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I have had my la-1k for a few years now, and it has never gotten hot in SSB use (usually <500 W). I have recently found out how to solve a problem I had with it constantly going into SWR bypass in a digital mode, so am now trying to get some use out of it there. For the short transmission modes and activities it will likely be fine, however I do some nets and operations that have longer transmission times - sometimes more than a minute or maybe even two minutes. Obviously this is really a 100% duty cycle, but I am only driving it with 5 watts to get about 125 watts output. I am happy with that level of output, but when I made a longer transmission the temp quickly climbed up to 80 C! Fortunately that was the end of the message, or I would have had to terminate it. I am driving an 80m double bazooka single-band antenna with a native SWR of 1.02. The meter on the amp says 1.0. As a side note if I go through my HF-AUTO tuner, it shows a low SWR also, but the amp shows 1.2 or 1.3. I often see this when I use the tuner, the amp SWR is always about .1 to .3 higher than the tuner is showing. Given the nature of my digital operations I think it is better to just go direct to the antenna.
Any thoughts or suggestion would be great.? 73's
Al
KD2PNR
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I actually have a small fan sitting next to the amp which I have found helps the quick temperature rise.
I have had my la-1k for a few years now, and it has never gotten hot in SSB use (usually <500 W). I have recently found out how to solve a problem I had with it constantly going into SWR bypass in a digital mode, so am now trying to get some use out of it there. For the short transmission modes and activities it will likely be fine, however I do some nets and operations that have longer transmission times - sometimes more than a minute or maybe even two minutes. Obviously this is really a 100% duty cycle, but I am only driving it with 5 watts to get about 125 watts output. I am happy with that level of output, but when I made a longer transmission the temp quickly climbed up to 80 C! Fortunately that was the end of the message, or I would have had to terminate it. I am driving an 80m double bazooka single-band antenna with a native SWR of 1.02. The meter on the amp says 1.0. As a side note if I go through my HF-AUTO tuner, it shows a low SWR also, but the amp shows 1.2 or 1.3. I often see this when I use the tuner, the amp SWR is always about .1 to .3 higher than the tuner is showing. Given the nature of my digital operations I think it is better to just go direct to the antenna.
Any thoughts or suggestion would be great.? 73's
Al
KD2PNR
-- ? ?? Rev. Terry N. Hursh, M.Div, J.D
5 Rapallo Mews. Mississauga . ON L5N 1K8 Canada
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Certain bands show the same quick rise in temperature, some other bands rise slower, but I pretty much have to stop operating digital modes after about 10 to 15 minutes. ? 2 QSOs on 40M are enough to get temp to the point were the first loud fan starts, after 10 minutes or less the next level fans start at 63 degrees C, by then I usually stop, because the noise level of the fans is really annoying. ? 73, Bernd – KB7AK ?
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From: [email protected] < [email protected]> On Behalf Of Terry Hursh Sent: Monday, January 30, 2023 3:26 PM To: [email protected]Subject: Re: [la1k] Digital modes and fast temperature rise ? I actually have a small fan sitting next to the amp which I have found helps the quick temperature rise. ? I have had my la-1k for a few years now, and it has never gotten hot in SSB use (usually <500 W). I have recently found out how to solve a problem I had with it constantly going into SWR bypass in a digital mode, so am now trying to get some use out of it there. For the short transmission modes and activities it will likely be fine, however I do some nets and operations that have longer transmission times - sometimes more than a minute or maybe even two minutes. Obviously this is really a 100% duty cycle, but I am only driving it with 5 watts to get about 125 watts output. I am happy with that level of output, but when I made a longer transmission the temp quickly climbed up to 80 C! Fortunately that was the end of the message, or I would have had to terminate it. I am driving an 80m double bazooka single-band antenna with a native SWR of 1.02. The meter on the amp says 1.0. As a side note if I go through my HF-AUTO tuner, it shows a low SWR also, but the amp shows 1.2 or 1.3. I often see this when I use the tuner, the amp SWR is always about .1 to .3 higher than the tuner is showing. Given the nature of my digital operations I think it is better to just go direct to the antenna.
