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Over the years I've collected parts to build an amplifier. Life got in the way during most those years but now I find myself with the time and ambition to build an amplifier for my boatanchors.
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As far as bottles are concerned I have a bunch of 813s a 3-400Z,. couple of 4-400s and of course the usual 811s, 807s, 6146s........Got plenty of iron for a power supply up to 3kv.
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Need some direction as to which way to go.? I operate 40 thru 10. Have a soft spot for AM. (yes I'm old) but do CW and SSB.
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Finishing up a 350 watt modulator.
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OR should I forget all this stuff sell it and buy an amplifier.
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don |
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开云体育Don, ????????? You have some mighty fine tubes to make up a bunch of nice amplifiers. My old mentor, Eric, WA4VVI(SK) would run 4 813’s at 4KV! I have an RCA SB-1K Radiomarine amp that uses 3-400Zs and lazily will do a 1KW at 2800VDC. 4-400s you could tie the grids together and with a little extra drive, make a fine amp. So your possibilities are endless. Yes, I run AM also, (my primary mode!). ? Mod-U-Lator, Mike(y)/W3SLK ? ? ? From: [email protected] [mailto:[email protected]] On Behalf Of kc1at via groups.io ? Over the years I've collected parts to build an amplifier. Life got in the way during most those years but now I find myself with the time and ambition to build an amplifier for my boatanchors. ? As far as bottles are concerned I have a bunch of 813s a 3-400Z,. couple of 4-400s and of course the usual 811s, 807s, 6146s........Got plenty of iron for a power supply up to 3kv. ? Need some direction as to which way to go.? I operate 40 thru 10. Have a soft spot for AM. (yes I'm old) but do CW and SSB. ? Finishing up a 350 watt modulator. ? OR should I forget all this stuff sell it and buy an amplifier. ? don |
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I would sell all your tubes and buy 1? ?8877.? Just my opinion.
On Tuesday, February 4, 2025 at 06:36:35 AM EST, kc1at via groups.io <kc1at@...> wrote:
Over the years I've collected parts to build an amplifier. Life got in the way during most those years but now I find myself with the time and ambition to build an amplifier for my boatanchors.
?
As far as bottles are concerned I have a bunch of 813s a 3-400Z,. couple of 4-400s and of course the usual 811s, 807s, 6146s........Got plenty of iron for a power supply up to 3kv.
?
Need some direction as to which way to go.? I operate 40 thru 10. Have a soft spot for AM. (yes I'm old) but do CW and SSB.
?
Finishing up a 350 watt modulator.
?
OR should I forget all this stuff sell it and buy an amplifier.
?
don
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开云体育
Are you planning on using the modulator with this amplifier?? ?If so a Single 4-400 will do 550 to 600 carrier and would be a good match for that 350-watt modulator for AM. It's a simple circuit.? With added Bias, you can run it in AB and use it on SSB.
C
From: [email protected] <[email protected]> on behalf of mike repinski via groups.io <mikflathead@...>
Sent: Tuesday, February 4, 2025 7:55 AM To: [email protected] <[email protected]> Subject: Re: [ham-amplifiers] Dilemma ?
I would sell all your tubes and buy 1? ?8877.? Just my opinion.
On Tuesday, February 4, 2025 at 06:36:35 AM EST, kc1at via groups.io <kc1at@...> wrote:
Over the years I've collected parts to build an amplifier. Life got in the way during most those years but now I find myself with the time and ambition to build an amplifier for my boatanchors.
?
As far as bottles are concerned I have a bunch of 813s a 3-400Z,. couple of 4-400s and of course the usual 811s, 807s, 6146s........Got plenty of iron for a power supply up to 3kv.
?
Need some direction as to which way to go.? I operate 40 thru 10. Have a soft spot for AM. (yes I'm old) but do CW and SSB.
?
Finishing up a 350 watt modulator.
?
OR should I forget all this stuff sell it and buy an amplifier.
