Re: [Elecraft] KPA-1500 Fan Noise - measured (sort of)
Bob please give us the model number of your acoustic level meter, Thanks. Mel, K6KBE From: "Stefan von Baltz, DL1IAO" To: "elecraft@mailman.qth.net" Sent: Monday, June 4, 2018 1:44 AM Subject: Re: [Elecraft] KPA-1500 Fan Noise - measured (sort of) Hello Bob, Thanks for the measurements! Was this with the Alpha’s auxiliary fan on or off? You will find this fan and its belonging switch on the amplifiers back on the right side where the power supply transformer sits. 73, Stefan DL1IAO, SA3CWW/SM9A -- Stefan v. Baltz dl1...@contesting.com http://www.dl1iao.com > Am 03.06.2018 um 20:33 schrieb Bob Rennard via Elecraft > : > > My measurements were taken with a microphone about 2 feet from the front > panels of the components. I wondered if W2PA’s alpha 89 was as quiet as he > reported, so I thought I’d report on what I found - > > > > Ham shack in a finished (insulated drywall) room in a metal shed with > equipment and HVAC off - 24 dBa > > Above with Mitsubishi HVAC on - 29 dBa > > HVAC was then turned off for the remainder of these measurements > > KPA1500 PS fans on, RF deck fans off (step 0) - 36 dBa > > KPA1500 PS fans on, RF deck fans at step 1 - 40 dBa > > KPA1500 PS fans on, RF deck fans at step 2 - 44 dBa > > KPA1500 PS fans on, RF deck fans at step 3 - 50 dBa > > KPA1500 PS fans on, RF deck fans at step 4 - 57 dBa > > KPA1500 PS fans on, RF deck fans at step 5 - 59 dBa > > > alpha 87a (everything else off) - 50 dBa - the fans run at a fixed speed when > mains power is applied > > > My experience for S CW during WPX is that the KPA1500 PA temp rose to about > 64C so that the deck fans were at Step 2. During a recent RTTY contest, the > deck rose above 70C and the fans were running at Step 3 pushing a lot of warm > air out of the vent holes above the heat sink. > > > 73 & YMMV, > > > Bob Rennard = N7WY > __ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:Elecraft@mailman.qth.net > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to dl1...@contesting.com __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to farrerfo...@yahoo.com __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] KPA-1500 Fan Noise - measured (sort of)
FWIW - My test using the Alpha 89, was with only the built-in fan on, not the add-on one in back (which I've never really had to use). 73, Chris, W2PA On 6/4/2018 4:43 AM, Stefan von Baltz, DL1IAO wrote: Hello Bob, Thanks for the measurements! Was this with the Alpha’s auxiliary fan on or off? You will find this fan and its belonging switch on the amplifiers back on the right side where the power supply transformer sits. 73, Stefan DL1IAO, SA3CWW/SM9A -- Stefan v. Baltz dl1...@contesting.com http://www.dl1iao.com Am 03.06.2018 um 20:33 schrieb Bob Rennard via Elecraft : My measurements were taken with a microphone about 2 feet from the front panels of the components. I wondered if W2PA’s alpha 89 was as quiet as he reported, so I thought I’d report on what I found - Ham shack in a finished (insulated drywall) room in a metal shed with equipment and HVAC off - 24 dBa Above with Mitsubishi HVAC on - 29 dBa HVAC was then turned off for the remainder of these measurements KPA1500 PS fans on, RF deck fans off (step 0) - 36 dBa KPA1500 PS fans on, RF deck fans at step 1 - 40 dBa KPA1500 PS fans on, RF deck fans at step 2 - 44 dBa KPA1500 PS fans on, RF deck fans at step 3 - 50 dBa KPA1500 PS fans on, RF deck fans at step 4 - 57 dBa KPA1500 PS fans on, RF deck fans at step 5 - 59 dBa alpha 87a (everything else off) - 50 dBa - the fans run at a fixed speed when mains power is applied My experience for S CW during WPX is that the KPA1500 PA temp rose to about 64C so that the deck fans were at Step 2. During a recent RTTY contest, the deck rose above 70C and the fans were running at Step 3 pushing a lot of warm air out of the vent holes above the heat sink. 73 & YMMV, Bob Rennard = N7WY __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to dl1...@contesting.com __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to w...@arrl.net __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] KPA-1500 Fan Noise - measured (sort of)
Hello Bob, Thanks for the measurements! Was this with the Alpha’s auxiliary fan on or off? You will find this fan and its belonging switch on the amplifiers back on the right side where the power supply transformer sits. 73, Stefan DL1IAO, SA3CWW/SM9A -- Stefan v. Baltz dl1...@contesting.com http://www.dl1iao.com > Am 03.06.2018 um 20:33 schrieb Bob Rennard via Elecraft > : > > My measurements were taken with a microphone about 2 feet from the front > panels of the components. I wondered if W2PA’s alpha 89 was as quiet as he > reported, so I thought I’d report on what I found - > > > > Ham shack in a finished (insulated drywall) room in a metal shed with > equipment and HVAC off - 24 dBa > > Above with Mitsubishi HVAC on - 29 dBa > > HVAC was then turned off for the remainder of these measurements > > KPA1500 PS fans on, RF deck fans off (step 0) - 36 dBa > > KPA1500 PS fans on, RF deck fans at step 1 - 40 dBa > > KPA1500 PS fans on, RF deck fans at step 2 - 44 dBa > > KPA1500 PS fans on, RF deck fans at step 3 - 50 dBa > > KPA1500 PS fans on, RF deck fans at step 4 - 57 dBa > > KPA1500 PS fans on, RF deck fans at step 5 - 59 dBa > > > alpha 87a (everything else off) - 50 dBa - the fans run at a fixed speed when > mains power is applied > > > My experience for S CW during WPX is that the KPA1500 PA temp rose to about > 64C so that the deck fans were at Step 2. During a recent RTTY contest, the > deck rose above 70C and the fans were running at Step 3 pushing a lot of warm > air out of the vent holes above the heat sink. > > > 73 & YMMV, > > > Bob Rennard = N7WY > __ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:Elecraft@mailman.qth.net > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to dl1...@contesting.com __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] KPA-1500 Fan Noise
Eric, based on the comments about fan speed, I was confident you and Wayne and team would address the issue with a good solution. I have one on order and scheduled to be received in July. 72 & 73, Bill K9YEQ FT'er for K2, KX1, KX3, KXPA100, KAT500, W2, etc. -Original Message- From: elecraft-boun...@mailman.qth.net On Behalf Of Eric Swartz - WA6HHQ, Elecraft Sent: Saturday, June 2, 2018 11:14 PM To: Les Peters Cc: elecraft@mailman.qth.net; elecraft-requ...@mailman.qth.net Subject: Re: [Elecraft] KPA-1500 Fan Noise One quick note: We have shifted up the fan turn on temperatures by about 7 degrees for Fan speed 2 and above in our next KPA1500 s/w release and on newly shipping amps. The release should be available in the next week or two. As noted by others, setting the minimum RF deck fan speed to 1 (or 2 if desired) also further delays going to higher fan speeds in TX. Also, since the RF deck is instant on, its OK to turn it off from the front panel when you are mostly listening and tuning the band. (The amp can also be set to power up in operate mode in its menu..) There are no limitations to turning it on and off frequently. (Of course we recommend letting it cool first before turning it off temporarily when running higher duty TX cycles.) 73, Eric elecraft.com _..._ __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to k9...@live.com __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] KPA-1500 Fan Noise - measured (sort of)
My measurements were taken with a microphone about 2 feet from the front panels of the components. I wondered if W2PA’s alpha 89 was as quiet as he reported, so I thought I’d report on what I found - Ham shack in a finished (insulated drywall) room in a metal shed with equipment and HVAC off - 24 dBa Above with Mitsubishi HVAC on - 29 dBa HVAC was then turned off for the remainder of these measurements KPA1500 PS fans on, RF deck fans off (step 0) - 36 dBa KPA1500 PS fans on, RF deck fans at step 1 - 40 dBa KPA1500 PS fans on, RF deck fans at step 2 - 44 dBa KPA1500 PS fans on, RF deck fans at step 3 - 50 dBa KPA1500 PS fans on, RF deck fans at step 4 - 57 dBa KPA1500 PS fans on, RF deck fans at step 5 - 59 dBa alpha 87a (everything else off) - 50 dBa - the fans run at a fixed speed when mains power is applied My experience for S CW during WPX is that the KPA1500 PA temp rose to about 64C so that the deck fans were at Step 2. During a recent RTTY contest, the deck rose above 70C and the fans were running at Step 3 pushing a lot of warm air out of the vent holes above the heat sink. 73 & YMMV, Bob Rennard = N7WY __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] KPA-1500 Fan Noise
At 09:14 PM 6/2/2018, Eric Swartz - WA6HHQ, Elecraft wrote: There are no limitations to turning it on and off frequently. (Of course we recommend letting it cool first before turning it off temporarily when running higher duty TX cycles.) I would have thought the software would have kept the fans running even if you tried turn the amp off, until it had cooled down sufficiently. That's certainly the way my ACOM 2000 works and many other amps. - Paul __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] KPA-1500 Fan Noise
One quick note: We have shifted up the fan turn on temperatures by about 7 degrees for Fan speed 2 and above in our next KPA1500 s/w release and on newly shipping amps. The release should be available in the next week or two. As noted by others, setting the minimum RF deck fan speed to 1 (or 2 if desired) also further delays going to higher fan speeds in TX. Also, since the RF deck is instant on, its OK to turn it off from the front panel when you are mostly listening and tuning the band. (The amp can also be set to power up in operate mode in its menu..) There are no limitations to turning it on and off frequently. (Of course we recommend letting it cool first before turning it off temporarily when running higher duty TX cycles.) 73, Eric elecraft.com _..._ __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] KPA-1500 Fan Noise - measured (sort of)
Those numbers are pretty impressive for quiet.