Any thoughts or suggestion would be great.? 73's
Al
KD2PNR
-- ???Rev. Terry N. Hursh, M.Div, J.D 5 Rapallo Mews. Mississauga . ON L5N 1K8 Canada
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Al,
Is the amp suckling on 120V or 240V??? I'm still on 120V, but
from what I understand, the amp will run hotter, hence fans will
run more.? My Elmer also has the LA-1K, but on 240V, and we have
operated for hours on it, without hardly hearing the fan.? The
only comparison I have is with his, and seems to run cooler on
240V.
My 2?
73 David
On 1/30/2023 5:46 PM, Bernd - KB7AK
wrote:
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Certain bands show the same quick rise in
temperature, some other bands rise slower, but I pretty much
have to stop operating digital modes after about 10 to 15
minutes.
?
2 QSOs on 40M are enough to get temp to the
point were the first loud fan starts, after 10 minutes or less
the next level fans start at 63 degrees C, by then I usually
stop, because the noise level of the fans is really annoying.
?
73,
Bernd – KB7AK
?
?
I actually have a small fan sitting next
to the amp which I have found helps the quick temperature
rise.
?
I have had my la-1k for a few years
now, and it has never gotten hot in SSB use (usually
<500 W). I have recently found out how to solve a
problem I had with it constantly going into SWR bypass in
a digital mode, so am now trying to get some use out of it
there. For the short transmission modes and activities it
will likely be fine, however I do some nets and operations
that have longer transmission times - sometimes more than
a minute or maybe even two minutes. Obviously this is
really a 100% duty cycle, but I am only driving it with 5
watts to get about 125 watts output. I am happy with that
level of output, but when I made a longer transmission the
temp quickly climbed up to 80 C! Fortunately that was the
end of the message, or I would have had to terminate it. I
am driving an 80m double bazooka single-band antenna with
a native SWR of 1.02. The meter on the amp says 1.0. As a
side note if I go through my HF-AUTO tuner, it shows a low
SWR also, but the amp shows 1.2 or 1.3. I often see this
when I use the tuner, the amp SWR is always about .1 to .3
higher than the tuner is showing. Given the nature of my
digital operations I think it is better to just go direct
to the antenna.
Any thoughts or suggestion would be great.? 73's
Al
KD2PNR
--
???Rev.
Terry N. Hursh, M.Div, J.D
5
Rapallo Mews. Mississauga . ON L5N 1K8 Canada
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Hi all, Regarding heat and my la1k:? I push about 350 watts using ft8 and the temp in my amp (regardless of band) climbs to 64 degrees C.? I have the amp sitting in a plenum with four thermostatically controlled fans pushing air at about 700cpm.? This works very well. ? Scott Sherer KC9WPS ?
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From: [email protected] [mailto:[email protected]] On Behalf Of Terry Hursh
Sent: Monday, January 30, 2023 5:26 PM
To: [email protected]
Subject: Re: [la1k] Digital modes and fast temperature rise ? I actually have a small fan sitting next to the amp which I have found helps the quick temperature rise. ? I have had my la-1k for a few years now, and it has never gotten hot in SSB use (usually <500 W). I have recently found out how to solve a problem I had with it constantly going into SWR bypass in a digital mode, so am now trying to get some use out of it there. For the short transmission modes and activities it will likely be fine, however I do some nets and operations that have longer transmission times - sometimes more than a minute or maybe even two minutes. Obviously this is really a 100% duty cycle, but I am only driving it with 5 watts to get about 125 watts output. I am happy with that level of output, but when I made a longer transmission the temp quickly climbed up to 80 C! Fortunately that was the end of the message, or I would have had to terminate it. I am driving an 80m double bazooka single-band antenna with a native SWR of 1.02. The meter on the amp says 1.0. As a side note if I go through my HF-AUTO tuner, it shows a low SWR also, but the amp shows 1.2 or 1.3. I often see this when I use the tuner, the amp SWR is always about .1 to .3 higher than the tuner is showing. Given the nature of my digital operations I think it is better to just go direct to the antenna.
