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Harbach Electronics And Homebrew HF Amps

 

Harbach Electronics has started their own FB group. "This is a place for people to post pictures of their Harbach kit installs, Homebrew ham pa projects and brainstorm ideas".



It's actually quite well done.? ?The kits need? a diagram, and some other minor tweaks in the documentation.


Re: Commander HF-2500 meter lamps and HV PS

 

That’s a SB-1000. Just showing the dirt on the strip that I pulled off the relay.?


Re: Commander HF-2500 meter lamps and HV PS

 

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Hmmm alright. That doesn't look like a Commander HF-2500 with 3CX800A7s. ?

On 20/04/2025 6:10 am, KG2RG via groups.io wrote:

Hmmm, the relay is right there??

I do want to clean the relay. I cut strips of paper, saturate them with DeoxIT, and clean the tint acts on the relays. They are almost always dirty.?


Re: Commander HF-2500 meter lamps and HV PS

 

Hmmm, the relay is right there??

I do want to clean the relay. I cut strips of paper, saturate them with DeoxIT, and clean the tint acts on the relays. They are almost always dirty.?


Re: Commander HF-2500 meter lamps and HV PS

 

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No. Just remove the rear panel screws and fold the panel down to get to the relay/s. There's also the relay on the control board.

Cheers, Alek.

On 19/04/2025 1:51 pm, KG2RG via groups.io wrote:

Well, my goal was to just have the meters red in standby and green when ?out of standby but the 1 set of the poles are bad on the 2PDT standby switch.?

I don’t want colors changing between TX and RX but that could potentially work but you would need to pull out the entire RF deck to access the relay. The other issue is the limited current on the 12V 1amp supply for the relay and meter lights.
?
Anyway, I may try to find a replacement switch that matches the one in there now.
?Thank you for your info, it’s definitely possible.
on my SB-220, I have one of the meters go dark when in standby. The standby on the SB-220 is a mod and it’s nice to have the indication of the am in standby or not from the lights in the meter. ?


Re: Commander HF-2500 meter lamps and HV PS

 

Well, my goal was to just have the meters red in standby and green when ?out of standby but the 1 set of the poles are bad on the 2PDT standby switch.?

I don’t want colors changing between TX and RX but that could potentially work but you would need to pull out the entire RF deck to access the relay. The other issue is the limited current on the 12V 1amp supply for the relay and meter lights.
?
Anyway, I may try to find a replacement switch that matches the one in there now.
?Thank you for your info, it’s definitely possible.
on my SB-220, I have one of the meters go dark when in standby. The standby on the SB-220 is a mod and it’s nice to have the indication of the am in standby or not from the lights in the meter. ?


Re: Commander HF-2500 meter lamps and HV PS

 

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The solution is simple if you want the colours to change between Tx and Rx. Install another small SPDT relay in parallel with the keying relay and wire each strip through the contacts.

73, Alek VK6APK.

On 19/04/2025 9:03 am, KG2RG via groups.io wrote:

So I installed 2 LED strips that draw 66mA each. I tried to utilize that standby DPDT but the one set of poles is shot. Anyway, I’m just running both strips, red and green. I may drop the voltage to the strips because they are so bright, but good to be out of the dark on those meters.?


Re: Commander HF-2500 meter lamps and HV PS

 

I guess the 15sec videos are not allowed.?
I’ll try to add a pic when I get home but it’s pretty cool.?


Re: Commander HF-2500 meter lamps and HV PS

 

So I installed 2 LED strips that draw 66mA each. I tried to utilize that standby DPDT but the one set of poles is shot. Anyway, I’m just running both strips, red and green. I may drop the voltage to the strips because they are so bright, but good to be out of the dark on those meters.?


Re: SB-1000

 

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?

Where it gets complicated is in this case

?

--

F1AMM

Fran?ois

?

De la part de Kim Elmore
贰苍惫辞测é?: vendredi 18 avril 2025 01:59


Re: SB-1000

 

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Thank you for sharing your attachment. I tried to find a link to this document online by searching in Google:

?

"the power consumed by the bias source"

?

The result is surprising and here are some of the product links

?

·????????

·????????

·????????

·????????

·????????

·???????? etc.

?

Happy reading!

--

F1AMM

Fran?ois


Re: SB-1000

 

FB ON YR HB AM XMTR!