Certainly quieter than a quiet dishwasher unless you really pushing it.
Mike va3mw
On Sat, Jun 2, 2018 at 11:09 PM, Bob McGraw K4TAX
wrote:
> Using a Sound Level Meter with A weighted scale, measure the noise at 1
> meter in at least 4 different directions. Preferably done in a "free
> field" such that any acoustic reflections are at least 6 meters distant.
> I know it is difficult to make measurement outside on a piece of equipment
> such as this. But with these measurements one will have some quantitative
> data to evaluate. {One side may be noticeably quieter. Thus turning the
> amp 90º could make a difference.
>
> Also, an audio spectrum analysis of the noise would be nice. There may be
> certain frequencies related to blade tip speed, or bearing chatter which
> can be addressed.
>
> I know Jim, K9YC will have extensive knowledge about this method of
> evaluating "noise" and can offer some solid advice.
>
> 73
>
> Bob, K4TAX
>
>
> On 6/2/2018 6:12 PM, Chris Codella, W2PA wrote:
>
>> In an attempt to quantify this, I installed OSHA's free NIOSH app, which
>> measures noise, onto my iPhone 7 and tried it out. It's not a measurement
>> instrument, mind you, so the absolute numbers are highly questionable. But
>> the relative numbers are interesting. I held the phone at eye level
>> between me and my computer monitor, about 2 feet from the amplifiers. Here
>> are the results:
>>
>> dB measured with NIOSH app, rounded to two significant digits:
>>
>> 46 - for comparison - an Alpha 89 running as normal
>> 48 - KPA1500 at fan level 0 (i.e. PS fans only)
>> 51 - fan level 1 (i.e. center fan plus PS fans)
>> 57 - fan level 2 (all fans on)
>> 64 - fan level 3 (all fans on)
>> 67 - fan level 4 (all fans on)
>> 76 - fan level 5 (all fans on)
>>
>> Similar to other comments I've read, I find up through level 2 to be
>> okay. At 3 and above I need headphones or, better still, noise cancelling
>> ones. My experience thus far is that on SSB in normal conversation at
>> 1500W it stays at level 0 with an occasional excursion into level 1 if I'm
>> long winded. In the CW WPX test last weekend, strictly in S mode, it
>> stayed at level 0. Experiments with CQing and on FT-8 are yet to come and
>> I'm sure will require higher speeds.
>>
>> 73,
>> Chris, W2PA
>> __
>> Elecraft mailing list
>> Home: http://mailman.qth.net/mailman/listinfo/elecraft
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>> This list hosted by: http://www.qsl.net
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>>
>>
>
> __
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Re: [Elecraft] KPA-1500 Fan Noise - measured (sort of)
Using a Sound Level Meter with A weighted scale, measure the noise at 1
meter in at least 4 different directions. Preferably done in a "free
field" such that any acoustic reflections are at least 6 meters
distant. I know it is difficult to make measurement outside on a
piece of equipment such as this. But with these measurements one will
have some quantitative data to evaluate. {One side may be noticeably
quieter. Thus turning the amp 90º could make a difference.
Also, an audio spectrum analysis of the noise would be nice. There may
be certain frequencies related to blade tip speed, or bearing chatter
which can be addressed.
I know Jim, K9YC will have extensive knowledge about this method of
evaluating "noise" and can offer some solid advice.
73
Bob, K4TAX
On 6/2/2018 6:12 PM, Chris Codella, W2PA wrote:
In an attempt to quantify this, I installed OSHA's free NIOSH app,
which measures noise, onto my iPhone 7 and tried it out. It's not a
measurement instrument, mind you, so the absolute numbers are highly
questionable. But the relative numbers are interesting. I held the
phone at eye level between me and my computer monitor, about 2 feet
from the amplifiers. Here are the results:
dB measured with NIOSH app, rounded to two significant digits:
46 - for comparison - an Alpha 89 running as normal
48 - KPA1500 at fan level 0 (i.e. PS fans only)
51 - fan level 1 (i.e. center fan plus PS fans)
57 - fan level 2 (all fans on)
64 - fan level 3 (all fans on)
67 - fan level 4 (all fans on)
76 - fan level 5 (all fans on)
Similar to other comments I've read, I find up through level 2 to be
okay. At 3 and above I need headphones or, better still, noise
cancelling ones. My experience thus far is that on SSB in normal
conversation at 1500W it stays at level 0 with an occasional excursion
into level 1 if I'm long winded. In the CW WPX test last weekend,
strictly in S mode, it stayed at level 0. Experiments with CQing and
on FT-8 are yet to come and I'm sure will require higher speeds.
