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On Wed, Dec 28, 2022 at 7:43 AM Terry Hursh < revhursh@...> wrote: On SSB phone I wouldn’t drive it with more than 40 watts.? On Dec 24, 2022, at 9:04 AM, Joe Loverti <jloverti@...> wrote:
? Dave, The 50 watts drive is not actually measured. It's where I set 'mic gain' on the 7300. It's interesting how you tune up. I'll have to try it that way. Thanks! On Sat, Dec 24, 2022 at 10:19 AM Dave Bates < Kf0xq1@...> wrote: I’d take it down to 35 or 40 watts drive.?
I use about 3 watts FM to tune the ?tuner, then ramp it up to 35. Then go back to SSB, then take the amp out of standby
On Sat, Dec 24, 2022 at 9:01 AM Kent Trimble, K9ZTV < k9ztv@...> wrote: Joe ...
50 watts drive as measured on which meter and in what mode?
Kent K9ZTV ?Hello! I'm new to the group and my first post. Just picked up a new LA-1K yesterday and I'm driving with an Icom 7300 with 50 watts. If I speak too close into the microphone the amp displays "Overdrive" and stops transmitting. Is this normal for the amp to be so sensitive to voice peaks?? I guess I just have to learn to pay more attention to how I speak into the microphone.?
Joe WW8X
Dave Bates
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I run drive my LA-1K with an ICOM IC-7610 at up to 45 watts max (most bands using SSB phone) and only once remember getting an overdrive trip-out warning.
Even with contest CQing, I typically set the drive between 40-45 watts, with resulting output at about 900 watts, with occasional peaks at 1000.
Amp is running on 120 Vac.
The only problem I have - my amp runs much too hot - into the high 70's C.
It will stabilize on SSB Phone per above, but testing on FT8 digital shows it will overheat at around 200 watts (depending on the band), and only 175 watts on 10 meters.? Been meaning to phone Palstar - perhaps there is something wrong with it?
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That’s a hot topic, Fred. I don’t do much other than SSB., and mine never reaches 50 C. I usually run about 35-40 watts drive, and easily do 900 out … Good luck with your issue…
I run drive my LA-1K with an ICOM IC-7610 at up to 45 watts max (most bands using SSB phone) and only once remember getting an overdrive trip-out warning.
Even with contest CQing, I typically set the drive between 40-45 watts, with resulting output at about 900 watts, with occasional peaks at 1000.
Amp is running on 120 Vac.
The only problem I have - my amp runs much too hot - into the high 70's C.
It will stabilize on SSB Phone per above, but testing on FT8 digital shows it will overheat at around 200 watts (depending on the band), and only 175 watts on 10 meters.? Been meaning to phone Palstar - perhaps there is something wrong with it?
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My opinion only, but anyone contemplating the purchase of a KW or higher amplifier should first purchase the services of a licensed electrician and get 240 VAC installed in the shack. Purchase of the amp itself comes second.
Most manufacturers do not recommend 120 VAC for any amp over 500 watts.
73,
Kent
K9ZTV
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On Dec 29, 2022, at 7:16 PM, Fred, W9KEY <fred.schwierske@...> wrote:
Amp is running on 120 Vac. The only problem I have - my amp runs much too hot - into the high 70's C.
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The temperature at certain outputs can vary a little from amp to amp.? Also, ambient conditions can determine the limits.? Long key-down operation at 200 watts will produce over 70C, that's not unusual.? It shouldn't get that warm on SSB unless you're using highly processed audio during very long transmissions.?? High ambient temperatures (like 80-degree room temperature) or high altitude operation will allow the temperature to increase more than expected.?? I live at 9,000 feet, and have to de-rate a little bit, but *never* approach a limit (or even 70 degrees) at SSB. ?? My amp is most efficient on 6 meters, upwards of 70%, and close to about 55% on HF frequencies. Dennis
On 12/29/2022 at 6:15 PM, "W9KEY Fred" <fred.schwierske@...> wrote: I run drive my LA-1K with an ICOM IC-7610 at up to 45 watts max (most bands using SSB phone) and only once remember getting an overdrive trip-out warning.
Even with contest CQing, I typically set the drive between 40-45 watts, with resulting output at about 900 watts, with occasional peaks at 1000.