DE ED, KI6DCB (Seventy-two years old and off-air until I build a new shack with acres of antennas (antennae? HI HI) ready to go. I'm going to be using Icom's excellent IC-275H, IC-375A, 475H, 575H, and 1275A on VHF and UHF, with an old Kenwood TS-940SAT and a homebrew, dual 4-1000A, Class A, push-pull amplifier. Going to TS-990A and SDR soon, all for HF.)?

TX 4 EMAIL QSO? K

On Thursday, April 17, 2025 at 06:12:44 PM PDT, KG2RG via groups.io <justinandyazny@...> wrote:


Eimac data sheet does show 890 watts out, but the plate voltage needs to be 3500 at full load. The AL-80 amps do not have this much plate voltage. Unless you’re a CBer on 11M. Hi hi
?
also, in Class C the driving power and peak grid-cathode voltage will be higher. ?my home brew AM transmitter runs a pair of 1625s modulated by a pair. The RF deck runs a pair of 1625s in class C but the modulator runs a pair of 1625s in class AB1 push pull.?

anyway, happy to see everyone interrested in this topic. Nice to see people engaged, even if some comments have the posters not exactly in the ball park. Very entertaining!?

?



Re: SB-1000

 

It's average Watts, not RMS Watts.

RMS Volts (0.707 peak) X RMS Current (0.707 peak) = Average Power

0.707 X 0.707 = 0.5

RMS Watts does not exist. There is peak power and average power but no RMS power.

Alek, VK6APK

On 18/04/2025 8:16 am, Adrian Fewster via groups.io wrote:
So it seems reference below that they consider watts as peak watts, and RMS watts as continuous power value equivalent,

which I always thought 'W' watts represented without need to be called RMS watts...


73


vk4tux

On 18/4/25 10:10, Adrian Fewster via groups.io wrote:

This one is interesting ;




73


vk4tux




Re: SB-1000

 

Eimac data sheet does show 890 watts out, but the plate voltage needs to be 3500 at full load. The AL-80 amps do not have this much plate voltage. Unless you’re a CBer on 11M. Hi hi
?
also, in Class C the driving power and peak grid-cathode voltage will be higher. ?my home brew AM transmitter runs a pair of 1625s modulated by a pair. The RF deck runs a pair of 1625s in class C but the modulator runs a pair of 1625s in class AB1 push pull.?

anyway, happy to see everyone interrested in this topic. Nice to see people engaged, even if some comments have the posters not exactly in the ball park. Very entertaining!?

?



Re: SB-1000

 

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See

?

for the full treatise.

73,

Kim N5OP

On 4/17/2025 6:47 PM, Adrian Fewster via groups.io wrote:

I agree with the later part of your response, but you sort of contradicted yourself with

""Peak" on a watt meter is the peak power, which is always part of a a running-RMS (like a running mean but RMS instead) power. "

but then you said ;

"There is no such thing as "RMS power"

I guess my point is getting back to basic AC, is looking over a 360 degree cycle? with peak, valley and then a rms value to equate it to a DC constant.

I agree that power that varies over time can have max and minimum value for the time mapped.

Do you agree with Kims comment re "There’s no such thing as “RMS power”; peak power come from peak RMS values."

In the audio world ;

Root mean square or simply RMS watts refers to?continuous power handling of a speaker or a subwoofer or how much continuous power an amplifier can output. RMS values are usually lower than peak watts ratings, but they represent what a unit is truly capable of handling.


73


vk4tux



peak power come from peak RMS values

On 18/4/25 09:32, Kim Elmore via groups.io wrote:

That's simply incorrect. Our voice "peaks" are very long, compared to the RF frequency, they they have do indeed have a running RMS value. "Peak" on a watt meter is the peak power, which is always part of a a running-RMS (like a running mean but RMS instead) power.?

Your house current id 60 Hz and has a peak voltage of about 169 V. Is your light blulb or power input to you amp rated based on 120 VAC or 169 V peak AC? Yes, wire insulation must be rated for the peak voltage it is to with stand, but it's current carrying capacity is rated in the RMS current. There is no such thing as "RMS power": it's simply power, computed based on the RMS voltage, current, or the RMS voltage squared over the impedance, or the RMS current squared milipaited by the impedance.

73,

Kim N5OP

--

Kim Elmore, Ph.D. (Adj. Assoc. Prof., OU School of Meteorology, CCM, PP SEL/MEL/Glider, UAS, N5OP, 2nd Class Radiotelegraph, GROL)

“Listen, it's too big a world to be in competition with everybody else. The only guy I have to get better than is who I am right now.” – Col. Sherman T. Potter, 4077 M.A.S.H.