73,
Chris, W2PA
__
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Re: [Elecraft] KPA-1500 Fan Noise - measured (sort of)
Thanks Chris, I do not think I will buy the current configuration of the KPA-1500 fans. I was seriously doing so.. I would still like to know the model number of the fans. Mel, K6KBE From: "Chris Codella, W2PA" To: elecraft@mailman.qth.net Sent: Saturday, June 2, 2018 4:14 PM Subject: [Elecraft] KPA-1500 Fan Noise - measured (sort of) In an attempt to quantify this, I installed OSHA's free NIOSH app, which measures noise, onto my iPhone 7 and tried it out. It's not a measurement instrument, mind you, so the absolute numbers are highly questionable. But the relative numbers are interesting. I held the phone at eye level between me and my computer monitor, about 2 feet from the amplifiers. Here are the results: dB measured with NIOSH app, rounded to two significant digits: 46 - for comparison - an Alpha 89 running as normal 48 - KPA1500 at fan level 0 (i.e. PS fans only) 51 - fan level 1 (i.e. center fan plus PS fans) 57 - fan level 2 (all fans on) 64 - fan level 3 (all fans on) 67 - fan level 4 (all fans on) 76 - fan level 5 (all fans on) Similar to other comments I've read, I find up through level 2 to be okay. At 3 and above I need headphones or, better still, noise cancelling ones. My experience thus far is that on SSB in normal conversation at 1500W it stays at level 0 with an occasional excursion into level 1 if I'm long winded. In the CW WPX test last weekend, strictly in S mode, it stayed at level 0. Experiments with CQing and on FT-8 are yet to come and I'm sure will require higher speeds. 73, Chris, W2PA __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to farrerfo...@yahoo.com __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] KPA-1500 Fan Noise
It is NOT JUST a matter of of getting an HD15 M-->F extension cable (which can be had in lengths up to 100 feet. A VGA signal is analog and can be extended to up to 100 feet TOTAL according to the spec, all things being optimum. But one MUST look at the signals being sent between the KPA-1500 power supply and RF deck... Are they analog, digital, a mix? What are the timing spec requirements? Voltage levels? State difference, et al... Are there capacitance limitations, et al. 73, __ Clay Autery, KY5G (318) 518-1389 On 06/02/18 12:56, Don Wilhelm wrote: Les, A VGA extension will NOT do the job. Get a cable with all 15 pins connected straight through. 73, Don W3FPR On 6/2/2018 12:07 PM, Les Peters wrote: Jim I agree with your personal observations. I run some high duty cycle modes so I notice the fans kicking into speed 3 a lot when the PA temp gets to 68-70 degrees. That setting does a good job of reducing the temp and keeping it from climbing past 73 degrees. I've changed my min fan speed threshold from 0 to 1 to also help. As you have pointed out 1 is barely perceptible and this helps to reduce the amount of time that fan speeds are on 2+. I'd like to have more separation between the K3S and the KPA1500 RF deck to further distance any noise but the KPAK3AUX cable is only about five feet long, it would be great if that were more like ten feet. Since the cable pin out is straight thru I would imagine a DB15 VGA M-F extension cable would suffice? That would put the potential fan noise even further away but have the RF deck still plenty close enough to view. Les, N1SV #113 Date: Fri, 1 Jun 2018 23:07:20 -0400 From: "James F. Boehner MD" To: "'Elecraft Reflector'" Subject: [Elecraft] KPA-1500 Fan Noise Message-ID: <002901d3fa1e$d39e0db0$7ada2910$@yahoo.com mailto:002901d3fa1e$d39e0db0$7ada2910$@yahoo.com > Content-Type: text/plain; charset="utf-8" Just thought I would add a few thoughts as far as the fan noise. I'm not certain a YouTube piece would help, but perhaps personal observations might. First, via the menu, you can select the minimum fan speed, 0-5. Of course, the fan speed will go up with the Amp temperature. These are my personal observations: 0-Nothing 1-Barely perceptible 2-Acceptable fan noise, even for SSB operating. Low pitched whine 3-The noise and the pitch of the whine is past the acceptable point. Even a very directional mic will probably pick up the noise. This is where Noise Cancelling headphones would start to help. 4-Louder and higher pitched whine 5-Very loud and higher pitched whine So, the fan noise becomes particularly bothersome on level 3 and above. If you are doing CW and/or Digital, the noise will only be a factor with the operator. On SSB, the noise will probably be noticeable on the air. However, the SSB duty cycle may not require higher fan speeds. Those who have been active in contests will probably know that answer. Rich, if fan noise is going to be that strong a factor, perhaps you should be looking at tube amps instead. Personally, if I found the KPA-1500 fan noise excessive in the future, I would plan on moving it off my desk or remoting it rather than replacing it. It's integration with the K3 would be very hard to give up. ?73 de JIM N2ZZ #106 ** __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to donw...@embarqmail.com __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to k...@montac.com __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] KPA-1500 Fan Noise with added VGA comments
Not from Elecraft but... Yes the caution is warranted for "VGA" cables. They are not always pin for pin and can do two things wrong. One is that not all pins are wired and the other is worse as they sometimes tie the shields together shorting out needed pins. There are multiple versions of VGA cables. My source for the correct cables is L-Com here: http://www.l-com.com/d-sub-high-density-d-sub-cable-assemblies I've had good luck with products from them being reasonably priced and good quality. I'd just get the length I'd need rather than an extension. An extension adds another failure point as with all cabling jobs. 73, Bob K2TK ex KN2TKR (1956) & K2TKR On 6/2/2018 1:42 PM, James F. Boehner MD via Elecraft wrote: I would ask someone from Elecraft to respond to the VGA extension cable question. It seems everywhere I read within Elecraft Documentation is that standard VGA cables should NOT be used. In regards to extensions, I do not know if they all work pin to pin, or that they are meant to just extend standard VGA cables. It certainly would be a way to extend the distance between the K3/K3S and the KPA1500, but still retain the functionality between the two. When the new firmware comes out, and the amp can be controlled by the function buttons on the K3 (PF1-operate/stby and PF2-antenna switch), it would be a sure winner. '73 de JIM N2ZZ __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] KPA-1500 Fan Noise
Yes John, and it turns out to be a fairly simple equation if you make a few assumptions. Around 1958 or so and a student [sophomore], I spent the summer with a small crew building KPFK on Mt. Wilson in Los Angeles. The TX was almost totally homebrew [REL serrasoid exciter], with 4 4-1000A's in the PA [4 parallel class-C 4-1000A's at 90.7 Mcs was a bit of a challenge [:-) ]. About to return to school, I was reviewing the physics I'd supposedly learned the previous year and realized I should be able to calculate the efficiency of the PA from the smattering of thermodynamics I knew. Tx engineers don't have much to do until something breaks. I knew the pressure difference between the air inlet and the exhaust [quite small, there was a differential manometer], the filaments dissipated 600 W, nearly all in heat, and I knew the temp difference between the gozinta and gozouta air so I could calculate the mass of the air moving per unit time or so I thought. Then, with the PA on and stable [3.5 A @ ~5.8 KV], I could do it again only this time calculate the power lost to heat the air. Subtract the 600 W from the filaments, and I got 69.4%. I assumed the air was heated at constant pressure, my calculus hadn't progressed far enough to do otherwise. After I went back to school, they finally measured the efficiency on a 2-stage oil/water cooled dummy load and called me and said they got 71.3%. If it doesn't go up the 3 1/8" hardline, it comes out as heat ... somewhere. There's only two options. I'm a little surprised at the obsession with fan noise ... I'd like to hear about how much more DX everyone is working with a KPA1500. 73, Fred ["Skip"] K6DGW Sparks NV DM09dn Washoe County On 6/2/2018 1:06 AM, John Perlick wrote: Bill Schmidt is right--you have to get rid of a bunch of heat--no matter what device you are using to amplify (tubes, transistors, or magic). The amplifying device must dissipate considerable heat because we are running Class AB and because of all electronic devices are naturally lossy. __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] KPA-1500 Fan Noise
