated carrier. What you are experiencing is completely normal. Enjoy your radio! :D
 
There is one error on that mod page. The hookup shown will NOT affect SSB power output. At all.

And, getting the full swing out of the radio is the tricky part. Turning down the AM carrier tends to reduce peak power, too.

That's what's missing from that page, the procedure to set the TWO trimpots that affect the AM carrier so the swing won't turn down with the carrier.

73
 
Nomad, I assume that Rogerbird must know that becuse turning the DK all the way down (.6 watt) with the variable that has been installed, does not effect that swing at all.

Now with that being said on AM and SSB will swinging 15-20 into a TS DX350HD be a problem for the amp?
 
If I understand the thread correctly, your 2510 now can vary its deadkey down to any level you need, but the radio will still "swing" to whatever its max is (30-40 watts I'm guessing). If that's the case, then something is not right. I didn't thoroughly look over the mod specifics, but what I did see didn't show anything taht would cause that kind of effect. Having a radio keyed at 2 watts and peaking to 20 is not a good thing. If you've browsed this board for any decent length of time, I'm sure you've seen discussions of the 4:1 or 5:1 ratio that should be seen. It sounds to me as though your AMC circuit is not doing its job due to either being disabled, or due to the variable power mod somehow keeping the AMC from working.
 
Yep I know that, I don't need the radio to DK that low anyways it just does with the variable all the way down. As you said 4:1 should be good I think. I just didn't understand why it is still swinging that high.
 
Um, okay. There's more to retaining full swing on a 2510 than what the web page shows you.

If your radio does this well, there's been more done to it than simply beaking a circuit and inserting a potentiometer as shown.

And that's the "genius" part of it that isn't posted, retaining full swing at a low carrier.

Not as simple as it looks.

73
 
Vari Pwr and Dead key...

Hello,
I have missed most of this post til now,
Lets see if I can help..

The Mod states that the Vari Pwr will affect the AM and SSB key.
The Mod does not affect the Modulated signal on AM .. If the radio was peaked and the AMC was left untouched you need to adj the AMC level to affect the Modulated signal.
If the AM Mic Gain mod was added, the AMC control will still work.

The AM power controls Vr107 and Vr113 should be adjusted to a proper High pwr level, the vari pwr control will adjust that dead key down to less than 1W.

The SSB output level should be controllable due to the location of the mod[in the voltage divider network], but on a peaked radio it may not be variable or show much variation from peak. (meaning you wont get 0 to max like on AM )

I will have to investigate this a bit more.
I will and corrections will be noted on my site in the future..

Sorry I have not been on this board as much as in the past but it has been a busy year.
feel free to contact me by email ..

Rogerbird1 @ netscape.net (remove spaces)
 
That is cool RB, I just wasn't sure why it didn't change on SSB but, since you did the work and the tune that must be why.

Thanks again for the great work, I have two 250's and the one you worked on without a question out performs the other one. I will send that one to you someday also.
 

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