Amp is running on 120 Vac.
The only problem I have - my amp runs much too hot - into the high 70's C.
It will stabilize on SSB Phone per above, but testing on FT8 digital shows it will overheat at around 200 watts (depending on the band), and only 175 watts on 10 meters.? Been meaning to phone Palstar - perhaps there is something wrong with it?
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I've had mine about a month and am running on 120V. Sometime in
the next couple of months I'll have an electrician run 240V.
My elmer has the exact la-1k copy on 240V and his fans
runs quiet, and doesn't get hot when on FT4/8.? My copy on 120V
does get a bit warm whilst on FT4/8, and the fans get very loud to
keep the heat down.? Just listening to mine, the FAN's appear to
have 3 stages whilst operating. and when it goes over 50C, the
fans should be pretty loud keeping the heat from building up.? As
a test, just a few minutes ago, did 10 CQ DX on 40 meters @1KW (45
Watts drive), along with 2 QSO's, and the temperature really
wasn't climbing higher than 54C. The fans appear to do the job,
but they are loud.?
Are your fans loud when the temperature rises?? Are the exhaust
vents clear of obstructions?
On 12/29/2022 9:53 PM, Kent Trimble,
K9ZTV wrote:
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My opinion only, but anyone contemplating the purchase of a KW or higher amplifier should first purchase the services of a licensed electrician and get 240 VAC installed in the shack. Purchase of the amp itself comes second.
Most manufacturers do not recommend 120 VAC for any amp over 500 watts.
73,
Kent
K9ZTV
On Dec 29, 2022, at 7:16 PM, Fred, W9KEY <fred.schwierske@...> wrote:
Amp is running on 120 Vac. The only problem I have - my amp runs much too hot - into the high 70's C.
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I've been using the LA-1K and HF-Auto behind a Yaesu FTdx101MP for almost 3 years now and have never had it kick out for any reason except once when I accidentally hit it with 200w drive. Ouch!?
My recommendations are: You should NEVER EVER drive the LA-1k with more than 60 watts. And you should NEVER consistently run the LA-1K at more than 300 watts output in FT4/8 modes. You should NEVER use "Mic Gain" to control RF output.?
It is your money but running the LA-1k at 1200 watts is nuts! It will damage the output transistors and shorten the amplifiers lifespan. I never run my LA-1K at more than 800 watts because to get any significant change in signal strength you'd have to go to 1600 watts. 1000 watts isn't going to make much difference. In my opinion, with a 1kw amplifier, anything over 800 is a waste of energy and unnecessary wear and tear on the amplifier finals.
I tune the HF-Auto with the FTdx101MP in RTTY mode and 10 watts output and the LA-1K in "Standby" mode. After the HF-Auto completes tuning, I switch the LA-1K to "Operate". Using this procedure, the drive power versus amplifier output power remains consistent across all bands. 40 watts drive results in 800 watts output. I believe that is due to the LA-1K always seeing a consistent SWR of 1.5:1 or less.
Another thing to watch for is intermittent problems in feedline, connectors, and baluns. As RF output power increases, these types of problems become more apparent. Baluns will overheat or burn out, connectors will arc, and feedline will become less efficient. The result is often intermittent HI SWR which will cause the LA-1K to "kick-out" due to HI SWR.??
Anyway, this is just my opinion and is based on my experience.?
73 kd4xr
Jerry
?
?
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On Sat, Dec 31, 2022 at 10:01 AM Jerry Leckness < kd4xr@...> wrote: I've been using the LA-1K and HF-Auto behind a Yaesu FTdx101MP for almost 3 years now and have never had it kick out for any reason except once when I accidentally hit it with 200w drive. Ouch!?
My recommendations are: You should NEVER EVER drive the LA-1k with more than 60 watts. And you should NEVER consistently run the LA-1K at more than 300 watts output in FT4/8 modes. You should NEVER use "Mic Gain" to control RF output.?
It is your money but running the LA-1k at 1200 watts is nuts! It will damage the output transistors and shorten the amplifiers lifespan. I never run my LA-1K at more than 800 watts because to get any significant change in signal strength you'd have to go to 1600 watts. 1000 watts isn't going to make much difference. In my opinion, with a 1kw amplifier, anything over 800 is a waste of energy and unnecessary wear and tear on the amplifier finals.
