Damn, dude...I ain't seen tubes like that in forever!! I'm the tech guy in my area, and I hardly ever see tubes anymore. Every now and then someone will bring me a tube unit that they picked up at garage sales and stuff. Tube linears are getting really rare these days.
well here in the big city of Detroit all matter of tubes (especially big tubes) is still very popular. 4cx250's, 3-500z, 4-1000, 4-800, GS35 etc. I just saw a Johnboy with 4 4cx800 go on Ebay for $2600
tramdr WOW. It's really cool that there are still old tube linear amps out there. I just recently fixed an old Palomar 300A for a guy here in town...had to order some tubes online, 6KD6's if I remember right...and they were not cheap...lol. Got his amp back up and running like a champ again though. I miss the old tube amps...I still think that they were/are better in many ways than the transistor amps of today, they seemed to have a lot more gain and output power.
Gun Slinger, there's a company called Econco. They rebuild steel tubes. Big ones. I had 2 -3CX3000A7' tubes and was driving them with a 16 pill. It arced through a piece of Andrew 7/8 Heliax. I had 4 truck Cased Leece Nevilles to power the amps high voltage. The other 4, where DC. External adjustable voltage One was the stock alternator. I learned that from experience, not to hook up anything to the stock electrical system. Then, the remainder 3, 2 were 18 volts for the driver amps. The last one was 12 volts for misc switch gear and whatever. Blue Ghost made the rack and the crank pully. Transistor boxes are 4 2SC2879 's driving 16 of the same transistors , except I'm running them on 18 volts. That then drove the 2 Triodes with the solid state Class C modulators. 4 into 16 into 2 3CX3000A7 tubes. It would peg a Bird 43 with the 10 KW slug easy. I borrowed a friend's 4305A, and I put it in the corner also. With 4 power supplies for B+ and 9 volts on the filliment. Which is fine with me. Never had a problem. That box was doing 25,000 + . After the 7/8, Andrew coax incident, I switched to a very flexible and big feed line from a submarine ? Yea, me too. Got it from a guy that sells parts. I miss it. I loved pulling up to a boom boom car and keying down hard. They loved me. Then I got married and no more keydown suburban. 4 of those tiny toys I could wack whoever was running them. I love amplifiers RF and audio. Tubes for Audio.
Looks like something for testing ? A test amp board. My first tube amp had 1 driving 4, PL8295 radial beam Pentodes. I got 23 of them at an estate sale. 20.00 . The guy who passed away and his stuff was sold. As soon as I saw them, I bolted over and bought them. The man was a ham radio operator and an engineer. He had all kinds of stuff that was desirable to builders.
I've got a Dentron GLA1000 with 4 mixed 6LQ6/6JE6C tubes. On 10 meters I can get 300 watts out of it with 75 exciter watts from my Yaesu. On 40 and 80 meters it will do 500 watts same exciter drive. Any more exciter drive it still does the same amount. So I don't drive it any harder. I was wondering if it would cost efficient to have it retubed with one 4CX250B tube? And still get the same if not better output power? Maybe even be more broad banded and not loose power on 10 meters. I've also got the cheaper twin version Ameritron AL-84. The tubes in the AL-84 are weak @ 200 watts and it blown the 8 amp fuse. Last time I tested it.
What's the proper way to adjust the input tune on my palomar 300a. When in low my radio shows high swr about a 3. On high power it shows about 1.3. I just don't know how to adjust the input tune pot's on the bottom side of the amp. Thanks in advance
I run a CCS1 (the conduction cooled version of the 4CX250) on VHF, I am using a regulated screen supply of my own design that can source and sink current (300v). I am running 2300v on the HV (off load) and a heavily swamped grid. I don't have the IMD figures but it seems to solicit reports on air where people have said "I can't believe that is a tetrode". With the poor transmit performance of many modern rigs I don't think the 4CX250 is the villain it is portrayed as.