Re: SB-1000

 

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Power is RMS. Power can vary, but it's always RMS. The idea is that for sine wave AC, RMS voltage and current will dissipate the same power as the DC values for both. My digital vector RF watt meter does not magically switch to computing power from the peak RF voltage when I switch it to peak. To do would be nonsensical.When I select "average" it yields the average over some integration period; it doesn't switch to RMS.?

73,

Kim N5OP

On 4/17/2025 6:47 PM, Adrian Fewster via groups.io wrote:

I agree with the later part of your response, but you sort of contradicted yourself with

""Peak" on a watt meter is the peak power, which is always part of a a running-RMS (like a running mean but RMS instead) power. "

but then you said ;

"There is no such thing as "RMS power"

I guess my point is getting back to basic AC, is looking over a 360 degree cycle? with peak, valley and then a rms value to equate it to a DC constant.

I agree that power that varies over time can have max and minimum value for the time mapped.

Do you agree with Kims comment re "There’s no such thing as “RMS power”; peak power come from peak RMS values."

In the audio world ;

Root mean square or simply RMS watts refers to?continuous power handling of a speaker or a subwoofer or how much continuous power an amplifier can output. RMS values are usually lower than peak watts ratings, but they represent what a unit is truly capable of handling.


73


vk4tux



peak power come from peak RMS values

On 18/4/25 09:32, Kim Elmore via groups.io wrote:

That's simply incorrect. Our voice "peaks" are very long, compared to the RF frequency, they they have do indeed have a running RMS value. "Peak" on a watt meter is the peak power, which is always part of a a running-RMS (like a running mean but RMS instead) power.?

Your house current id 60 Hz and has a peak voltage of about 169 V. Is your light blulb or power input to you amp rated based on 120 VAC or 169 V peak AC? Yes, wire insulation must be rated for the peak voltage it is to with stand, but it's current carrying capacity is rated in the RMS current. There is no such thing as "RMS power": it's simply power, computed based on the RMS voltage, current, or the RMS voltage squared over the impedance, or the RMS current squared milipaited by the impedance.

73,

Kim N5OP

--

Kim Elmore, Ph.D. (Adj. Assoc. Prof., OU School of Meteorology, CCM, PP SEL/MEL/Glider, UAS, N5OP, 2nd Class Radiotelegraph, GROL)

“Listen, it's too big a world to be in competition with everybody else. The only guy I have to get better than is who I am right now.” – Col. Sherman T. Potter, 4077 M.A.S.H.


Re: SB-1000

 

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Keep in mind that a single sine wave cycle has an RMS value that is peak/1.414.

73,

Kim Elmore

On 4/17/2025 6:32 PM, Kim Elmore wrote:

That's simply incorrect. Our voice "peaks" are very long, compared to the RF frequency, they they have do indeed have a running RMS value. "Peak" on a watt meter is the peak power, which is always part of a a running-RMS (like a running mean but RMS instead) power.?

Your house current id 60 Hz and has a peak voltage of about 169 V. Is your light blulb or power input to you amp rated based on 120 VAC or 169 V peak AC? Yes, wire insulation must be rated for the peak voltage it is to with stand, but it's current carrying capacity is rated in the RMS current. There is no such thing as "RMS power": it's simply power, computed based on the RMS voltage, current, or the RMS voltage squared over the impedance, or the RMS current squared milipaited by the impedance.

73,

Kim N5OP

On 4/17/2025 6:04 PM, Adrian Fewster via groups.io wrote:

Well our RF wattmeter usually has peak and avg selections ?? RMS is converting the AC to a DC value that is constant to

determine the constant heat W emitted. At a peak time snapshot , peak power and peak voltage are true for that moment.

Think of it like shoveling coal into a boiler. The heat produced is determined by the average coal added? time rather than peak

coal added in a moment.

So 'peak RMS values ' does not make sense, as once converted to rms there are no peaks nor valleys for the math purpose.


73


vk4tux

On 18/4/25 05:33, Kim Elmore via groups.io wrote:
I can’t help but chime in: RMS is the only value that makes sense. Outlet voltage in your house is 120 V RMS. There’s no such thing as “RMS power”; peak power come from peak RMS values.?