After I ordered my kpa1500 back in August I asked that same question to Elecraft. My intent was to make my own AUX cable to put the amp where I wanted.The response was that the AUX BUS can only be so long and it was hinted that about 7 or 8 ft might be the most you should have. Since one AUX cable wouldn'tbe nearly enough I ordered two of them and have the amp where I originally planned to put it. The AUX BUS line is the critical one. BillK3WJV On Saturday, June 2, 2018, 1:46:06 PM EDT, James F. Boehner MD via Elecraft wrote: I would ask someone from Elecraft to respond to the VGA extension cable question. It seems everywhere I read within Elecraft Documentation is that standard VGA cables should NOT be used. In regards to extensions, I do not know if they all work pin to pin, or that they are meant to just extend standard VGA cables. It certainly would be a way to extend the distance between the K3/K3S and the KPA1500, but still retain the functionality between the two. When the new firmware comes out, and the amp can be controlled by the function buttons on the K3 (PF1-operate/stby and PF2-antenna switch), it would be a sure winner. '73 de JIM N2ZZ [Since the cable pin out is straight thru I would imagine a DB15 VGA M-F extension cable would suffice?] -Original Message- From: elecraft-boun...@mailman.qth.net [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of Les Peters Sent: Saturday, June 02, 2018 12:08 PM To: elecraft@mailman.qth.net; elecraft-requ...@mailman.qth.net Subject: Re: [Elecraft] KPA-1500 Fan Noise Jim I agree with your personal observations. I run some high duty cycle modes so I notice the fans kicking into speed 3 a lot when the PA temp gets to 68-70 degrees. That setting does a good job of reducing the temp and keeping it from climbing past 73 degrees. I've changed my min fan speed threshold from 0 to 1 to also help. As you have pointed out 1 is barely perceptible and this helps to reduce the amount of time that fan speeds are on 2+. I'd like to have more separation between the K3S and the KPA1500 RF deck to further distance any noise but the KPAK3AUX cable is only about five feet long, it would be great if that were more like ten feet. Since the cable pin out is straight thru I would imagine a DB15 VGA M-F extension cable would suffice? That would put the potential fan noise even further away but have the RF deck still plenty close enough to view. Les, N1SV #113 > Date: Fri, 1 Jun 2018 23:07:20 -0400 > From: "James F. Boehner MD" > To: "'Elecraft Reflector'" > Subject: [Elecraft] KPA-1500 Fan Noise > Message-ID: <002901d3fa1e$d39e0db0$7ada2910$@yahoo.com mailto:002901d3fa1e$d39e0db0$7ada2910$@yahoo.com > > Content-Type: text/plain; charset="utf-8" > > Just thought I would add a few thoughts as far as the fan noise. > > I'm not certain a YouTube piece would help, but perhaps personal observations might. > > First, via the menu, you can select the minimum fan speed, 0-5. Of course, the fan speed will go up with the Amp temperature. > > These are my personal observations: > > 0-Nothing > 1-Barely perceptible > 2-Acceptable fan noise, even for SSB operating. Low pitched whine > 3-The noise and the pitch of the whine is past the acceptable point. Even a very directional mic will probably pick up the noise. This is where Noise Cancelling headphones would start to help. > 4-Louder and higher pitched whine > 5-Very loud and higher pitched whine > > So, the fan noise becomes particularly bothersome on level 3 and above. If you are doing CW and/or Digital, the noise will only be a factor with the operator. On SSB, the noise will probably be noticeable on the air. However, the SSB duty cycle may not require higher fan speeds. Those who have been active in contests will probably know that answer. > > Rich, if fan noise is going to be that strong a factor, perhaps you should be looking at tube amps instead. Personally, if I found the KPA-1500 fan noise excessive in the future, I would plan on moving it off my desk or remoting it rather than replacing it. It's integration with the K3 would be very hard to give up. > > > ?73 de JIM N2ZZ > #106 > ** > __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to jboehne...@yahoo.com __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net Th
Re: [Elecraft] KPA-1500 Fan Noise
Les, Good advice to check with Elecraft. I believe there are 4 parallel wires for 12V+ and 4 parallel wires for 12V- in the cable. I think most if not all of the 15 pins are used. I believe there is a 12V, 3A supply in the PS box for the RF deck. 73, N2TK, Tony -Original Message- From: elecraft-boun...@mailman.qth.net [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of James F. Boehner MD via Elecraft Sent: Saturday, June 02, 2018 1:43 PM To: elecraft@mailman.qth.net Subject: [Elecraft] KPA-1500 Fan Noise I would ask someone from Elecraft to respond to the VGA extension cable question. It seems everywhere I read within Elecraft Documentation is that standard VGA cables should NOT be used. In regards to extensions, I do not know if they all work pin to pin, or that they are meant to just extend standard VGA cables. It certainly would be a way to extend the distance between the K3/K3S and the KPA1500, but still retain the functionality between the two. When the new firmware comes out, and the amp can be controlled by the function buttons on the K3 (PF1-operate/stby and PF2-antenna switch), it would be a sure winner. '73 de JIM N2ZZ [Since the cable pin out is straight thru I would imagine a DB15 VGA M-F extension cable would suffice?] -Original Message- From: elecraft-boun...@mailman.qth.net [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of Les Peters Sent: Saturday, June 02, 2018 12:08 PM To: elecraft@mailman.qth.net; elecraft-requ...@mailman.qth.net Subject: Re: [Elecraft] KPA-1500 Fan Noise Jim I agree with your personal observations. I run some high duty cycle modes so I notice the fans kicking into speed 3 a lot when the PA temp gets to 68-70 degrees. That setting does a good job of reducing the temp and keeping it from climbing past 73 degrees. I've changed my min fan speed threshold from 0 to 1 to also help. As you have pointed out 1 is barely perceptible and this helps to reduce the amount of time that fan speeds are on 2+. I'd like to have more separation between the K3S and the KPA1500 RF deck to further distance any noise but the KPAK3AUX cable is only about five feet long, it would be great if that were more like ten feet. Since the cable pin out is straight thru I would imagine a DB15 VGA M-F extension cable would suffice? That would put the potential fan noise even further away but have the RF deck still plenty close enough to view. Les, N1SV #113 > Date: Fri, 1 Jun 2018 23:07:20 -0400 > From: "James F. Boehner MD" > To: "'Elecraft Reflector'" > Subject: [Elecraft] KPA-1500 Fan Noise > Message-ID: <002901d3fa1e$d39e0db0$7ada2910$@yahoo.com mailto:002901d3fa1e$d39e0db0$7ada2910$@yahoo.com > > Content-Type: text/plain; charset="utf-8" > > Just thought I would add a few thoughts as far as the fan noise. > > I'm not certain a YouTube piece would help, but perhaps personal observations might. > > First, via the menu, you can select the minimum fan speed, 0-5. Of course, the fan speed will go up with the Amp temperature. > > These are my personal observations: > > 0-Nothing > 1-Barely perceptible > 2-Acceptable fan noise, even for SSB operating. Low pitched whine > 3-The noise and the pitch of the whine is past the acceptable point. Even a very directional mic will probably pick up the noise. This is where Noise Cancelling headphones would start to help. > 4-Louder and higher pitched whine > 5-Very loud and higher pitched whine > > So, the fan noise becomes particularly bothersome on level 3 and above. If you are doing CW and/or Digital, the noise will only be a factor with the operator. On SSB, the noise will probably be noticeable on the air. However, the SSB duty cycle may not require higher fan speeds. Those who have been active in contests will probably know that answer. > > Rich, if fan noise is going to be that strong a factor, perhaps > you should be looking at tube amps instead. Personally, if I found the KPA-1500 fan noise excessive in the future, I would plan on moving it off my desk or remoting it rather than replacing it. It's integration with the K3 would be very hard to give up. > > > ?73 de JIM N2ZZ > #106 > ** > __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to jboehne...@yahoo.com __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net T
Re: [Elecraft] KPA-1500 Fan Noise
Les, A VGA extension will NOT do the job. Get a cable with all 15 pins connected straight through. 73, Don W3FPR On 6/2/2018 12:07 PM, Les Peters wrote: Jim I agree with your personal observations. I run some high duty cycle modes so I notice the fans kicking into speed 3 a lot when the PA temp gets to 68-70 degrees. That setting does a good job of reducing the temp and keeping it from climbing past 73 degrees. I've changed my min fan speed threshold from 0 to 1 to also help. As you have pointed out 1 is barely perceptible and this helps to reduce the amount of time that fan speeds are on 2+. I'd like to have more separation between the K3S and the KPA1500 RF deck to further distance any noise but the KPAK3AUX cable is only about five feet long, it would be great if that were more like ten feet. Since the cable pin out is straight thru I would imagine a DB15 VGA M-F extension cable would suffice? That would put the potential fan noise even further away but have the RF deck still plenty close enough to view. Les, N1SV #113 Date: Fri, 1 Jun 2018 23:07:20 -0400 From: "James F. Boehner MD" To: "'Elecraft Reflector'" Subject: [Elecraft] KPA-1500 Fan Noise Message-ID: <002901d3fa1e$d39e0db0$7ada2910$@yahoo.com mailto:002901d3fa1e$d39e0db0$7ada2910$@yahoo.com > Content-Type: text/plain; charset="utf-8" Just thought I would add a few thoughts as far as the fan noise. I'm not certain a YouTube piece would help, but perhaps personal observations might. First, via the menu, you can select the minimum fan speed, 0-5. Of course, the fan speed will go up with the Amp temperature. These are my personal observations: 0-Nothing 1-Barely perceptible 2-Acceptable fan noise, even for SSB operating. Low pitched whine 3-The noise and the pitch of the whine is past the acceptable point. Even a very directional mic will probably pick up the noise. This is where Noise Cancelling headphones would start to help. 4-Louder and higher pitched whine 5-Very loud and higher pitched whine So, the fan noise becomes particularly bothersome on level 3 and above. If you are doing CW and/or Digital, the noise will only be a factor with the operator. On SSB, the noise will probably be noticeable on the air. However, the SSB duty cycle may not require higher fan speeds. Those who have been active in contests will probably know that answer. Rich, if fan noise is going to be that strong a factor, perhaps you should be looking at tube amps instead. Personally, if I found the KPA-1500 fan noise excessive in the future, I would plan on moving it off my desk or remoting it rather than replacing it. It's integration with the K3 would be very hard to give up. ?73 de JIM N2ZZ #106 ** __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to donw...@embarqmail.com __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] KPA-1500 Fan Noise - YouTube ?