?
don
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开云体育Grid drive one 4-400 with bias and screen voltage.? Then you can run Class C for plate modulation and bias it for AB1 or AB2 operation for SSB amplifier mode. ? A Johnson ranger or similar power level ?“boatanchor” would make an ideal driver for the Class C operation.? Lots of schematics available in earlier ARRL publications for such a set up. I think there was a 4-400A amp in several of the ARRL handbooks from the 1960’s. ? 813’s get squirrely on 15M and above and can be tamed but efficiency drops a bit. ? What are the modulator tubes and which modulation transformer are you going to use? ? I’ve built several AM rigs in the past ten years and have pictures of them on my QRZ.com page.? Check out the 4-400A rig I designed and built.? Also the 813 rig. ? -Chuck K1KW ? From: [email protected] [mailto:[email protected]] On Behalf Of kc1at via groups.io ? Over the years I've collected parts to build an amplifier. Life got in the way during most those years but now I find myself with the time and ambition to build an amplifier for my boatanchors. ? As far as bottles are concerned I have a bunch of 813s a 3-400Z,. couple of 4-400s and of course the usual 811s, 807s, 6146s........Got plenty of iron for a power supply up to 3kv. ? Need some direction as to which way to go.? I operate 40 thru 10. Have a soft spot for AM. (yes I'm old) but do CW and SSB. ? Finishing up a 350 watt modulator. ? OR should I forget all this stuff sell it and buy an amplifier. ? don |
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开云体育
Hey Chuck.? Have not had a QSO is a long time. Where are you hanging out these days on AM?
W7WRX
From: [email protected] <[email protected]> on behalf of Chuck Neal via groups.io <cdoneal@...>
Sent: Tuesday, February 4, 2025 9:38 AM To: [email protected] <[email protected]> Subject: Re: [ham-amplifiers] Dilemma ?
Grid drive one 4-400 with bias and screen voltage.? Then you can run Class C for plate modulation and bias it for AB1 or AB2 operation for SSB amplifier mode. ? A Johnson ranger or similar power level ?“boatanchor” would make an ideal driver for the Class C operation.? Lots of schematics available in earlier ARRL publications for such a set up. I think there was a 4-400A amp in several of the ARRL handbooks from the 1960’s. ? 813’s get squirrely on 15M and above and can be tamed but efficiency drops a bit. ? What are the modulator tubes and which modulation transformer are you going to use? ? I’ve built several AM rigs in the past ten years and have pictures of them on my QRZ.com page.? Check out the 4-400A rig I designed and built.? Also the 813 rig. ? -Chuck K1KW ? From: [email protected] [mailto:[email protected]]
On Behalf Of kc1at via groups.io ? Over the years I've collected parts to build an amplifier. Life got in the way during most those years but now I find myself with the time and ambition to build an amplifier for my boatanchors. ? As far as bottles are concerned I have a bunch of 813s a 3-400Z,. couple of 4-400s and of course the usual 811s, 807s, 6146s........Got plenty of iron for a power supply up to 3kv. ? Need some direction as to which way to go.? I operate 40 thru 10. Have a soft spot for AM. (yes I'm old) but do CW and SSB. ? Finishing up a 350 watt modulator. ? OR should I forget all this stuff sell it and buy an amplifier. ? don |
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开云体育Dear Don, (et al, of course), ? You are going through a time very similar to my own experiences. I was hot and heavy on HB QRO tube-type amps, and built them one after another. ? It was necessary to put RF aside for a while, and now I’m struggling to get it on track. ? One of my winter projects easy to handle is the cleanup and refurbishment of a Heathkit SB-220 linear amplifier. Very little machining, a great deal of cleanup, some soldering, some painting: It is a wide-band project, and easy to pick up again after being put away. ? If you ever built Heathkits as a younger person and enjoyed yourself, you will find that same enthusiasm once again, but this time you have the Internet full of ideas, and all your years of experience and maturity to apply. ? Hal Mandel W4HBM |
