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 ?
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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?
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
Sent: Tuesday, February 04, 2025 6:35 AM
To: [email protected]
Subject: [ham-amplifiers] Dilemma ? 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.
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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 ?
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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
Sent: Tuesday, February 04, 2025 6:35 AM
To: [email protected]
Subject: [ham-amplifiers] Dilemma ? 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.
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Re: AL-82 Date of Manufacture
Matt,
?
Thanks for the reply.
?
73,
Garry
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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
|
Hey Chuck.? Have not had a QSO is a long time. Where are you hanging out these days on AM?
W7WRX
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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
Sent: Tuesday, February 04, 2025 6:35 AM
To: [email protected]
Subject: [ham-amplifiers] Dilemma
?
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.
|
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 ?
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Show quoted text
From: [email protected] [mailto:[email protected]] On Behalf Of kc1at via groups.io
Sent: Tuesday, February 04, 2025 6:35 AM
To: [email protected]
Subject: [ham-amplifiers] Dilemma ? 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.
|
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
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I would sell all your tubes and buy 1? ?8877.? Just my opinion.
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
|
I would sell all your tubes and buy 1? ?8877.? Just my opinion.
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
|
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 ? ? ?
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From: [email protected] [mailto:[email protected]] On Behalf Of kc1at via groups.io
Sent: Tuesday, February 4, 2025 6:35 AM
To: [email protected]
Subject: [ham-amplifiers] Dilemma ? 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.
|
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
|
Sideband Engineers SB-2LA
This one is from 1965:
A ham I know says his ant relay is stuck, its an open frame relay
he says. Probably no parts for this one around anymore?
--
Steve Hearns [ KA2PTE ]
Technotronic Dimensions, VT [USA]
WWW.TECHNOTRONIC-DIMENSIONS.COM
E-Mail: Steve@...
|
Update: ?Southeastern VHF Society 2025 Conference Announcement & Call For Papers
#2MAmplifier
The timeline for submission of papers and presentations has been extended to March 17th.
|
Re: Smoker contamination removal
Removed the tube sub-chassis, and have it soaking in the Fan-monia bucket....
its really got a lot of buildup as the blower was throwing it all right in there.
I got a new blower from ACOM recently, and I soaked down the rest of the chassis
frame, and cleaned it with the Fan-Monia....hard to tell there was any contamination
at all in there now.
--
Steve Hearns [ KA2PTE ]
Technotronic Dimensions, VT [USA]
Authorized ACOM Service center
WWW.TECHNOTRONIC-DIMENSIONS.COM
E-Mail: Steve@...
|
The 3-500zg tube with the graphite plate can handle 600ma ICAS ? The regular 3-500 rated 450ma CCS! ?With enough cooling (very important factor) you could run 2000 watts pep output SSB with a pair of tubes. ?Most vintage amps do not have the transformer capability of this anyhow except for the older Henry amps that can do this. ?
On Friday, January 31, 2025, 12:50 AM, Fran?ois via groups.io <18471@...> wrote: > Attached, please find a great book about tubed amplifiers. ? Hello ? Thank you for this communication. ? Even if it does not answer my question, this document is very interesting, both at the technological and implementation level. ? I reformulate my initial questions: ·???????? What is the maximum anode current (reasonable) for a 3-500Z tube ·???????? What maximum current can be used in a Drake L 7 to bake the tubes (not in RF operation), compared to the transformer capacity for example. ? I measured some characteristics of the HV transformer (measured in short circuit) ·???????? Transformation ratio o?? In CW: 2.95 o?? In SSB: 4.14 ·???????? Resistance brought back to the secondary o?? In CW: 13.4 ? o?? In SSB: 18.6 ? ? ? De la part de HaL Mandel via groups.io
贰苍惫辞测é?: jeudi 30 janvier 2025 21:30
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The original? C41 cap (47 pf) is failure prone.? ?Replace it with a 50 pf TX doorknob cap.? ?The original cap? was made from pc board.
C42? ( 307 pf)? is used to pad the TUNE cap on 160m only.? ?It's failure prone too.? ?Replace it with a 300 pf doorknob.
C39 and C40? will eventually fail.? ?Replace? with a pair of 1000 pf @ 5/7.5 kv doorknobs.? ?The original caps were discs types.?
|
Re: Commander HF-2500 Plate Choke
The 3 x section choke,? currently sold by ameritron,? is now screwed up.? Ameritron ran outa 28 ga wire...and started using 27 ga wire.? ?The pair of gaps is way less.? Steve at RF parts got a ton of the screwed up ones....and sent me one to test on my vna.? ?The screwed up version series resonates on 20m and 17m.? Scott got one of the screwed up versions and tossed it.?
The ONLY version of that choke that is wound correctly is sold by W8JI? at CTR engineering.?
I got 2 from RF parts years ago....and tested both of em on the VNA.? ?They resonate at aprx 12.5 mhz...and also 16.5 mhz.? Normal.
Interestingly enough, the 154 uh plate choke in all 4 of my L4B's? ?resonates at 12.5 mhz...and 16.5 mhz.? ? The drake choke is just one winding.?
Now how a good ameritron choke resonates on 30m band, on older alpha's is beyond me.? Close proximity to metal, and / or dielectrics will? shift the resonant freqs down.
The ameritron choke is 6" tall....and is too tall for the L4B.? Barely any clearance between top screw on choke...and top lid.?
|
> Attached, please find a great book about tubed amplifiers. ? Hello ? Thank you for this communication. ? Even if it does not answer my question, this document is very interesting, both at the technological and implementation level. ? I reformulate my initial questions: ·???????? What is the maximum anode current (reasonable) for a 3-500Z tube ·???????? What maximum current can be used in a Drake L 7 to bake the tubes (not in RF operation), compared to the transformer capacity for example. ? I measured some characteristics of the HV transformer (measured in short circuit) ·???????? Transformation ratio o?? In CW: 2.95 o?? In SSB: 4.14 ·???????? Resistance brought back to the secondary o?? In CW: 13.4 ? o?? In SSB: 18.6 ? ? ? De la part de HaL Mandel via groups.io
贰苍惫辞测é?: jeudi 30 janvier 2025 21:30
|
Re: Commander HF-2500 Plate Choke
Dear? Riki,
?
Tom, W8JI,
W8JI
W8JI
https://www.w8ji.com
?
is a coil-winder from Days Gone By.
?
Look up his website and see the variety of
RF Chokes he offers.
?
Hal Mandel
W4HBM
|
Dear Francois,
?
Attached, please find a great book about tubed amplifiers.
?
’73,
?
Hal Mandel
W4HBM
|
I am still studying a way to cook my 3-500Z which have not been hot for at least 15 years. The idea is to cook at high current with a low anode voltage, without HF. ? The maximum rating of the cathode current is not clear in the Eimac specifications. There are examples with a current of 0.4 A (for one tube). ·???????? Does this current (0.4 A) seem acceptable to you? ·???????? Can we go beyond that? This requires a grid voltage of around +30/+40V 100 mA. So 4 W and the tube is given for 20W ? I am considering using, temporarily, another transformer, with a lower secondary voltage, upstream of the doubler. ? Is this a bad idea?
|
HaL Mandel
Technotronic Dimensions
Robin Midgett