Any thoughts or suggestion would be great.? 73's
Al
KD2PNR
-- ???Rev. Terry N. Hursh, M.Div, J.D 5 Rapallo Mews. Mississauga . ON L5N 1K8 Canada
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Interesting observations all around. I run on 240, so there is no improvement to be gained there. As my temps rise the fans shift through the 3 levels, with the last one being very loud indeed. This is not a quiet amp, even when not in use. Perhaps I will give FT8 a try just to collect a data point, but I don't really use that mode at all. I must say I am very disappointed in this amp, what with the noise levels and the heat problems. I would have thought that running it at such low levels would have been easy, but I guess not. Next option is to look into the cooling setup as it now stands, and what could be done to improve on it.
Thanks again for the information updates.
Al
KD2PNR
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There's really no reason to be disappointed because the AMP
really holds its value well if you wanted to sell it. The really
good news is the AMP market is fairly saturated meaning there are
a lot of good choices out there.? Perhaps there's an amp out there
that will work the way you need it to. If it were me, and I didn't
get what I expected, I would be selling or asking for a refund.
The amount of money these guys cost is a lot, and imagine there's
buyers remorse out there too.? ? My recommendation is to not
settle, and get what you want and deserve for the money.
Best Regards, 73? David
?
On 1/30/2023 7:32 PM, Al - KD2PNR via
groups.io wrote:
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Interesting observations all around. I run on 240, so there is no
improvement to be gained there. As my temps rise the fans shift
through the 3 levels, with the last one being very loud indeed.
This is not a quiet amp, even when not in use. Perhaps I will give
FT8 a try just to collect a data point, but I don't really use
that mode at all. I must say I am very disappointed in this amp,
what with the noise levels and the heat problems. I would have
thought that running it at such low levels would have been easy,
but I guess not. Next option is to look into the cooling setup as
it now stands, and what could be done to improve on it.
Thanks again for the information updates.
Al
KD2PNR
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Cooling issues: high level gamers use liquid cooled processors and innovative heatsinks. Ham radio is all about innovation, so maybe you digital guys might take a page from their book and make some mods…i haven't used my?LA1K that hard so I am only postulating. Would be interested to know how that could be incorporated.? 73
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On Jan 30, 2023, at 7:48 PM, David Campeau <davidc502@...> wrote:
?
There's really no reason to be disappointed because the AMP
really holds its value well if you wanted to sell it. The really
good news is the AMP market is fairly saturated meaning there are
a lot of good choices out there.? Perhaps there's an amp out there
that will work the way you need it to. If it were me, and I didn't
get what I expected, I would be selling or asking for a refund.
The amount of money these guys cost is a lot, and imagine there's
buyers remorse out there too.? ? My recommendation is to not
settle, and get what you want and deserve for the money.
Best Regards, 73? David
?
On 1/30/2023 7:32 PM, Al - KD2PNR via
groups.io wrote:
Interesting observations all around. I run on 240, so there is no
improvement to be gained there. As my temps rise the fans shift
through the 3 levels, with the last one being very loud indeed.
This is not a quiet amp, even when not in use. Perhaps I will give
FT8 a try just to collect a data point, but I don't really use
that mode at all. I must say I am very disappointed in this amp,
what with the noise levels and the heat problems. I would have
thought that running it at such low levels would have been easy,
but I guess not. Next option is to look into the cooling setup as
it now stands, and what could be done to improve on it.
Thanks again for the information updates.
Al
KD2PNR
|
Scott - Don't recall ever meeting you, but we are not far apart.