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开云体育Addendum: ? I’ve built many rigs using Eimac tubes from the 4-65A to 4-1000A’s to ceramics like the 4CX1500A (Not to be confused with the 4cx1500B).? One rig was a pair of 3CX1200A7’s modulating a single 4CX1500A.? A cool 2.5 KW out using 5KW broadcast iron from A Collins BC transmitter.? Long gone to a W3 who doesn’t use it. ? Need any design help?? I remember Reed Brandon from years ago helping me out. ? -Chuck K1KW ? From: [email protected] [mailto:[email protected]] On Behalf Of Chuck Neal via groups.io
Sent: Tuesday, February 04, 2025 11:39 AM To: [email protected] Subject: Re: [ham-amplifiers] Dilemma ? Grid drive one 4-400 with bias and screen voltage.? Then you can run Class C for plate modulation and bias it for AB1 or AB2 operation for SSB amplifier mode. ? A Johnson ranger or similar power level ?“boatanchor” would make an ideal driver for the Class C operation.? Lots of schematics available in earlier ARRL publications for such a set up. I think there was a 4-400A amp in several of the ARRL handbooks from the 1960’s. ? 813’s get squirrely on 15M and above and can be tamed but efficiency drops a bit. ? What are the modulator tubes and which modulation transformer are you going to use? ? I’ve built several AM rigs in the past ten years and have pictures of them on my QRZ.com page.? Check out the 4-400A rig I designed and built.? Also the 813 rig. ? -Chuck K1KW ? From: [email protected] [mailto:[email protected]] On Behalf Of kc1at via groups.io ? Over the years I've collected parts to build an amplifier. Life got in the way during most those years but now I find myself with the time and ambition to build an amplifier for my boatanchors. ? As far as bottles are concerned I have a bunch of 813s a 3-400Z,. couple of 4-400s and of course the usual 811s, 807s, 6146s........Got plenty of iron for a power supply up to 3kv. ? Need some direction as to which way to go.? I operate 40 thru 10. Have a soft spot for AM. (yes I'm old) but do CW and SSB. ? Finishing up a 350 watt modulator. ? OR should I forget all this stuff sell it and buy an amplifier. ? don ?
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开云体育Well, not much on the air these days, mostly on 160M, 75M, and sometimes on 40M in the so called “AM windows” ? Spending much more time on other infinite money sinks like olde cars and astronomy. ? More hobbies as I get older and things I always wanted to do as a kid but couldn’t afford…now I can.. ? AS my father said, “I came into this world penniless, and I’m leaving it that way”? ??I’m working on that premise! ? -Chuck K1KW ? From: [email protected] [mailto:[email protected]] On Behalf Of W7WRX
Sent: Tuesday, February 04, 2025 12:31 PM To: [email protected] Subject: Re: [ham-amplifiers] Dilemma ? Hey Chuck.? Have not had a QSO is a long time. Where are you hanging out these days on AM? ? W7WRX From: [email protected] <[email protected]> on behalf of Chuck Neal via groups.io <cdoneal@...> ? Grid drive one 4-400 with bias and screen voltage.? Then you can run Class C for plate modulation and bias it for AB1 or AB2 operation for SSB amplifier mode. ? A Johnson ranger or similar power level ?“boatanchor” would make an ideal driver for the Class C operation.? Lots of schematics available in earlier ARRL publications for such a set up. I think there was a 4-400A amp in several of the ARRL handbooks from the 1960’s. ? 813’s get squirrely on 15M and above and can be tamed but efficiency drops a bit. ? What are the modulator tubes and which modulation transformer are you going to use? ? I’ve built several AM rigs in the past ten years and have pictures of them on my QRZ.com page.? Check out the 4-400A rig I designed and built.? Also the 813 rig. ? -Chuck K1KW ? From: [email protected] [mailto:[email protected]] On Behalf Of kc1at via groups.io ? Over the years I've collected parts to build an amplifier. Life got in the way during most those years but now I find myself with the time and ambition to build an amplifier for my boatanchors. ? As far as bottles are concerned I have a bunch of 813s a 3-400Z,. couple of 4-400s and of course the usual 811s, 807s, 6146s........Got plenty of iron for a power supply up to 3kv. ? Need some direction as to which way to go.? I operate 40 thru 10. Have a soft spot for AM. (yes I'm old) but do CW and SSB. ? Finishing up a 350 watt modulator. ? OR should I forget all this stuff sell it and buy an amplifier. ? don ?