George, there is nothing like Eimac Orange with a glass bottle. RF sunburn :-) Hey, transistors can run pretty hot too, although they should not melt the solder. Case temp can get to 150 deg C and junction temp to 225 deg C. Yes your finger will burn on the case. And yes, the life of many power devices gets derated based on junction temp. As an example an LDMOS may have an MTTF of 1M hours at 150C and 70K hours at 225C junction temp. JANS space transistors are burned in at 220C and tested up to 125C case temp. N2TK, Tony -Original Message- From: elecraft-boun...@mailman.qth.net [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of Gmail - George Sent: Saturday, June 02, 2018 8:10 AM To: elecraft@mailman.qth.net Subject: Re: [Elecraft] KPA-1500 Fan Noise - YouTube ? One other thought to keep in mind - solid state amps need a lower delta T than tube amps. Tubes like to run hot - solid state devices not so much. I've seen a tube with the fins so hot that the solder was in globs, while the transmitter was still operating. I doubt any solid state final would have survived that heat. When we installed our solid state TV transmitter, it was a new learning curve in cooling. Both transmitters were 30 kW class AB1. The tube transmitter moved air faster through 3 tubes but had almost 3 times the temperature rise than the specs for the solid state transmitter. Our HVAC company and architect worked on several complex systems with air mixers until we just decided to use wall mounted air conditioners into the room behind the transmitter racks and exhausted to the front of the transmitters. Our solid state transmitter did meet the OSHA limit for 8 hours exposure to noise but just barely. It was very noisy compared to the tube unit. No tube transmitter I have ever used had a temperature shut down on any of the tube stages. 73 George AI4VZ -Original Message- From: Don Wilhelm Only one bit of correction. If the output power is 1500 watts and the efficiency is 50%, that 1500 watts is only half the total power consumed, so there is 1500 watts of power that must be exhausted as heat. __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to tony@verizon.net __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] KPA-1500 Fan Noise - YouTube ?
Ah, yes ... the desert. Land of rattlesnakes, hairy spiders, and horny toads. We got none of them in Alaska, absolutely no snakes of any flavor, only garden spiders, and only the goldminers are h***. Enough rain to never water the lawn. We got snow, too!! I lived on the edge of the Mojave in Barstow, CA so know the desert. Tuscon is a nice town; visited in 1997. 73, Ed - KL7UW From: Wes Stewart To: elecraft@mailman.qth.net Subject: Re: [Elecraft] KPA-1500 Fan Noise - YouTube ? What's a basement?? On towertalk they talk about letting the lawn grow over ground radials.? I wonder what a lawn is.? They also say to install ground rods where the rain will hit them.? I wonder what rain is. Wes? N7WS 73, Ed - KL7UW http://www.kl7uw.com Dubus-NA Business mail: dubus...@gmail.com __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] KPA-1500 Fan Noise
Jim I agree with your personal observations. I run some high duty cycle modes so I notice the fans kicking into speed 3 a lot when the PA temp gets to 68-70 degrees. That setting does a good job of reducing the temp and keeping it from climbing past 73 degrees. I've changed my min fan speed threshold from 0 to 1 to also help. As you have pointed out 1 is barely perceptible and this helps to reduce the amount of time that fan speeds are on 2+. I'd like to have more separation between the K3S and the KPA1500 RF deck to further distance any noise but the KPAK3AUX cable is only about five feet long, it would be great if that were more like ten feet. Since the cable pin out is straight thru I would imagine a DB15 VGA M-F extension cable would suffice? That would put the potential fan noise even further away but have the RF deck still plenty close enough to view. Les, N1SV #113 > Date: Fri, 1 Jun 2018 23:07:20 -0400 > From: "James F. Boehner MD" > To: "'Elecraft Reflector'" > Subject: [Elecraft] KPA-1500 Fan Noise > Message-ID: <002901d3fa1e$d39e0db0$7ada2910$@yahoo.com > mailto:002901d3fa1e$d39e0db0$7ada2910$@yahoo.com > > Content-Type: text/plain; charset="utf-8" > > Just thought I would add a few thoughts as far as the fan noise. > > I'm not certain a YouTube piece would help, but perhaps personal > observations might. > > First, via the menu, you can select the minimum fan speed, 0-5. Of > course, the fan speed will go up with the Amp temperature. > > These are my personal observations: > > 0-Nothing > 1-Barely perceptible > 2-Acceptable fan noise, even for SSB operating. Low pitched whine > 3-The noise and the pitch of the whine is past the acceptable point. Even > a very directional mic will probably pick up the noise. This is where Noise > Cancelling headphones would start to help. > 4-Louder and higher pitched whine > 5-Very loud and higher pitched whine > > So, the fan noise becomes particularly bothersome on level 3 and above. > If you are doing CW and/or Digital, the noise will only be a factor with the > operator. On SSB, the noise will probably be noticeable on the air. However, > the SSB duty cycle may not require higher fan speeds. Those who have been > active in contests will probably know that answer. > > Rich, if fan noise is going to be that strong a factor, perhaps you > should be looking at tube amps instead. Personally, if I found the KPA-1500 > fan noise excessive in the future, I would plan on moving it off my desk or > remoting it rather than replacing it. It's integration with the K3 would be > very hard to give up. > > > ?73 de JIM N2ZZ > #106 > ** > __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] KPA-1500 Fan Noise
I have a Lunar-LInk System 72 (432 mhz) Amplifier using a pair of 3cx800 (perfectly designed by K1FO SK), in a cubic package that may actually be smaller than the KPA1500 (of course the power supply is external, and the blower and T/R relays are attached to the back of the amp). I had a choice of Dayton blowers, one for ssb/cw (60 CFM if I recall correctly) and one for moon-bounce or key-down modes (100 CFM, I think). I got the 100 CFM blower, anyway the one that moves more air; 100 CFM makes a lot more noise! The only discussion about blower noise was to provide this choice (sometime after I got my unit it became possible to purchase the 100 CFM blower but it ran at two speeds). I imagine that levels 4, and 5 are related to key down modes in KPA1500, and maybe level 3 as well. I suppose one can reduce fan or blower noise to some extent by paying attention to relevant details about fan and noise but all significant variables held constant (like the size of the amp and the power output), there is no free lunch (as usual), solid-state or not. I recall the conduction cooled amps (no fan, no noise), one by Henry Radio (2 x 8873) and another by Heathkit (one 8873). You had to reduce power significantly for key-down modes, and neither amp made 1500 watts output rtty key-down (1000 watts cw for the Henry--but of course this was before the current maximum legal power output). Still, how long you could hold down the key depended upon ventilation of the amplifier. Heathkit recommended only 200 watts output for rtty. I imagine guys placed fans (making some noise) near the heatsinks! So, to put this into perspective, how long the key can be held down using kpa1500 at 1500 watts output power may have something to do with fan speed number five! If you want "almost silent high power", then try running kpa1500 at 500 watts output (about like a conduction cooled amp--but don't hold that key down too long without ventilation). 73, Will. wj9b CWops #1085 CWA Advisor levels II and III http://cwops.org/ CWops #1085 CWA Advisor levels II and III http://cwops.org/ On Sat, 6/2/18, Jim via Elecraft wrote: Subject: Re: [Elecraft] KPA-1500 Fan Noise To: "John Perlick" Cc: "elecraft@mailman.qth.net" Date: Saturday, June 2, 2018, 6:20 AM I don’t have a dog in this fight - someone who spends half the year (the half with all the good contests) in a Florida condo is not a candidate for buying amps. But might water cooling be a possibility? As in a heat sink that sits in water, with appropriate thermal shutoff if the water/amp get too warm? And when that happens, get fresh cool water. 73 - Jim K8MR > On Jun 2, 2018, at 4:06 AM, John Perlick wrote: > > Bill Schmidt is right--you have to get rid of a bunch of heat--no matter what device you are using to amplify (tubes, transistors, or magic). The amplifying device must dissipate considerable heat because we are running Class AB and because of all electronic devices are naturally lossy. > > Remember that this heat is generated not only in the RF transistors, but also in the power supplies, bias circuits, lights, etc. There are lots of heat sources in every amplifier. > > I can honestly say that my KPA1500 is considerably quieter than the Expert 2KFA that I just sold and I would have to say it is quieter than my old Alpha 87A. I do operate it at full 1.5 KW output but I suspect my duty cycle on CW has not caused it to so how that the fans max out. Same for the 2KFA, but even at low speeds, it was far noisier. And, the 2KFA has REALLY loud T/R relays! > __ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:Elecraft@mailman.qth.net > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to jimk...@aol.com __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to wlba...@bellsouth.net __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] KPA-1500 Fan Noise - YouTube ?