I tune the HF-Auto with the FTdx101MP in RTTY mode and 10 watts output and the LA-1K in "Standby" mode. After the HF-Auto completes tuning, I switch the LA-1K to "Operate". Using this procedure, the drive power versus amplifier output power remains consistent across all bands. 40 watts drive results in 800 watts output. I believe that is due to the LA-1K always seeing a consistent SWR of 1.5:1 or less.
Another thing to watch for is intermittent problems in feedline, connectors, and baluns. As RF output power increases, these types of problems become more apparent. Baluns will overheat or burn out, connectors will arc, and feedline will become less efficient. The result is often intermittent HI SWR which will cause the LA-1K to "kick-out" due to HI SWR.??
Anyway, this is just my opinion and is based on my experience.?
73 kd4xr
Jerry
?
?
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This may be old news to some, but I found an interesting video demonstrating Bob Sherwood’s advice on how to avoid “hot switching” a linear amplifier with a IC 7300 and 7610. He suggesting setting the TX delay in the setting menu. https://youtu.be/_n64XrSziDQ
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PEP is just too high start with 15watts drive then move up. Monitor output power as you modulate the peaks. Good luck. It’s a wonderful Amp. ?
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On Dec 24, 2022, at 10:19 AM, Dave Bates <Kf0xq1@...> wrote:
? I’d take it down to 35 or 40 watts drive.?
I use about 3 watts FM to tune the ?tuner, then ramp it up to 35. Then go back to SSB, then take the amp out of standby
On Sat, Dec 24, 2022 at 9:01 AM Kent Trimble, K9ZTV < k9ztv@...> wrote: Joe ...
50 watts drive as measured on which meter and in what mode?
Kent K9ZTV ?Hello! I'm new to the group and my first post. Just picked up a new LA-1K yesterday and I'm driving with an Icom 7300 with 50 watts. If I speak too close into the microphone the amp displays "Overdrive" and stops transmitting. Is this normal for the amp to be so sensitive to voice peaks?? I guess I just have to learn to pay more attention to how I speak into the microphone.?
Joe WW8X
-- Dave Bates
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I am using an ICOM IC-7610 with my LA-1K and HF-AUTO tuner. I have been having intermittent "OVERLOAD" issues. I can run the amp for several hours, then it starts "OVERLOADING" every time I speak into the microphone. When I AC power cycle the amp and back on, everything is back to working normal. Then a few minutes later, it goes into OVELOAD again. It does it mostly on SSB, however I have seen it happen also when first key on CW and RTTY.?
I called Palstar tech support and talked wtih Mark. He indicated ICOM IC-7300 and IC-7610 transceivers put out a HIGH PEP power spike on SSB and CW key-ups which exceeds the threshold value of the amplifier input station, causing the LA-1K to go into OVERLOAD.? He suggested using an ALC connection between the ICOM transceivers and the LA-1K, and playing with the ALC settings on both the ICOM transceivers and the LA-1K to find a value that stops the RF OVERLOAD peaks. He also suggested flattening out the transmitter audio using compression and mic gain levels, so no high RF peaks are being produced at key-up.
I have been trying Mark's recommendations and the jury is still out. Still having intermittent OVERLOAD issues, however not a frequent. I'm still trying to find that perfect sweet spot.?
Another local ham said maybe I am having floating RF in the shack causing the amp to go into OVERLOAD. I checked all my cables, connections, and I have everything connected to earth ground buss in the shack. No sure what else I can check there.
Anyone else have any input or recommendations?
Thomas NE7X...
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I agree with Bob's evaluation.? I used an Icom 7600 with my LA-1K? w/o and issues. My TS-890S has no issues.? I suspect that the SDR-function on the IC-7610, and it's "younger kin" IC-7300, might be the design problem.
I am using an ICOM IC-7610 with my LA-1K and HF-AUTO tuner. I have been having intermittent "OVERLOAD" issues. I can run the amp for several hours, then it starts "OVERLOADING" every time I speak into the microphone. When I AC power cycle the amp and back on, everything is back to working normal. Then a few minutes later, it goes into OVELOAD again. It does it mostly on SSB, however I have seen it happen also when first key on CW and RTTY.?