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开云体育
Sounds good.? I have a HB rig with two 4-400s modulated by 304TLs.? It runs 10 to 160.? I have had it on 10 and 20 recently. Through a 4 elment mosley. Over 300 contacts on 10-meter AM. If you want to have a QSO sometime, that would be great!? ?
C
From: [email protected] <[email protected]> on behalf of Chuck Neal via groups.io <cdoneal@...>
Sent: Tuesday, February 4, 2025 2:57 PM To: [email protected] <[email protected]> Subject: Re: [ham-amplifiers] Dilemma ?
Well, not much on the air these days, mostly on 160M, 75M, and sometimes on 40M in the so called “AM windows” ? Spending much more time on other infinite money sinks like olde cars and astronomy. ? More hobbies as I get older and things I always wanted to do as a kid but couldn’t afford…now I can.. ? AS my father said, “I came into this world penniless, and I’m leaving it that way”? ??I’m working on that premise! ? -Chuck K1KW ? From: [email protected] [mailto:[email protected]]
On Behalf Of W7WRX ? Hey Chuck.? Have not had a QSO is a long time. Where are you hanging out these days on AM? ? W7WRX From:
[email protected] <[email protected]> on behalf of Chuck Neal via groups.io <cdoneal@...> ? Grid drive one 4-400 with bias and screen voltage.? Then you can run Class C for plate modulation and bias it for AB1 or AB2 operation for SSB amplifier mode. ? A Johnson ranger or similar power level ?“boatanchor” would make an ideal driver for the Class C operation.? Lots of schematics available in earlier ARRL publications for such a set up. I think there was a 4-400A amp in several of the ARRL handbooks from the 1960’s. ? 813’s get squirrely on 15M and above and can be tamed but efficiency drops a bit. ? What are the modulator tubes and which modulation transformer are you going to use? ? I’ve built several AM rigs in the past ten years and have pictures of them on my QRZ.com page.? Check out the 4-400A rig I designed and built.? Also the 813 rig. ? -Chuck K1KW ? From:
[email protected]
[mailto:[email protected]] On Behalf Of kc1at via groups.io ? Over the years I've collected parts to build an amplifier. Life got in the way during most those years but now I find myself with the time and ambition to build an amplifier for my boatanchors. ? As far as bottles are concerned I have a bunch of 813s a 3-400Z,. couple of 4-400s and of course the usual 811s, 807s, 6146s........Got plenty of iron for a power supply up to 3kv. ? Need some direction as to which way to go.? I operate 40 thru 10. Have a soft spot for AM. (yes I'm old) but do CW and SSB. ? Finishing up a 350 watt modulator. ? OR should I forget all this stuff sell it and buy an amplifier. ? don ?
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WOW....thanks so much for the input. Let me try to answer some of the questions
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Oops....its not a 350 watt modulator its a 300 watts. The thing is a monster. Has 4 - 12au7s into a pair of 6146's then into a pair of 6080s then the pair of 811s into a CVM-4. Can't figure out the 12AU7s. Lots of components missing or dead ended. I'll probably just make a new front end for it. Seems like an over kill to me.
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truth is I've been leaning towards the 4-400 with the 813s as a back up
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Can drive it with my 32v3. (one of 3) That's another disease i have "Collins stuff. "
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Let me drag out my 4-400 schematics that I've collected over the last year or so.