While running stations on 160m at a high rate, the finals of an Omni VI got so hot that output dropped to zero. Once the finals cooled for maybe about five minutes, full output returned. We then put a small fan on the heat sink fins and experienced no further problem. No damage at all to the components. Unfortunately, the same Omni VI was hit by lightning some years later. 73, Will, wj9b CWops #1085 CWA Advisor levels II and III http://cwops.org/ On Sat, 6/2/18, Gmail - George wrote: Subject: Re: [Elecraft] KPA-1500 Fan Noise - YouTube ? To: elecraft@mailman.qth.net Date: Saturday, June 2, 2018, 6:10 AM One other thought to keep in mind - solid state amps need a lower delta T than tube amps. Tubes like to run hot - solid state devices not so much. I've seen a tube with the fins so hot that the solder was in globs, while the transmitter was still operating. I doubt any solid state final would have survived that heat. When we installed our solid state TV transmitter, it was a new learning curve in cooling. Both transmitters were 30 kW class AB1. The tube transmitter moved air faster through 3 tubes but had almost 3 times the temperature rise than the specs for the solid state transmitter. Our HVAC company and architect worked on several complex systems with air mixers until we just decided to use wall mounted air conditioners into the room behind the transmitter racks and exhausted to the front of the transmitters. Our solid state transmitter did meet the OSHA limit for 8 hours exposure to noise but just barely. It was very noisy compared to the tube unit. No tube transmitter I have ever used had a temperature shut down on any of the tube stages. 73 George AI4VZ -Original Message- From: Don Wilhelm Only one bit of correction. If the output power is 1500 watts and the efficiency is 50%, that 1500 watts is only half the total power consumed, so there is 1500 watts of power that must be exhausted as heat. __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to wlba...@bellsouth.net __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] KPA-1500 Fan Noise
I don’t have a dog in this fight - someone who spends half the year (the half with all the good contests) in a Florida condo is not a candidate for buying amps. But might water cooling be a possibility? As in a heat sink that sits in water, with appropriate thermal shutoff if the water/amp get too warm? And when that happens, get fresh cool water. 73 - Jim K8MR > On Jun 2, 2018, at 4:06 AM, John Perlick wrote: > > Bill Schmidt is right--you have to get rid of a bunch of heat--no matter what > device you are using to amplify (tubes, transistors, or magic). The > amplifying device must dissipate considerable heat because we are running > Class AB and because of all electronic devices are naturally lossy. > > Remember that this heat is generated not only in the RF transistors, but also > in the power supplies, bias circuits, lights, etc. There are lots of heat > sources in every amplifier. > > I can honestly say that my KPA1500 is considerably quieter than the Expert > 2KFA that I just sold and I would have to say it is quieter than my old Alpha > 87A. I do operate it at full 1.5 KW output but I suspect my duty cycle on CW > has not caused it to so how that the fans max out. Same for the 2KFA, but > even at low speeds, it was far noisier. And, the 2KFA has REALLY loud T/R > relays! > __ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:Elecraft@mailman.qth.net > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to jimk...@aol.com __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] KPA-1500 Fan Noise - YouTube ?
One other thought to keep in mind - solid state amps need a lower delta T than tube amps. Tubes like to run hot - solid state devices not so much. I've seen a tube with the fins so hot that the solder was in globs, while the transmitter was still operating. I doubt any solid state final would have survived that heat. When we installed our solid state TV transmitter, it was a new learning curve in cooling. Both transmitters were 30 kW class AB1. The tube transmitter moved air faster through 3 tubes but had almost 3 times the temperature rise than the specs for the solid state transmitter. Our HVAC company and architect worked on several complex systems with air mixers until we just decided to use wall mounted air conditioners into the room behind the transmitter racks and exhausted to the front of the transmitters. Our solid state transmitter did meet the OSHA limit for 8 hours exposure to noise but just barely. It was very noisy compared to the tube unit. No tube transmitter I have ever used had a temperature shut down on any of the tube stages. 73 George AI4VZ -Original Message- From: Don Wilhelm Only one bit of correction. If the output power is 1500 watts and the efficiency is 50%, that 1500 watts is only half the total power consumed, so there is 1500 watts of power that must be exhausted as heat. __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] KPA-1500 Fan Noise - YouTube ?
Wes, tnx for the chuckle. No lawn mower, no umbrella, no place to store unwanted and unnecessary junk. You are livin' a dream. And you can string your dipoles from the Saguaro. Hey, if the arms are the correct lengths you can string some verticals to cover multiple bands. And if the arms are the same length maybe you can make a phased array? I don't miss being entertained by the rattlers and Javelinas on the golf course in Tucson. 73, N2TK, Tony -Original Message- From: elecraft-boun...@mailman.qth.net [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of Wes Stewart Sent: Friday, June 01, 2018 9:28 PM To: elecraft@mailman.qth.net Subject: Re: [Elecraft] KPA-1500 Fan Noise - YouTube ? What's a basement? On towertalk they talk about letting the lawn grow over ground radials. I wonder what a lawn is. They also say to install ground rods where the rain will hit them. I wonder what rain is. Wes N7WS On 6/1/2018 6:05 PM, hawley, charles j jr wrote: > Some years ago we cooled a PDP11 by putting the fan remote and running a > dryer hose to the computer. How about putting the fan in the basement and the > rig on the desk where it’s handy? > > Chuck Jack > KE9UW __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to tony@verizon.net __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] KPA-1500 Fan Noise
Bill Schmidt is right--you have to get rid of a bunch of heat--no matter what device you are using to amplify (tubes, transistors, or magic). The amplifying device must dissipate considerable heat because we are running Class AB and because of all electronic devices are naturally lossy. Remember that this heat is generated not only in the RF transistors, but also in the power supplies, bias circuits, lights, etc. There are lots of heat sources in every amplifier. I can honestly say that my KPA1500 is considerably quieter than the Expert 2KFA that I just sold and I would have to say it is quieter than my old Alpha 87A. I do operate it at full 1.5 KW output but I suspect my duty cycle on CW has not caused it to so how that the fans max out. Same for the 2KFA, but even at low speeds, it was far noisier. And, the 2KFA has REALLY loud T/R relays! __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] KPA-1500 Fan Noise - YouTube ?
Only one bit of correction. If the output power is 1500 watts and the efficiency is 50%, that 1500 watts is only half the total power consumed, so there is 1500 watts of power that must be exhausted as heat. Yes, it is all thermodynamics, that heat must be dissipated somehow. Fans are the obvious solution. 73, Don W3FPR On 6/1/2018 8:59 PM, Dr. William J. Schmidt wrote: So just a bit of thermodynamics... if the input to any amplifier is 1500 watts and it is 50% efficient, since energy is conserved, 750 watts will come out in another form.. and in this case it's heat. Doesn't matter what the converter is (transistor, tube, resistor, etc.). It all behaves the same. Need to get rid of 750 watts of heat. The only difference may be the way the heat is taken away of the converter... convection (heat sink), forced convection (heat skin plus fan), liquid convection (water cooled heat sink). The poison is the heat removal device not the converter. Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ PJ2/K9HZ Owner - Operator Big Signal Ranch – K9ZC Staunton, Illinois Owner – Operator Villa Grand Piton – J68HZ Soufriere, St. Lucia W.I. Rent it: www.VillaGrandPiton.com Like us on Facebook! Moderator – North American QRO Group at Groups.IO. email: b...@wjschmidt.com -Original Message- From: elecraft-boun...@mailman.qth.net [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of Bill Stravinsky via Elecraft Sent: Friday, June 1, 2018 7:33 PM To: Elecraft Reflector Subject: Re: [Elecraft] KPA-1500 Fan Noise - YouTube ? Rich You pretty much hit the nail on the head about solid state amps. As they say there's no free lunch. Solid state has made great strides in high power ampsbut its still solid state and a p/n junction or some form thereof. 1500 watts of heat in those junctions has to be cooled down or it won't be long before it needsnew parts. Depending on your operating habits (contesting, casual, or whatever) there will be varying degrees of fan noise. The higher the duty cycle the higher thefan requirements. Pick your poison, a small light weight amp easy to move around or one you need a fork lift to pick up. I prefer tube amps for a few reasonsand have the Acom 2000a (and an Alpha 89 that now sits in the living room temporarily) but I'm still glad I got the kpa1500 at least so far. The kpa sits nicely on top of the Acom without causing the table they sit on to crash to the floor in pieces, hi. I'm surprised nobody has made a you tube ofthe amp in operation actually. But there are only just over 200 of the new amps out there. Good luck with your investigation, Rich. BillK3WJV On Friday, June 1, 2018, 8:00:29 PM EDT, Richard Thorne wrote: This fan noise issue has me concerned to the point that I’m considering cancelling my order. While the amp won’t be on my operating desk, it will be on a rack next to my operating desk. Remoting the amp is not an option. Quite frankly I have no interest in remoting the amp. Is there anyone out there that has a KPA-1500 willing to post a YouTube video so we can hear the fan in action and judge the noise for ourselves? From the research I’ve done it appears that if you want a solid state amp, regardless of make, you need to be prepared for fan noise. Thanks Rich - N5ZC Sent from my iPhone __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to k3...@yahoo.com __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to b...@wjschmidt.com --- This email has been checked for viruses by AVG. https://www.avg.com __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to donw...@embarqmail.com __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] KPA-1500 Fan Noise - YouTube ?