I called Palstar tech support and talked wtih Mark. He indicated ICOM IC-7300 and IC-7610 transceivers put out a HIGH PEP power spike on SSB and CW key-ups which exceeds the threshold value of the amplifier input station, causing the LA-1K to go into OVERLOAD.? He suggested using an ALC connection between the ICOM transceivers and the LA-1K, and playing with the ALC settings on both the ICOM transceivers and the LA-1K to find a value that stops the RF OVERLOAD peaks. He also suggested flattening out the transmitter audio using compression and mic gain levels, so no high RF peaks are being produced at key-up.
I have been trying Mark's recommendations and the jury is still out. Still having intermittent OVERLOAD issues, however not a frequent. I'm still trying to find that perfect sweet spot.?
Another local ham said maybe I am having floating RF in the shack causing the amp to go into OVERLOAD. I checked all my cables, connections, and I have everything connected to earth ground buss in the shack. No sure what else I can check there.
Anyone else have any input or recommendations?
Thomas NE7X...
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FYI; Never had an issue driving the LA-1K with a Yaesu FTDX101MP. Worked Great. Art W1SWL
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On Mar 8, 2023, at 2:07 PM, Jerry Webb <jerrywebb45@...> wrote:
I agree with Bob's evaluation.? I used an Icom 7600 with my LA-1K? w/o and issues. My TS-890S has no issues.? I suspect that the SDR-function on the IC-7610, and it's "younger kin" IC-7300, might be the design problem. I am using an ICOM IC-7610 with my LA-1K and HF-AUTO tuner. I have been having intermittent "OVERLOAD" issues. I can run the amp for several hours, then it starts "OVERLOADING" every time I speak into the microphone. When I AC power cycle the amp and back on, everything is back to working normal. Then a few minutes later, it goes into OVELOAD again. It does it mostly on SSB, however I have seen it happen also when first key on CW and RTTY.?
I called Palstar tech support and talked wtih Mark. He indicated ICOM IC-7300 and IC-7610 transceivers put out a HIGH PEP power spike on SSB and CW key-ups which exceeds the threshold value of the amplifier input station, causing the LA-1K to go into OVERLOAD.? He suggested using an ALC connection between the ICOM transceivers and the LA-1K, and playing with the ALC settings on both the ICOM transceivers and the LA-1K to find a value that stops the RF OVERLOAD peaks. He also suggested flattening out the transmitter audio using compression and mic gain levels, so no high RF peaks are being produced at key-up.
I have been trying Mark's recommendations and the jury is still out. Still having intermittent OVERLOAD issues, however not a frequent. I'm still trying to find that perfect sweet spot.?
Another local ham said maybe I am having floating RF in the shack causing the amp to go into OVERLOAD. I checked all my cables, connections, and I have everything connected to earth ground buss in the shack. No sure what else I can check there.
Anyone else have any input or recommendations?
Thomas NE7X...
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My 7610 works perfect with my La1k. I use the band change cable.
On 3/8/2023 1:43 PM, W1SWL wrote:
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FYI; Never had an issue driving the LA-1K with a
Yaesu FTDX101MP.
Worked Great.
Art W1SWL
I agree with Bob's evaluation.? I used an
Icom 7600 with my LA-1K? w/o and issues. My TS-890S has no
issues.? I suspect that the SDR-function on the IC-7610,
and it's "younger kin" IC-7300, might be the design
problem.
I am
using an ICOM IC-7610 with my LA-1K and HF-AUTO tuner. I
have been having intermittent "OVERLOAD" issues. I can
run the amp for several hours, then it starts
"OVERLOADING" every time I speak into the microphone.
When I AC power cycle the amp and back on, everything is
back to working normal. Then a few minutes later, it
goes into OVELOAD again. It does it mostly on SSB,
however I have seen it happen also when first key on CW
and RTTY.?