I was watching your video and I seen the modulator you're running and I couldn't believe my eyes when I bought my Browning Golden Eagle it came with that same modulator except mines got a chrome handle on top and a meter along with it identical to yours I wonder if you could give me a little info on it it would be appreciated please reply thank you
I lucked up and found a 6 tube Elite booster actually was left in a house that I was renting the man left it behind .it's an elite doesn't have any numbers someone has added a fan would love to know how much power is pushing.
Why do people keep asking me questions about the build on this. I did not build this. John Boy / Tennessee walker is a well known builder who built this along with many many more of this type. I do not know him. I do not know what CFM he used, etc. I got this in a trade and it didn't work, hence I repaired it. BTW there was a bigger one on Ebay (it ended already) where a similar John Boy 2 piece like this but it had 4 4cx800's went for $2500
I had sold it and shipped it during the peak of Covid and Fedex looked like they played football with it. I got it back. but it is beat up and not working. I also am done with shipping big amps. Lost too much money doing that.
thats awsome , you do great work keep it up. i try to work on amps also but started 2 years ago im a few pay grades below. have all test equiptment just need to get theory down. do better on amps than radios go fiqure.
those 4cx250's are very dirty imd tubes,,,lol but ...at least your output correspond to the capability of the 4 tubes. run them at 900 watt and they will last forever + be way cleaner on imd's. well done on the quick fix
+Lucky Dube in RC I have heard that 4cx250's are dirty IMD wise, but IMHO, you also have to look at the gain. For operators with low drive exciters, I have always wondered what would the IMD specs be of an operator using a clean driver going into a clean high drive amp vs the specs of the 'dirty' single stage 4cx250b amp used right. IMHO for CB'ers that use transistor driver amps or overdriven badly tuned amps, I think the single 4cx250b will be cleaner in most cases than driver amp / final amp setups.
They are not anywhere near as bad as they are portrayed, much of it is down to poorly regulated screen supplies etc. Eimacs own application data has a poor bias circuit.
They do the watts but they are very cheaply built, use no safety circuitry and takes short cuts, not to mention what the Hams and haters think of an amp built for 11 meters only.
Cool box now, well done.
Good to hear from you again.
I really like your videos,Tram Dr.,ALWAYS VERY Thorough.Thankyou,Sir.Traindriver,Raleigh,NC..
Damn, dude...I ain't seen tubes like that in forever!! I'm the tech guy in my area, and I hardly ever see tubes anymore. Every now and then someone will bring me a tube unit that they picked up at garage sales and stuff. Tube linears are getting really rare these days.
well here in the big city of Detroit all matter of tubes (especially big tubes) is still very popular. 4cx250's, 3-500z, 4-1000, 4-800, GS35 etc. I just saw a Johnboy with 4 4cx800 go on Ebay for $2600
tramdr
WOW. It's really cool that there are still old tube linear amps out there. I just recently fixed an old Palomar 300A for a guy here in town...had to order some tubes online, 6KD6's if I remember right...and they were not cheap...lol. Got his amp back up and running like a champ again though. I miss the old tube amps...I still think that they were/are better in many ways than the transistor amps of today, they seemed to have a lot more gain and output power.
I've got several old tube amps. Found them at a pawn shop.
A couple need to be looked at. No one wants to mess with them out here where I am!
Gun Slinger, there's a company called Econco. They rebuild steel tubes. Big ones. I had 2 -3CX3000A7' tubes and was driving them with a 16 pill. It arced through a piece of Andrew 7/8 Heliax.
I had 4 truck Cased Leece Nevilles to power the amps high voltage. The other 4, where DC. External adjustable voltage
One was the stock alternator. I learned that from experience, not to hook up anything to the stock electrical system. Then, the remainder 3, 2 were 18 volts for the driver amps. The last one was 12 volts for misc switch gear and whatever.
Blue Ghost made the rack and the crank pully.