Kim
N5OP


"People that make music together cannot be enemies, at least as long as the music lasts."?-- Paul Hindemith

On Apr 17, 2025, at 11:55, KG2RG via groups.io <justinandyazny@...> wrote:

?
Duty cycle is considered. These are peak voltage obtained by 100% duty cycle continues wave.
?
the Eimac formula for calculating grid dissipation is based on peak.?
Pg = vga X Ig
?
anyway, anything I state is like I said, this is what I know, how I calculate it. I’m not an engineer, just an amateur. There are plenty of engineers floating around here and if I’m incorrect, I would love to be corrected as that would benefit myself and I’m always open to learning more. Any day I can learn is a day of victory.
?
PS, this stuff is the fun part of the hobby!?
?
73!!


--

Kim Elmore, Ph.D. (Adj. Assoc. Prof., OU School of Meteorology, CCM, PP SEL/MEL/Glider, UAS, N5OP, 2nd Class Radiotelegraph, GROL)

“Listen, it's too big a world to be in competition with everybody else. The only guy I have to get better than is who I am right now.” – Col. Sherman T. Potter, 4077 M.A.S.H.

--

Kim Elmore, Ph.D. (Adj. Assoc. Prof., OU School of Meteorology, CCM, PP SEL/MEL/Glider, UAS, N5OP, 2nd Class Radiotelegraph, GROL)

“Listen, it's too big a world to be in competition with everybody else. The only guy I have to get better than is who I am right now.” – Col. Sherman T. Potter, 4077 M.A.S.H.


Re: SB-1000

 

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I believe those were peak *input* power levels. This is what upset AM fans so much when it was changed to 1500 W peak output, because they could get more than 1500 W peak? power with 2000 W peak input running Class C plate modulation.

73,

Kim N5OP

On 4/17/2025 5:46 PM, Dave w6de wrote:

Grids don’t have enough thermal mass for protection like a plate has.? Exceeding peak values are enough to blow out a grid.

?

Many moons ago, I had a Henry 3-KA it had a pair of Eimac 3-500Zs had sheet metal plates and ~ 3500 Volts on the plates.? It was a beast.? It was a mess when I bought it.? I had to rebuilt the plate circuit wiring and replace the noisy plate circuit fan.? I replaced the fan with a more powerful Dayton squirrel cage blower.

This was in the days when the US FCC power limits were 2K peak output.? The FCC intended that 2K peak to be for SSB. ?But the rule was written 2KW peak.? 2KW peak for SSB is also 2 KW peak for CW. ?At that power level the plates were a nice dull red—just like the spec sheets says.? And a Bird Wattmeter indicated 2 KW output—probably exceeded the 500 Watt per tube dissipation but the greater air volume helped mitigate that some.? Worked out well for a bunch of CQ World-Wide Contests.

?

73,

Dave, w6de

?

From: [email protected] <[email protected]> On Behalf Of Kim Elmore via groups.io
Sent: 17 April, 2025 19:33
To: [email protected]
Subject: Re: [ham-amplifiers] SB-1000

?

I can’t help but chime in: RMS is the only value that makes sense. Outlet voltage in your house is 120 V RMS. There’s no such thing as “RMS power”; peak power come from peak RMS values.?

?

Kim

N5OP

?

?

"People that make music together cannot be enemies, at least as long as the music lasts."?-- Paul Hindemith



On Apr 17, 2025, at 11:55, KG2RG via groups.io <justinandyazny@...> wrote:

?

Duty cycle is considered. These are peak voltage obtained by 100% duty cycle continues wave.

?

the Eimac formula for calculating grid dissipation is based on peak.?
Pg = vga X Ig

?

anyway, anything I state is like I said, this is what I know, how I calculate it. I’m not an engineer, just an amateur. There are plenty of engineers floating around here and if I’m incorrect, I would love to be corrected as that would benefit myself and I’m always open to learning more. Any day I can learn is a day of victory.

?

PS, this stuff is the fun part of the hobby!?

?

73!!

?

--

Kim Elmore, Ph.D. (Adj. Assoc. Prof., OU School of Meteorology, CCM, PP SEL/MEL/Glider, UAS, N5OP, 2nd Class Radiotelegraph, GROL)

“Listen, it's too big a world to be in competition with everybody else. The only guy I have to get better than is who I am right now.” – Col. Sherman T. Potter, 4077 M.A.S.H.


Re: SB-1000

 

开云体育

That's simply incorrect. Our voice "peaks" are very long, compared to the RF frequency, they they have do indeed have a running RMS value. "Peak" on a watt meter is the peak power, which is always part of a a running-RMS (like a running mean but RMS instead) power.?

