guys i am an old school guy from back in the day. i am setting my station back up and thought i would see what you guys thought. got a galaxy saturn hitting a jb150 hitting a d&a 1o tube brown faced phantom hitting a 2 kw floor model henry. hitting the phantom with about 3 watts swinging to about 90 and getting about 100 or so dead key swinging to about 750 or so with the phantom. then hitting the henry with that 100 dead key and getting about 200 to 300 dead key out of the henry and swinging to about 3kw. these numbers are on a dozy meter. what do you guys think about that? is it running the henry too hard? i have had the jb 150 and the phantom since about 1977 bought them both new.
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trying to get world wide again
- Thread starter 20poundhammer
- Start date
sounds like you're world wide all right. now just crank the D104 up and spin the mic gain and you be 10-8 and str8! 
Toll_Free
Well-Known Member
20 pounder.
There are a couple JB boxes with that nomenclature.
Since you have the one that does 120-150 watts, I'd say you have a low tube... Get that tube replaced, and use IT to drive the Henry.
OR, use the D & A on the LOW side with the RADIO as a driver into the Henry, when the going gets tough.
Hitting a pair of 500Zs with 700+ watts is looking for trouble.... I'm going to GUESS you haven't looked at the price of a pair of 3-500Zs lately... 20 years ago, we retubed the Henry's and Heathkits for 100 dollars FOR BOTH TUBES.
Today, the Amperex is over 300 dollars EACH. The CHEAPEST 500Z you'll find is Chinese, and over 100 dollars each, when purchased as matched sets.
If you REALLY want to hit that amplifier THAT hard, throw about 20-28 volts of bias into it... You NEED that much bias to get the tubes down.
IE, think of it this way, depending on the Henry you have, it's rated for 1200 to 2Kw PEP output with 100 watts of drive.
We will take the 1200 watts, and do the 'maths' from their.
100 watts in = 1200 out = 12 times multiplication.
Your 700 watt driver should push that Henry to 8 thousand, pep. I HIGHLY doubt you'll see that.
I'd hit it with no more than 300 watts PEP, and I'd do a bias mod FIRST.
OR, I'd leave it stock, with 4-7 volts of bias in it, and hit it with the BlackCat. With a JB150 (225-300 PEP depending on the tube), I can hold a thousand watts AVG on the Bird wattmeter... That equates to close to 2800 pep out...... Half the drive, same Pout.
If you have any other questions, please feel free to ask. That BlackCat makes a bitchen driver... For EITHER box... BUT, your IPA (intermediate power amplifier) is quite large for your 'pumphouse'....
And FYI, 20 years ago, 6 500Zs was bigstrappin. Guys are runnin 20,000 tubes now. Step up!!!
--Toll_Free
There are a couple JB boxes with that nomenclature.
Since you have the one that does 120-150 watts, I'd say you have a low tube... Get that tube replaced, and use IT to drive the Henry.
OR, use the D & A on the LOW side with the RADIO as a driver into the Henry, when the going gets tough.
Hitting a pair of 500Zs with 700+ watts is looking for trouble.... I'm going to GUESS you haven't looked at the price of a pair of 3-500Zs lately... 20 years ago, we retubed the Henry's and Heathkits for 100 dollars FOR BOTH TUBES.
Today, the Amperex is over 300 dollars EACH. The CHEAPEST 500Z you'll find is Chinese, and over 100 dollars each, when purchased as matched sets.
If you REALLY want to hit that amplifier THAT hard, throw about 20-28 volts of bias into it... You NEED that much bias to get the tubes down.
IE, think of it this way, depending on the Henry you have, it's rated for 1200 to 2Kw PEP output with 100 watts of drive.
We will take the 1200 watts, and do the 'maths' from their.
100 watts in = 1200 out = 12 times multiplication.
Your 700 watt driver should push that Henry to 8 thousand, pep. I HIGHLY doubt you'll see that.
I'd hit it with no more than 300 watts PEP, and I'd do a bias mod FIRST.
OR, I'd leave it stock, with 4-7 volts of bias in it, and hit it with the BlackCat. With a JB150 (225-300 PEP depending on the tube), I can hold a thousand watts AVG on the Bird wattmeter... That equates to close to 2800 pep out...... Half the drive, same Pout.
If you have any other questions, please feel free to ask. That BlackCat makes a bitchen driver... For EITHER box... BUT, your IPA (intermediate power amplifier) is quite large for your 'pumphouse'....
And FYI, 20 years ago, 6 500Zs was bigstrappin. Guys are runnin 20,000 tubes now. Step up!!!
--Toll_Free
Yeah... further to what Toll_Free just said, I would not hit that Henry with more than 150W PEP. More than that and you're over driving that amp. Most 3-500 amps are 13dB gain, or again of 20X. So, 100W PEP IN will deliver about 2000W PEP out. Some amps run higher B+ Voltages and can get more out. I'm assuming that Henry runs about 3300 VDC (typical). At that voltage, you should see about 2200W PEP with 100W drive.
On AM, everything changes. Assuming 2000 W PEP out, the most power out you can run on AM is 500W MAXIMUM!!!. More likely, 350W will be your maximum. That means just that - 350W maximum on your maximum swing! Any more than that and you are overdriving the amp and producing garbage, distortion, and a w-i-d-e signal. Wide=wasted power
A lot of hams run linears on AM, after their "rice-boxes" and run no more than 350W out. They sound clean like a broadcast station. The reason we recommend 350W maximum is due to the nature of an AM signal. A 100W AM carrier at 100% mudulation equals 400W PEP. (I.e.: the PEP value of an AM signal is four times the modulated output.) So, 350W PEP = 1400W PEP. This is well within the typical maximum spec of 3-500 tubes. You need the headroom to allow modulation peaks, otherwise you have severe distortion on the audio, the modulation sounds crunchy and fuzzy, and you're generating spurious trash everywhere, plus you're wasting power.