Transistor boxes are 4 2SC2879 's driving 16 of the same transistors , except I'm running them on 18 volts. That then drove the 2 Triodes with the solid state Class C modulators. 4 into 16 into 2 3CX3000A7 tubes. It would peg a Bird 43 with the 10 KW slug easy. I borrowed a friend's 4305A, and I put it in the corner also. With 4 power supplies for B+ and 9 volts on the filliment. Which is fine with me. Never had a problem. That box was doing 25,000 + . After the 7/8, Andrew coax incident, I switched to a very flexible and big feed line from a submarine ? Yea, me too. Got it from a guy that sells parts. I miss it. I loved pulling up to a boom boom car and keying down hard. They loved me. Then I got married and no more keydown suburban. 4 of those tiny toys I could wack whoever was running them. I love amplifiers RF and audio. Tubes for Audio.
Looks like something for testing ? A test amp board. My first tube amp had 1 driving 4, PL8295 radial beam
Pentodes. I got 23 of them at an estate sale. 20.00 . The guy who passed away and his stuff was sold. As soon as I saw them, I bolted over and bought them. The man was a ham radio operator and an engineer. He had all kinds of stuff that was desirable to builders.
I've got a Dentron GLA1000 with 4 mixed 6LQ6/6JE6C tubes. On 10 meters I can get 300 watts out of it with 75 exciter watts from my Yaesu. On 40 and 80 meters it will do 500 watts same exciter drive. Any more exciter drive it still does the same amount. So I don't drive it any harder. I was wondering if it would cost efficient to have it retubed with one 4CX250B tube? And still get the same if not better output power? Maybe even be more broad banded and not loose power on 10 meters. I've also got the cheaper twin version Ameritron AL-84. The tubes in the AL-84 are weak @ 200 watts and it blown the 8 amp fuse. Last time I tested it.
Nope. Get better tubes or just sell them and get a bigger amp.
thanks for the great advice, those are two things i dont have. i will get them thanks very much for taking time to let me know thanks again . mike
You're the watt meter king.
Awesome job noname your a beast
Thank You!
good to see you back'
73's
Hello sir are you still working on rf amps 73 thanks for the time...love this amp ...❤
Sorry, no.
What's the proper way to adjust the input tune on my palomar 300a. When in low my radio shows high swr about a 3. On high power it shows about 1.3. I just don't know how to adjust the input tune pot's on the bottom side of the amp. Thanks in advance
You must not have watched THIS video..... th-cam.com/video/S0Jvd-NtkxA/w-d-xo.html
Nice, informative video as always
Could you say something about the applied neutralization (assuming a grounding cathode) and the cooling air flow ( CFM ) ?
I run a CCS1 (the conduction cooled version of the 4CX250) on VHF, I am using a regulated screen supply of my own design that can source and sink current (300v). I am running 2300v on the HV (off load) and a heavily swamped grid. I don't have the IMD figures but it seems to solicit reports on air where people have said "I can't believe that is a tetrode". With the poor transmit performance of many modern rigs I don't think the 4CX250 is the villain it is portrayed as.
+g0fvt especially compared to solid state.
Those 4CX250 and many others 220, 230' tubes are fantastic tubes, very versatile. I've seen them used in military aircraft RF equipment.
tramdr !!11
I was watching your video and I seen the modulator you're running and I couldn't believe my eyes when I bought my Browning Golden Eagle it came with that same modulator except mines got a chrome handle on top and a meter along with it identical to yours I wonder if you could give me a little info on it it would be appreciated please reply thank you
I don't know of one with a chrome handle on top. Maybe a non factory mod? Pics might help.
I lucked up and found a 6 tube Elite booster actually was left in a house that I was renting the man left it behind .it's an elite doesn't have any numbers someone has added a fan would love to know how much power is pushing.
Those are cool. I never had one.
where did you get your tube sockets and the pats to hold tubes down
Why do people keep asking me questions about the build on this. I did not build this. John Boy / Tennessee walker is a well known builder who built this along with many many more of this type. I do not know him. I do not know what CFM he used, etc. I got this in a trade and it didn't work, hence I repaired it. BTW there was a bigger one on Ebay (it ended already) where a similar John Boy 2 piece like this but it had 4 4cx800's went for $2500
Nice job bro
What is the plate voltage of that?
