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Re: Ameritron AL-1500 Relay
开云体育Try w8JI, CTR Engineering, he may have one.73? Andy? K9ATX On 2/23/2025 8:28 PM, Riki, K7NJ via
groups.io wrote:
-- "Where the Old Soo crossed the New Soo" Duplainville, Wisconsin Broadcastify Train Scanner: Youtube Channel: |
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Ameritron AL-1500 Relay
The output relay in my Ameritron AL-1500 needs to be changed. I checked with MFJ since they are still selling some Ameritron replacement parts, but no luck.? From the user manual, this is "RLY1" and its Ameritron part number is 408-6139.
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This is a 3PDT, 10A, 12V DC through hole PCB mount relay. Two of the poles are used for RF switching and the third is used for another function. I've searched on Mouser, Digikey, Allied, Newark and E-bay websites without finding anything that might be a satisfactory replacement.
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Ideally, an original replacement part would be found. This would allay my concern about the contact materials which should be gold or gold plated for the two NC RF contacts to ensure good contact when receiving.?
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Suggestions would be appreciated.
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73 de Riki K7NJ?
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Re: Drake L-7
WRX, with 200w drive, how much grid and plate current was it running? Bob W4JFA? On Sat, Feb 15, 2025, 2:11 PM W7WRX via <clark=[email protected]> wrote:
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Re: Drake L-7
开云体育
Which models had 4kv on the plate?? A Triode is only going to give 10 to 12 DB of gain.??
Man, I have worked on and rebuilt pretty much all of these amps and even the later 3KA with its HD supply won't do 2kw.? It does not have 4KV on plate.? I was curious which ones did.? It's rated at 3k input and the efficiency is pretty poor.??
Henry used horrible small Fil chokes in series.? These things need to be tossed in the trash.? They get super-hot and after years of use the permeability changes.? they get harder and harder to drive.
Its so bad that the Tubes won't have the same fil voltage on them. Thats why these things always have one bright tube.? One of the tubes can be a half to a full volt off!?
The last one I rebuilt made 1800W out on low bands but needed a 200W radio to get there. It really works hard there.? ?I put a fil transformer in with a proper Fil choke.? Now each tube is spot on for voltage.? The amp runs so much better.? The blower is way
too small.? I put a Dayton ball bearing blower it. Half the noise and twice the air.?
C
From: [email protected] <[email protected]> on behalf of Louis Parascondola via groups.io <Gudguyham@...>
Sent: Friday, February 14, 2025 3:41 PM To: [email protected] <[email protected]> Subject: Re: [ham-amplifiers] Drake L-7 ?
It’s a well known fact that the Ameritron AL80b can obtain 1kw output ?pep?with a single 3-500. They only run 3000 volts anode voltage. ?The old Henry amps made prior to the power rule change were used in some Embassies. ?For that use they were running
the same amps sold to hams. ?The Henry amps had choke input filers and 4000 volts anode and the?plate voltage was rock steady. ?Easily capable of 2kw pep output. ?Naturally the ham manuals didn’t necessarily boast that sort of power and tune up instructions
were geared towards legal limits. ?Hence the CW/SSB change in voltage. ?Load to 1 kwdc input on CW Carrier) switch to SSB and talk and get 2kw pep input, but dare not let down in the SSB voltage!!! You’ll break the law. ?When the 1500 pep putput came in, away
went the cw/SSB switches, not need for them anymore!!
On Friday, February 14, 2025, 12:51 PM, W7WRX <clark@...> wrote:
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Re: Drake L-7
The Tokyo High power HL2K? with 3-500s was also such a amp. It had proper cooling(fully pressurised) On 240 VAC it could easily hit 2KW pep even though it was rated for 1.2KW PEP. Much like the TL922 which can? easily hit 1.5KW pep on 20 metres and below. The Tokyo high power HL2K was a popular RTTY? contest amp because it would not break down or melt parts and pins because of proper cooling. I think Amp Supply also had a heavy duty 3-500Z 3 or 4 holer, I cant remember.? |
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Re: Drake L-7
It’s a well known fact that the Ameritron AL80b can obtain 1kw output ?pep?with a single 3-500. They only run 3000 volts anode voltage. ?The old Henry amps made prior to the power rule change were used in some Embassies. ?For that use they were running the same amps sold to hams. ?The Henry amps had choke input filers and 4000 volts anode and the?plate voltage was rock steady. ?Easily capable of 2kw pep output. ?Naturally the ham manuals didn’t necessarily boast that sort of power and tune up instructions were geared towards legal limits. ?Hence the CW/SSB change in voltage. ?Load to 1 kwdc input on CW Carrier) switch to SSB and talk and get 2kw pep input, but dare not let down in the SSB voltage!!! You’ll break the law. ?When the 1500 pep putput came in, away went the cw/SSB switches, not need for them anymore!!
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On Friday, February 14, 2025, 12:51 PM, W7WRX <clark@...> wrote:
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Re: Drake L-7
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From: [email protected] <[email protected]> on behalf of Jim VE7RF via groups.io <jim.thom@...>
Sent: Friday, February 14, 2025 3:29 AM To: [email protected] <[email protected]> Subject: Re: [ham-amplifiers] Drake L-7 ?
Some versions of the older Henry amps were rated for 2 kw pep out on ssb.? But they also had improved cooling and also a bigger B+ supply.?
To getter older tubes, on the drake L7,? you can use the lower (1900 vdc) position, and temp shunt out any bias ( shunt out any series diodes used for bias)...and then apply a bit ( a few watts, 10-20 watts) of drive, and maladjust the tune control to put the tank circuit off resonance...such that both tubes show some colour.? |
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Re: Drake L-7
Some versions of the older Henry amps were rated for 2 kw pep out on ssb.? But they also had improved cooling and also a bigger B+ supply.? To getter older tubes, on the drake L7,? you can use the lower (1900 vdc) position, and temp shunt out any bias ( shunt out any series diodes used for bias)...and then apply a bit ( a few watts, 10-20 watts) of drive, and maladjust the tune control to put the tank circuit off resonance...such that both tubes show some colour.? |
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Re: Dilemma
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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Re: Dilemma
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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Re: Dilemma
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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Re: Dilemma
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
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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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Re: 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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Re: Dilemma
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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Re: Dilemma
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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Re: Dilemma
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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Re: Dilemma
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 |