My LA-1K went back for warranty service two years ago.? While there it was upgraded with quieter T/R relay and fans (at a reasonable cost), but they mentioned cooling with the new fans was not quite as good.? They even returned my originals, should I wish to change them back.? My amp runs on 120V and will occasionally peak above 1000w on SSB phone.? I generally drive it with 45 watts, and get about 850w out.? On phone, it will warm (worse on higher frequencies), but even in contest mode will be OK, temperature wise.
But it's another story on FT-8, where prolonged use on 10 meters is limited to about 175-200 watts, with temp stabilizing above 70+ deg C.? Lower band FT8 will be OK at 250w, with stable temp operation in 60 deg range - although I normally don't run that high.? I'm also careful to never hit 80 degrees.? Other that what I consider to be excess temperature rise, the Amp seems to work fine.? Someday I should phone Palstar and see if they have other comments.
Without your additional plenum, were your FT8 temperatures similar to mine?? 10 meters has been super recently, and seems to be where my amp runs the hottest.
73 .... Fred,? W9KEY
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With the duty cycle of digital, I treat it as AM and run at about 125W output.
I don't run FT8 that constantly runs, but I run keyboard chat modes and in long rag chews that can run an hour+.
Like others I found the temp to run about 65 at worst and the fans keep the temp stable for me with a very slow rise if at all at that temp range.
Scott - Don't recall ever meeting you, but we are not far apart.
My LA-1K went back for warranty service two years ago.? While there it was upgraded with quieter T/R relay and fans (at a reasonable cost), but they mentioned cooling with the new fans was not quite as good.? They even returned my originals, should I wish to change them back.? My amp runs on 120V and will occasionally peak above 1000w on SSB phone.? I generally drive it with 45 watts, and get about 850w out.? On phone, it will warm (worse on higher frequencies), but even in contest mode will be OK, temperature wise.
But it's another story on FT-8, where prolonged use on 10 meters is limited to about 175-200 watts, with temp stabilizing above 70+ deg C.? Lower band FT8 will be OK at 250w, with stable temp operation in 60 deg range - although I normally don't run that high.? I'm also careful to never hit 80 degrees.? Other that what I consider to be excess temperature rise, the Amp seems to work fine.? Someday I should phone Palstar and see if they have other comments.
Without your additional plenum, were your FT8 temperatures similar to mine?? 10 meters has been super recently, and seems to be where my amp runs the hottest.
73 .... Fred,? W9KEY
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Hi Fred, My environment includes a Yaesu FTDX-101MP that I use with FT8 (the only mode I do).? I have an HF-Auto tuner and a 43ft vertical with dozens of radials.? I drive the amp with from 9 to 16 watts to get out about 330 watts.? I never go above that as my amp tends to go into bypass mode.? 330 watts is enough to do the world and I’m not complaining.? Going into bypass mode only happens on 10 and 12 meters.? Why? I don’t know.? It doesn’t happen on any other band.? My old Ameritron ALS1300X didn’t do that in the 8 years that I owned it.? It was an excellent, reliable amp but big and bulky (two boxes, not one) and service from MFJ was terrible.? The worst possible service imaginable.? So I sold it and got the la1k at the recommendation of the sales manager at HRO.? I’ve had it two years and it has needed service twice.? Once for an upgrade and once because I drove it too hard.? Each time Palstar had it back in around a week.? Excellent service, none better.? So why does it go into bypass mode on 10 and 12? No idea, I’m using the same antenna and tuner.? At 300 watts it doesn’t happen very often.? All in all, I’m very happy with it.? I do have the band cable on the amp and that seems to help.? I’m also using 220 volts.? Regarding temp: I always have my eye on the temp and when it reaches 64C I give it a break.? At 50C my fans kick in automatically and really work.? I’m on a very long time before the temp rises.? I hope this helps. Scott KC9WPS ?