2350
How much you want for that the John-Boy full toolbar 250b
I had sold it and shipped it during the peak of Covid and Fedex looked like they played football with it. I got it back. but it is beat up and not working. I also am done with shipping big amps. Lost too much money doing that.
I would like to have one of these
you are in good company.
could you do this again? one of these came across my path.
do what again, fix one? Shipping back and forth would probably be $100 each way unless you are local. Plus parts and labor....it can get very costly.
Hey Tram DR. Do you have anything like this right now?
I recently sold almost all the amps I had. This is the only legal limit amp I have left. th-cam.com/video/2wYBK2Lun_A/w-d-xo.html
@@tramdr how much are you asking for?
thays what im sayin...look at that swing heck yeah..
That's a mean amp!
@@tramdr heck yeah man
Are you keeping that for your retirement days?
Nope.
Are you still fixing amps? Cause I have a dual 250b that needs some tlc!!!!!!
I got it and it’s not working right.....
I'm a mud duck who only fixes my own.
I only roll my own. If you can use a meter and solder, I might could help you with it.
tramdr thanks bud I how we do this you want my email address?
you can email me at Tramdr@yahoo.com
I will thanks!!!!
Nice!
Thanks!
I have a Pride 300 with a single 250B
Where can I find a transformer like the one in the PS.? Great vid! More vid’s please!!!!
Empire State
73’s
Gettin up and gettin out!!
Have any 2/3 tubers?
No
damn that thing kicks ass
Still got it for sale ronald?
yep
What did you want for it..I know you said you had a buddy na
Barrowing it.
How can I get ahold of you bud?
PM (personal message) me
tramdr I don’t know how to pm thru here but mi info is there bud!!!!
thats awsome , you do great work keep it up. i try to work on amps also but started 2 years ago im a few pay grades below. have all test equiptment just need to get theory down. do better on amps than radios go fiqure.
+mike canton Bill Orr manual, using a grid dip meter manual and using an antenna analyzer manual are big helps
Very nice..
Maybe ad 4..8930!!!
did you sell this
+Geronemo Bauer No, still have it
+tramdr what you asking for it. How much to ship it
+Geronemo Bauer $1400 Ship it to where? I try to charge actual but USA only.
it walks the dog 73's slimjim119 in Kingston,Ontario.Canada
I know you have a lot of knowledge about them Though
those 4cx250's are very dirty imd tubes,,,lol but ...at least your output correspond to the capability of the 4 tubes.
run them at 900 watt and they will last forever + be way cleaner on imd's.
well done on the quick fix
+Lucky Dube in RC I have heard that 4cx250's are dirty IMD wise, but IMHO, you also have to look at the gain. For operators with low drive exciters, I have always wondered what would the IMD specs be of an operator using a clean driver going into a clean high drive amp vs the specs of the 'dirty' single stage 4cx250b amp used right. IMHO for CB'ers that use transistor driver amps or overdriven badly tuned amps, I think the single 4cx250b will be cleaner in most cases than driver amp / final amp setups.
They are not anywhere near as bad as they are portrayed, much of it is down to poorly regulated screen supplies etc. Eimacs own application data has a poor bias circuit.
How much?
+Geronemo Bauer $1400 firm.
if you have this amp I'm interested to buy
I have it but am asking 1200 for it.
my real email is tramdr@yahoo.com
You just not going to give me a phone call to answer my questions? WHY?
I get many who have lots of questions so I normally prefer just emails. Tramdr at Yahoo.com
I have a one tube (same tube) 2 meter amp!
I have never had one but why do people talk bad about these amps?
They do the watts but they are very cheaply built, use no safety circuitry and takes short cuts, not to mention what the Hams and haters think of an amp built for 11 meters only.
SWEET!!!!
Mighty Fine Junk LOL
LOL
That's a big chunk of iron.
all these amp doctors always show no carrier and all swing. I can make a bird 43 swing awesome in sideband.
umm ok good for you
My
My My My
STOP WHISTLING INTO THE DAMN THING..
WHY NOT?