I personally think all the banter about KPA1500 fan noise has created confusion. Yes, the amp has three fans with five selectable fan speeds..and since the amp is small the fans are necessarily small and therefore must run faster …. and as the fan speed increases the pitch and noise levels increase.. and the higher fan speeds do indeed create significant noise, but the higher speeds will rarely (if ever) be needed. I have had my KPA1500 about 3 months now, and have manually switched to level 3 just a couple times (cq running during cw contest and major cw split pileup), and thus far I have never had to use levels 4 or 5. The fans operate automatically as per heat sink temperature but can also be manually controlled. Fan speeds 1 and 2, to me, are just like any other amplifier, and noise is not problematic. Levels 3, 4, and 5 however are definitely noisy and can become annoying…. But again, those speeds are rarely necessary. IMHO, with five selectable speeds, the KPA1500 could very likely have the most capable cooling system available in any amateur amplifier and I call that a plus. The three additional amplifiers in my shack (Alpha 9500, Icom PA1 and Alpha 89) make noise too, but it’s probably a good bet that they do not have cooling capability that matches the KPA1500’s five speed fans. Don, N5LZ -Original Message- From: elecraft-boun...@mailman.qth.net [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of Richard Thorne Sent: Friday, June 01, 2018 5:55 PM To: Elecraft@mailman.qth.net Subject: [Elecraft] KPA-1500 Fan Noise - YouTube ? This fan noise issue has me concerned to the point that I’m considering cancelling my order. While the amp won’t be on my operating desk, it will be on a rack next to my operating desk. Remoting the amp is not an option. Quite frankly I have no interest in remoting the amp. Is there anyone out there that has a KPA-1500 willing to post a YouTube video so we can hear the fan in action and judge the noise for ourselves? From the research I’ve done it appears that if you want a solid state amp, regardless of make, you need to be prepared for fan noise. Thanks Rich - N5ZC Sent from my iPhone __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to n...@comcast.net __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] KPA-1500 Fan Noise - YouTube ?
What's a basement? On towertalk they talk about letting the lawn grow over ground radials. I wonder what a lawn is. They also say to install ground rods where the rain will hit them. I wonder what rain is. Wes N7WS On 6/1/2018 6:05 PM, hawley, charles j jr wrote: Some years ago we cooled a PDP11 by putting the fan remote and running a dryer hose to the computer. How about putting the fan in the basement and the rig on the desk where it’s handy? Chuck Jack KE9UW __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] KPA-1500 Fan Noise - YouTube ?
Tube amp just has the single fan that doesn't spin at 9000 rpm like the little solid state fans, hi. Same noise level if xmit or not. BillK3WJV On Friday, June 1, 2018, 9:04:45 PM EDT, Dr. William J. Schmidt wrote: So just a bit of thermodynamics... if the input to any amplifier is 1500 watts and it is 50% efficient, since energy is conserved, 750 watts will come out in another form.. and in this case it's heat. Doesn't matter what the converter is (transistor, tube, resistor, etc.). It all behaves the same. Need to get rid of 750 watts of heat. The only difference may be the way the heat is taken away of the converter... convection (heat sink), forced convection (heat skin plus fan), liquid convection (water cooled heat sink). The poison is the heat removal device not the converter. Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ PJ2/K9HZ Owner - Operator Big Signal Ranch – K9ZC Staunton, Illinois Owner – Operator Villa Grand Piton – J68HZ Soufriere, St. Lucia W.I. Rent it: www.VillaGrandPiton.com Like us on Facebook! Moderator – North American QRO Group at Groups.IO. email: b...@wjschmidt.com -Original Message- From: elecraft-boun...@mailman.qth.net [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of Bill Stravinsky via Elecraft Sent: Friday, June 1, 2018 7:33 PM To: Elecraft Reflector Subject: Re: [Elecraft] KPA-1500 Fan Noise - YouTube ? Rich You pretty much hit the nail on the head about solid state amps. As they say there's no free lunch. Solid state has made great strides in high power ampsbut its still solid state and a p/n junction or some form thereof. 1500 watts of heat in those junctions has to be cooled down or it won't be long before it needsnew parts. Depending on your operating habits (contesting, casual, or whatever) there will be varying degrees of fan noise. The higher the duty cycle the higher thefan requirements. Pick your poison, a small light weight amp easy to move around or one you need a fork lift to pick up. I prefer tube amps for a few reasonsand have the Acom 2000a (and an Alpha 89 that now sits in the living room temporarily) but I'm still glad I got the kpa1500 at least so far. The kpa sits nicely on top of the Acom without causing the table they sit on to crash to the floor in pieces, hi. I'm surprised nobody has made a you tube ofthe amp in operation actually. But there are only just over 200 of the new amps out there. Good luck with your investigation, Rich. BillK3WJV On Friday, June 1, 2018, 8:00:29 PM EDT, Richard Thorne wrote: This fan noise issue has me concerned to the point that I’m considering cancelling my order. While the amp won’t be on my operating desk, it will be on a rack next to my operating desk. Remoting the amp is not an option. Quite frankly I have no interest in remoting the amp. Is there anyone out there that has a KPA-1500 willing to post a YouTube video so we can hear the fan in action and judge the noise for ourselves? From the research I’ve done it appears that if you want a solid state amp, regardless of make, you need to be prepared for fan noise. Thanks Rich - N5ZC Sent from my iPhone __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to k3...@yahoo.com __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to b...@wjschmidt.com --- This email has been checked for viruses by AVG. https://www.avg.com __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to k3...@yahoo.com __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] KPA-1500 Fan Noise - YouTube ?
Some years ago we cooled a PDP11 by putting the fan remote and running a dryer hose to the computer. How about putting the fan in the basement and the rig on the desk where it’s handy? Chuck Jack KE9UW Sent from my iPhone, cjack > On Jun 1, 2018, at 7:57 PM, Michael Walker wrote: > > Bill is correct > > You have to move air to cool down those devices and it takes fans to do > it. Water cooling might work if you wish to modify it. :) > > But, there is no free lunch as was mentioned. Be prepared that any 1500 > watt LMDOS amp requires cooling but since there is no tube, they are built > in smaller boxes, so you get smaller fans that have to move more air. > > The B26 is somewhat quieter I think, but they worked on some things to make > it quieter like extending the fan out the back so there is less disturbed > air when it hits the fan blades. > > They aren't that loud and if were good headphones, you won't notice at all. > > my 2 cents, Mike va3mw > > > On Fri, Jun 1, 2018 at 8:32 PM, Bill Stravinsky via Elecraft < > elecraft@mailman.qth.net> wrote: > >> Rich >> >> You pretty much hit the nail on the head about solid state amps. As they >> say there's no free lunch. Solid state has made great strides in high >> power ampsbut its still solid state and a p/n junction or some form >> thereof. 1500 watts of heat in those junctions has to be cooled down or it >> won't be long before it needsnew parts. >> Depending on your operating habits (contesting, casual, or whatever) there >> will be varying degrees of fan noise. The higher the duty cycle the higher >> thefan requirements. Pick your poison, a small light weight amp easy to >> move around or one you need a fork lift to pick up. I prefer tube amps for >> a few reasonsand have the Acom 2000a (and an Alpha 89 that now sits in the >> living room temporarily) but I'm still glad I got the kpa1500 at least so >> far. >> The kpa sits nicely on top of the Acom without causing the table they sit >> on to crash to the floor in pieces, hi. I'm surprised nobody has made a >> you tube ofthe amp in operation actually. But there are only just over 200 >> of the new amps out there. Good luck with your investigation, Rich. >> BillK3WJV >> >>On Friday, June 1, 2018, 8:00:29 PM EDT, Richard Thorne < >> rtho...@rthorne.net> wrote: >> >> This fan noise issue has me concerned to the point that I’m considering >> cancelling my order. >> >> While the amp won’t be on my operating desk, it will be on a rack next to >> my operating desk. Remoting the amp is not an option. Quite frankly I have >> no interest in remoting the amp. >> >> Is there anyone out there that has a KPA-1500 willing to post a YouTube >> video so we can hear the fan in action and judge the noise for ourselves? >> >> From the research I’ve done it appears that if you want a solid state amp, >> regardless of make, you need to be prepared for fan noise. >> >> Thanks >> >> Rich - N5ZC >> >> Sent from my iPhone >> __ >> Elecraft mailing list >> Home: http://mailman.qth.net/mailman/listinfo/elecraft >> Help: http://mailman.qth.net/mmfaq.htm >> Post: mailto:Elecraft@mailman.qth.net >> >> This list hosted by: http://www.qsl.net >> Please help support this email list: http://www.qsl.net/donate.html >> Message delivered to k3...@yahoo.com >> __ >> Elecraft mailing list >> Home: http://mailman.qth.net/mailman/listinfo/elecraft >> Help: http://mailman.qth.net/mmfaq.htm >> Post: mailto:Elecraft@mailman.qth.net >> >> This list hosted by: http://www.qsl.net >> Please help support this email list: http://www.qsl.net/donate.html >> Message delivered to va...@portcredit.net >> > __ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:Elecraft@mailman.qth.net > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to c-haw...@illinois.edu __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] KPA-1500 Fan Noise - YouTube ?