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From: [email protected] [mailto:[email protected]] On Behalf Of Fred, W9KEY
Sent: Tuesday, January 31, 2023 2:56 PM
To: [email protected]
Subject: Re: [la1k] Digital modes and fast temperature rise ? Scott - Don't recall ever meeting you, but we are not far apart.
My LA-1K went back for warranty service two years ago.? While there it was upgraded with quieter T/R relay and fans (at a reasonable cost), but they mentioned cooling with the new fans was not quite as good.? They even returned my originals, should I wish to change them back.? My amp runs on 120V and will occasionally peak above 1000w on SSB phone.? I generally drive it with 45 watts, and get about 850w out.? On phone, it will warm (worse on higher frequencies), but even in contest mode will be OK, temperature wise.
But it's another story on FT-8, where prolonged use on 10 meters is limited to about 175-200 watts, with temp stabilizing above 70+ deg C.? Lower band FT8 will be OK at 250w, with stable temp operation in 60 deg range - although I normally don't run that high.? I'm also careful to never hit 80 degrees.? Other that what I consider to be excess temperature rise, the Amp seems to work fine.? Someday I should phone Palstar and see if they have other comments.
Without your additional plenum, were your FT8 temperatures similar to mine?? 10 meters has been super recently, and seems to be where my amp runs the hottest.
73 .... Fred,? W9KEY
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Scott,
Out of curiosity, what was the symptom or problem from the
over-drive?? Was there an error that pointed you in the direction
to say it won't operate until it is fixed??? Or did it just not
work, was sent in, and Palstar had to tell you what the problem
was?
Thanks,
David
On 2/1/2023 10:18 AM, Scott Sherer
wrote:
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because I drove it too hard
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Scott,
I used to have the problem of my amp going into bypass on digital modes all the time. Made it totally useless. However I changed the way I set up my radio and now the problem seems to be gone. A few years ago I read a recommendation that the levels for digital modes should be set as follows:? Set the radio for 100W (maximum for my radio) output, then use the audio level to drive it to get the output you really want. In this mode there is NO ALC going on at all, and I could easily get my FT-DX3000 to output a nice clean 30W or so. What I changed was to reverse this back to a way that seems to make more sense, and does work much better with the amp. I set the audio levels to just start bouncing the ALC meter, then adjust the power to get what I want. When I use the la-1k all I want is 5W which results in about 125W out. Now the problem is the temps keep climbing during longer transmissions. I probably would not have much trouble with FT8, but a 2-minute message using fldig sent the temp to 80!
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Hi, I blew one of the final transisters. J? Oops, lol Scott ?
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From: [email protected] [mailto:[email protected]] On Behalf Of David Campeau
Sent: Wednesday, February 1, 2023 11:51 AM
To: [email protected]
Subject: Re: [la1k] Digital modes and fast temperature rise? Scott, Out of curiosity, what was the symptom or problem from the over-drive?? Was there an error that pointed you in the direction to say it won't operate until it is fixed??? Or did it just not work, was sent in, and Palstar had to tell you what the problem was? Thanks, David On 2/1/2023 10:18 AM, Scott Sherer wrote: because I drove it too hard
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As I recall the continuous commercial service (CCS) rating for the LA-1K is about 225W output using 240VAC power line.? And the SWR needs to be as close to 1:1 as possible.? Depending on room temperature and humidity the LA-1K should run for weeks without overheating.? I typically run FT8 on any band without problems using 200-250 Watts output.?
KT3V
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My LA-1K will do the 200-250 watts FT8 described by KT3V, but only on lower frequency bands - might actually do more, haven't tried that much lately.
But on 10 & 12 meters, it will only do about 175 watts (200w for awhile as temp increases) before getting into the mid 70 deg C range.
Am running mine on 120 Vac and never run it any higher than upper 70 deg C (and even then, only rarely and for a short time).
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Fred, W9KEY