Keyboard Shortcuts
Likes
- Ham-Amplifiers
- Messages
Search
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
开云体育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:
|
Re: Commander HF-2500 meter lamps and HV PS
开云体育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:
|
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
开云体育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:
|
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
开云体育? Where it gets complicated is in this case ? -- F1AMM Fran?ois ? De la part de Kim Elmore |
Re: SB-1000
开云体育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.
toggle quoted message
Show quoted text
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, |
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
开云体育See ? for the full treatise. 73, Kim N5OP On 4/17/2025 6:47 PM, Adrian Fewster
via groups.io wrote:
--
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:
--
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:
--
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:
--
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:
--
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
|