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don |
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开云体育
I would rip all the front-end tubes out and drive it with a 10W TOA amplifier. You can get these cheap on ebay and other websites.? $20 to $30 bucks. They have 4/8 and a 70v output with balanced and unbalanced and a Mic input. These work great to drive a pair
of modulators.? They also have bass and treble.? I use several here for that purpose.
The 813s as Chuck said, wont play well on higher bands. I would not use those. A 4-400 single is the way to go here.? You can modulate the screen with a Dropping resistor off the plate.? No screen supply.? ? You could use the 813s as modulators though!
Technically you won't even need a bias supply for the final. If you build a simple sequencer with a few relays, Diodes between the coils and caps to set delay.? You can ensure Drive appears on the 4-400 before its keyed with B plus.? Set drive to -183 volts
using a meter and a choke right to the grid.? This will be 10 to 12 MA.??
You could Grid leak it, OR build an adjustable bias supply with negative -75 to - 175 adjustability. I would not bother. One of my rigs has been running 20 years with No Bias.? It has a simple over current relay.? If drive where to disappear, it just trips.
A single will truck along at 500 to 600 W carrier No problem.
C
From: [email protected] <[email protected]> on behalf of kc1at via groups.io <kc1at@...>
Sent: Wednesday, February 5, 2025 5:28 AM To: [email protected] <[email protected]> Subject: Re: [ham-amplifiers] Dilemma ?
WOW....thanks so much for the input. Let me try to answer some of the questions
?
Oops....its not a 350 watt modulator its a 300 watts. The thing is a monster. Has 4 - 12au7s into a pair of 6146's then into a pair of 6080s then the pair of 811s into a CVM-4. Can't figure out the 12AU7s. Lots of components missing or dead ended. I'll
probably just make a new front end for it. Seems like an over kill to me.
?
truth is I've been leaning towards the 4-400 with the 813s as a back up
?
Can drive it with my 32v3. (one of 3) That's another disease i have "Collins stuff. "
?
Let me drag out my 4-400 schematics that I've collected over the last year or so.
?
don
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Thats what I'm leaning towards now. Scrap the input with all those 12AU7s and do something else. Reverse engineering that circuit seems fruitless . Not sure it even worked when built.
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Took a look at those TOA amps. I had no idea there were so many of them. Found a Bogen amp in my junk box. also has a 4-8 and 70.7 output with a cheap 4 band equalizer. Gonna drag that out to see if it has any hope of working.
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Going into my iron now to see if I can support? a single 4-400.
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thanks everyone for the help
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don |
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开云体育Don, ????????? I’m not sure if you know this, but you can use the 70.7V output to drive a 600Ω input. 5K/10KΩ P-P to 600Ω transformers are usually available. Turn them around and drive the grids of your modulator using your Bogen as a speech amp. I have a Bogen 60MX driving the grids of my 805s. ? Mod-U-Lator, Mike(y)/W3SLK ? ? ? From: [email protected] [mailto:[email protected]] On Behalf Of kc1at via groups.io ? Thats what I'm leaning towards now. Scrap the input with all those 12AU7s and do something else. Reverse engineering that circuit seems fruitless . Not sure it even worked when built. ? Took a look at those TOA amps. I had no idea there were so many of them. Found a Bogen amp in my junk box. also has a 4-8 and 70.7 output with a cheap 4 band equalizer. Gonna drag that out to see if it has any hope of working. ? Going into my iron now to see if I can support? a single 4-400. ? thanks everyone for the help ? don |
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I would be interested to know how you interface the TOA amp to the
modulator tubes in my case using a pair TZ40s?
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73 Mike VK2AMF ? At 02:18 AM 6/02/2025, you wrote: I would rip all the front-end tubes out and drive it with a 10W TOA amplifier. You can get these cheap on ebay and other websites.? $20 to $30 bucks. They have 4/8 and a 70v output with balanced and unbalanced and a Mic input. These work great to drive a pair of modulators.? They also have bass and treble.? I use several here for that purpose. |
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HaL Mandel