So just a bit of thermodynamics... if the input to any amplifier is 1500 watts and it is 50% efficient, since energy is conserved, 750 watts will come out in another form.. and in this case it's heat. Doesn't matter what the converter is (transistor, tube, resistor, etc.). It all behaves the same. Need to get rid of 750 watts of heat. The only difference may be the way the heat is taken away of the converter... convection (heat sink), forced convection (heat skin plus fan), liquid convection (water cooled heat sink). The poison is the heat removal device not the converter. Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ PJ2/K9HZ Owner - Operator Big Signal Ranch – K9ZC Staunton, Illinois Owner – Operator Villa Grand Piton – J68HZ Soufriere, St. Lucia W.I. Rent it: www.VillaGrandPiton.com Like us on Facebook! Moderator – North American QRO Group at Groups.IO. email: b...@wjschmidt.com -Original Message- From: elecraft-boun...@mailman.qth.net [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of Bill Stravinsky via Elecraft Sent: Friday, June 1, 2018 7:33 PM To: Elecraft Reflector Subject: Re: [Elecraft] KPA-1500 Fan Noise - YouTube ? Rich You pretty much hit the nail on the head about solid state amps. As they say there's no free lunch. Solid state has made great strides in high power ampsbut its still solid state and a p/n junction or some form thereof. 1500 watts of heat in those junctions has to be cooled down or it won't be long before it needsnew parts. Depending on your operating habits (contesting, casual, or whatever) there will be varying degrees of fan noise. The higher the duty cycle the higher thefan requirements. Pick your poison, a small light weight amp easy to move around or one you need a fork lift to pick up. I prefer tube amps for a few reasonsand have the Acom 2000a (and an Alpha 89 that now sits in the living room temporarily) but I'm still glad I got the kpa1500 at least so far. The kpa sits nicely on top of the Acom without causing the table they sit on to crash to the floor in pieces, hi. I'm surprised nobody has made a you tube ofthe amp in operation actually. But there are only just over 200 of the new amps out there. Good luck with your investigation, Rich. BillK3WJV On Friday, June 1, 2018, 8:00:29 PM EDT, Richard Thorne wrote: This fan noise issue has me concerned to the point that I’m considering cancelling my order. While the amp won’t be on my operating desk, it will be on a rack next to my operating desk. Remoting the amp is not an option. Quite frankly I have no interest in remoting the amp. Is there anyone out there that has a KPA-1500 willing to post a YouTube video so we can hear the fan in action and judge the noise for ourselves? From the research I’ve done it appears that if you want a solid state amp, regardless of make, you need to be prepared for fan noise. Thanks Rich - N5ZC Sent from my iPhone __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to k3...@yahoo.com __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to b...@wjschmidt.com --- This email has been checked for viruses by AVG. https://www.avg.com __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] KPA-1500 Fan Noise - YouTube ?
Bill is correct You have to move air to cool down those devices and it takes fans to do it. Water cooling might work if you wish to modify it. :) But, there is no free lunch as was mentioned. Be prepared that any 1500 watt LMDOS amp requires cooling but since there is no tube, they are built in smaller boxes, so you get smaller fans that have to move more air. The B26 is somewhat quieter I think, but they worked on some things to make it quieter like extending the fan out the back so there is less disturbed air when it hits the fan blades. They aren't that loud and if were good headphones, you won't notice at all. my 2 cents, Mike va3mw On Fri, Jun 1, 2018 at 8:32 PM, Bill Stravinsky via Elecraft < elecraft@mailman.qth.net> wrote: > Rich > > You pretty much hit the nail on the head about solid state amps. As they > say there's no free lunch. Solid state has made great strides in high > power ampsbut its still solid state and a p/n junction or some form > thereof. 1500 watts of heat in those junctions has to be cooled down or it > won't be long before it needsnew parts. > Depending on your operating habits (contesting, casual, or whatever) there > will be varying degrees of fan noise. The higher the duty cycle the higher > thefan requirements. Pick your poison, a small light weight amp easy to > move around or one you need a fork lift to pick up. I prefer tube amps for > a few reasonsand have the Acom 2000a (and an Alpha 89 that now sits in the > living room temporarily) but I'm still glad I got the kpa1500 at least so > far. > The kpa sits nicely on top of the Acom without causing the table they sit > on to crash to the floor in pieces, hi. I'm surprised nobody has made a > you tube ofthe amp in operation actually. But there are only just over 200 > of the new amps out there. Good luck with your investigation, Rich. > BillK3WJV > > On Friday, June 1, 2018, 8:00:29 PM EDT, Richard Thorne < > rtho...@rthorne.net> wrote: > > This fan noise issue has me concerned to the point that I’m considering > cancelling my order. > > While the amp won’t be on my operating desk, it will be on a rack next to > my operating desk. Remoting the amp is not an option. Quite frankly I have > no interest in remoting the amp. > > Is there anyone out there that has a KPA-1500 willing to post a YouTube > video so we can hear the fan in action and judge the noise for ourselves? > > From the research I’ve done it appears that if you want a solid state amp, > regardless of make, you need to be prepared for fan noise. > > Thanks > > Rich - N5ZC > > Sent from my iPhone > __ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:Elecraft@mailman.qth.net > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to k3...@yahoo.com > __ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:Elecraft@mailman.qth.net > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to va...@portcredit.net > __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] KPA-1500 Fan Noise - YouTube ?
Rich You pretty much hit the nail on the head about solid state amps. As they say there's no free lunch. Solid state has made great strides in high power ampsbut its still solid state and a p/n junction or some form thereof. 1500 watts of heat in those junctions has to be cooled down or it won't be long before it needsnew parts. Depending on your operating habits (contesting, casual, or whatever) there will be varying degrees of fan noise. The higher the duty cycle the higher thefan requirements. Pick your poison, a small light weight amp easy to move around or one you need a fork lift to pick up. I prefer tube amps for a few reasonsand have the Acom 2000a (and an Alpha 89 that now sits in the living room temporarily) but I'm still glad I got the kpa1500 at least so far. The kpa sits nicely on top of the Acom without causing the table they sit on to crash to the floor in pieces, hi. I'm surprised nobody has made a you tube ofthe amp in operation actually. But there are only just over 200 of the new amps out there. Good luck with your investigation, Rich. BillK3WJV On Friday, June 1, 2018, 8:00:29 PM EDT, Richard Thorne wrote: This fan noise issue has me concerned to the point that I’m considering cancelling my order. While the amp won’t be on my operating desk, it will be on a rack next to my operating desk. Remoting the amp is not an option. Quite frankly I have no interest in remoting the amp. Is there anyone out there that has a KPA-1500 willing to post a YouTube video so we can hear the fan in action and judge the noise for ourselves? From the research I’ve done it appears that if you want a solid state amp, regardless of make, you need to be prepared for fan noise. Thanks Rich - N5ZC Sent from my iPhone __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to k3...@yahoo.com __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