Your house current id 60 Hz and has a peak voltage of about 169 V. Is your light blulb or power input to you amp rated based on 120 VAC or 169 V peak AC? Yes, wire insulation must be rated for the peak voltage it is to with stand, but it's current carrying capacity is rated in the RMS current. There is no such thing as "RMS power": it's simply power, computed based on the RMS voltage, current, or the RMS voltage squared over the impedance, or the RMS current squared milipaited by the impedance.

73,

Kim N5OP

On 4/17/2025 6:04 PM, Adrian Fewster via groups.io wrote:

Well our RF wattmeter usually has peak and avg selections ?? RMS is converting the AC to a DC value that is constant to

determine the constant heat W emitted. At a peak time snapshot , peak power and peak voltage are true for that moment.

Think of it like shoveling coal into a boiler. The heat produced is determined by the average coal added? time rather than peak

coal added in a moment.

So 'peak RMS values ' does not make sense, as once converted to rms there are no peaks nor valleys for the math purpose.


73


vk4tux

On 18/4/25 05:33, Kim Elmore via groups.io wrote:
I can’t help but chime in: RMS is the only value that makes sense. Outlet voltage in your house is 120 V RMS. There’s no such thing as “RMS power”; peak power come from peak RMS values.?

Kim
N5OP


"People that make music together cannot be enemies, at least as long as the music lasts."?-- Paul Hindemith

On Apr 17, 2025, at 11:55, KG2RG via groups.io <justinandyazny@...> wrote:

?
Duty cycle is considered. These are peak voltage obtained by 100% duty cycle continues wave.
?
the Eimac formula for calculating grid dissipation is based on peak.?
Pg = vga X Ig
?
anyway, anything I state is like I said, this is what I know, how I calculate it. I’m not an engineer, just an amateur. There are plenty of engineers floating around here and if I’m incorrect, I would love to be corrected as that would benefit myself and I’m always open to learning more. Any day I can learn is a day of victory.
?
PS, this stuff is the fun part of the hobby!?
?
73!!


--

Kim Elmore, Ph.D. (Adj. Assoc. Prof., OU School of Meteorology, CCM, PP SEL/MEL/Glider, UAS, N5OP, 2nd Class Radiotelegraph, GROL)

“Listen, it's too big a world to be in competition with everybody else. The only guy I have to get better than is who I am right now.” – Col. Sherman T. Potter, 4077 M.A.S.H.


Re: SB-1000

 

开云体育

Grids don’t have enough thermal mass for protection like a plate has.? Exceeding peak values are enough to blow out a grid.

?

Many moons ago, I had a Henry 3-KA it had a pair of Eimac 3-500Zs had sheet metal plates and ~ 3500 Volts on the plates.? It was a beast.? It was a mess when I bought it.? I had to rebuilt the plate circuit wiring and replace the noisy plate circuit fan.? I replaced the fan with a more powerful Dayton squirrel cage blower.

This was in the days when the US FCC power limits were 2K peak output.? The FCC intended that 2K peak to be for SSB. ?But the rule was written 2KW peak.? 2KW peak for SSB is also 2 KW peak for CW. ?At that power level the plates were a nice dull red—just like the spec sheets says.? And a Bird Wattmeter indicated 2 KW output—probably exceeded the 500 Watt per tube dissipation but the greater air volume helped mitigate that some.? Worked out well for a bunch of CQ World-Wide Contests.

?

73,

Dave, w6de

?

From: [email protected] <[email protected]> On Behalf Of Kim Elmore via groups.io
Sent: 17 April, 2025 19:33
To: [email protected]
Subject: Re: [ham-amplifiers] SB-1000

?

I can’t help but chime in: RMS is the only value that makes sense. Outlet voltage in your house is 120 V RMS. There’s no such thing as “RMS power”; peak power come from peak RMS values.?

?

Kim

N5OP

?

?

"People that make music together cannot be enemies, at least as long as the music lasts."?-- Paul Hindemith



On Apr 17, 2025, at 11:55, KG2RG via groups.io <justinandyazny@...> wrote:

?

Duty cycle is considered. These are peak voltage obtained by 100% duty cycle continues wave.

?

the Eimac formula for calculating grid dissipation is based on peak.?
Pg = vga X Ig

?

anyway, anything I state is like I said, this is what I know, how I calculate it. I’m not an engineer, just an amateur. There are plenty of engineers floating around here and if I’m incorrect, I would love to be corrected as that would benefit myself and I’m always open to learning more. Any day I can learn is a day of victory.

?

PS, this stuff is the fun part of the hobby!?

?

73!!

?