This 4:1 formula for AM applies to any linear, no matter the power output. If that linear does 300W PEP maximum, then the maximum AM modulated carrier would be 75W (max swing). If it does 100W PEP, then your maximum modulated carrier out would be 25W. This rule is sacrosanct. You break it at your peril, (and the complaints from your neighbors and other CB'ers!!!)
On AM, everything changes. Assuming 2000 W PEP out, the most power out you can run on AM is 500W MAXIMUM!!!. More likely, 350W will be your maximum. That means just that - 350W maximum on your maximum swing! Any more than that and you are overdriving the amp and producing garbage, distortion, and a w-i-d-e signal. Wide=wasted power
A lot of hams run linears on AM, after their "rice-boxes" and run no more than 350W out. They sound clean like a broadcast station. The reason we recommend 350W maximum is due to the nature of an AM signal. A 100W AM carrier at 100% mudulation equals 400W PEP. (I.e.: the PEP value of an AM signal is four times the modulated output.) So, 350W PEP = 1400W PEP. This is well within the typical maximum spec of 3-500 tubes. You need the headroom to allow modulation peaks, otherwise you have severe distortion on the audio, the modulation sounds crunchy and fuzzy, and you're generating spurious trash everywhere, plus you're wasting power.
This 4:1 formula for AM applies to any linear, no matter the power output. If that linear does 300W PEP maximum, then the maximum AM modulated carrier would be 75W (max swing). If it does 100W PEP, then your maximum modulated carrier out would be 25W. This rule is sacrosanct. You break it at your peril, (and the complaints from your neighbors and other CB'ers!!!)
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Toll_Free
Well-Known Member
Sorry, va3, but you run a 375 watt carrier, and 100 percent modulate it, you're running 1500 watts PEAK... THAT's your swing.
I second everything else.
--Toll_Free
I second everything else.
--Toll_Free
Yup. That's basically what I said. I just used 350W as an example, you used 375. Same thing in the end. By regulation, U.S. amateurs are restricted to 375W of AM carrier, so as to not exceed 1500W PEP carrrier. It's a regulation that makes no sense.
Up here, we can run 1000W input. With an efficient PA stage that might deliver 700 - 800 W output. We have guys here (like me), that are running ex-broadcast transmitters on the ham bands, running 1000W out at 125% positive modulation. That's 5000W PEP. Nobody cares. I guess the government up here figures that if you can run one of those boxes, you must know what you're doing. OTOH, I know of lots of U.S. hams doing precisely the same thing. Nobody's been busted yet! well guys that is some great info! i guess i should have stated this is going to be ran on 27 mhz for mauldropping cb action lol. i am looking for the best set up for the best performance with the least amout of trouble. the black cat driver i have would never do over about 100 to 110 watts and i got it for the driver for the d&a back in the day. after i came across the henry and set up my stuff like that it had some awsome modulation i must say lol. i havent had any problems out of the equipment like that back when i was running it. i havent been on the band since about 2001 or 2002 and i know things change. so any more recomendations from you guys?
Toll_Free
Well-Known Member
You don't get a modulation increase with ANY amplifier.... Unless it's MODULATED.
And a MODULATOR is not something that will MODULATE your linear.
All the "loudness" people strive for on 11 meters has a technical term, it's called Intermodulation Distortion.
--Toll_Free
And a MODULATOR is not something that will MODULATE your linear.
All the "loudness" people strive for on 11 meters has a technical term, it's called Intermodulation Distortion.
--Toll_Free
The last guy that I knew running a phantom, was transmitting just as well 20 channels up or down. LOL. No splatter or garbage there. Lol.
WHAT!!!!????
I'm shocked! SHOCKED I tell you!!!! (Yeah, we got that. I figure if yer going to do that, do it right!!! :laughWell, you won't compete with the big boys on "Da Bowl", but you'll hold your own.
You can run infinitely positive modulation, but only 100% negative. As soon as you hit 100% negative, you will splatter. 300% positive peaks won't splatter, but 300% negative will!!! In fact with 300% negative peaks (impossible BTW; 100% negative is the most you can go), you would probably damage your transmitter.
The "NPC" mod does just that - stretches the positive peaks over 100% positive, while keeping the negative peaks at 99%. Hams have been doing that since 1946. Back then they ran something called "Ultramodulation" and even something called "Supermodulation". These were attempts to run super-high levels of modulation, while keeping the negatives at just under 100%. One famous ham, W3PHL, ran 20,000 watts of audio, modulating a 600W carrier!!! Loud? I can't even begin to describe it. The FCC eventually shut him down on a technicality!
Toll_Free
Well-Known Member
Ed,
Was that you that checked into the AMI net from .ca this Wednesday?
Don't have the link tuner up, so can only run 100 watts here into the remote tuna, but nice signal into central cali, if that was you on 80.
--Toll_Free
Was that you that checked into the AMI net from .ca this Wednesday?
Don't have the link tuner up, so can only run 100 watts here into the remote tuna, but nice signal into central cali, if that was you on 80.
--Toll_Free
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@ ButtFuzz:Please advise me to what is a good replacement mic for my SR-497HPC... Answer: 497 is "wired like Cobra", so many choices available. That radio does not need a power mic, so purchase a stock "coffin style" mic with a decent cord, like the ones that Astatic uses. The Superstar DM-507 is my go-to. https://www.ebay.com/itm/3050474478...adANq91JSiEEnz8EGqPJRBloTgEyaVsBoCtoMQAvD_BwE $12.99 + .99 cent shipping.
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