I called Palstar tech support and talked wtih Mark. He
indicated ICOM IC-7300 and IC-7610 transceivers put out
a HIGH PEP power spike on SSB and CW key-ups which
exceeds the threshold value of the amplifier input
station, causing the LA-1K to go into OVERLOAD.? He
suggested using an ALC connection between the ICOM
transceivers and the LA-1K, and playing with the ALC
settings on both the ICOM transceivers and the LA-1K to
find a value that stops the RF OVERLOAD peaks. He also
suggested flattening out the transmitter audio using
compression and mic gain levels, so no high RF peaks are
being produced at key-up.
I have been trying Mark's recommendations and the jury
is still out. Still having intermittent OVERLOAD issues,
however not a frequent. I'm still trying to find that
perfect sweet spot.?
Another local ham said maybe I am having floating RF in
the shack causing the amp to go into OVERLOAD. I checked
all my cables, connections, and I have everything
connected to earth ground buss in the shack. No sure
what else I can check there.
Anyone else have any input or recommendations?
Thomas NE7X...
|
I have driven my LA-1K with my IC-7300, my IC-7610, and my Kenwood TS-830S
– all without a band change cable.? I let the amplifier sense the band and
frequency.? Never any problems, not one.? Until recently I had two
LA-1K amps in parallel with the Palstar splitter/combiner handling those
chores.? I drove that configuration with both my 7300 and my 7610 – again
with no problems.? There is a photo of that configuration on my QRZ.com
page.?
?
George
W7GDK.?
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From: Jerry
Webb
Sent: Wednesday, March 8, 2023 12:07
Subject: Re: [la1k] LA-1K overdrive warning
?
I agree with Bob's evaluation.? I used an Icom 7600 with my
LA-1K? w/o and issues. My TS-890S has no issues.? I suspect that the
SDR-function on the IC-7610, and it's "younger kin" IC-7300, might be the design
problem.
?
On Wed, Mar 8, 2023, 13:54 Thomas NE7X
<thomasne7x@...> wrote:
I
am using an ICOM IC-7610 with my LA-1K and HF-AUTO tuner. I have been having
intermittent "OVERLOAD" issues. I can run the amp for several hours, then it
starts "OVERLOADING" every time I speak into the microphone. When I AC power
cycle the amp and back on, everything is back to working normal. Then a few
minutes later, it goes into OVELOAD again. It does it mostly on SSB, however I
have seen it happen also when first key on CW and RTTY.
I called
Palstar tech support and talked wtih Mark. He indicated ICOM IC-7300 and
IC-7610 transceivers put out a HIGH PEP power spike on SSB and CW key-ups
which exceeds the threshold value of the amplifier input station, causing the
LA-1K to go into OVERLOAD.? He suggested using an ALC connection between
the ICOM transceivers and the LA-1K, and playing with the ALC settings on both
the ICOM transceivers and the LA-1K to find a value that stops the RF OVERLOAD
peaks. He also suggested flattening out the transmitter audio using
compression and mic gain levels, so no high RF peaks are being produced at
key-up.
I have been trying Mark's recommendations and the jury is still
out. Still having intermittent OVERLOAD issues, however not a frequent. I'm
still trying to find that perfect sweet spot.
Another local ham said
maybe I am having floating RF in the shack causing the amp to go into
OVERLOAD. I checked all my cables, connections, and I have everything
connected to earth ground buss in the shack. No sure what else I can check
there.
Anyone else have any input or recommendations?
Thomas
NE7X...
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Hello Thomas, not an expert here but i use to have those 3 devices together in my shack.
What i can say is (some already told)
Those icom rigs are well known for alc overshoot.
So, use a good quality alc cable and calibrate alc level on the linear as stated in the manual. Most modern systems dont need it, but as told by the technician, use it.
When transmitting set the audio chain in the 7610, including comp and mic gain, eq, try Hand mic first, so never reach near the end of alc scale (red line), be conservative.
Super important: There is a semi hidden menu in the radio that is a tx gain compensation (i guess). Access via quick menu, ?Never touch that for nothing. My level was 47. How to unorthodoxy know its wrong or not: record a voice message, play it back transmitting and monitor with headphones. If there is a slight distortion, go back a notch. Record again, test.
Reflected power is a devil sometimes. If using a balanced antena fed with coax, put an adequate choke at the feed point. If using ladder line, choke the transition to coax outside the shack.
Use good ground strips, bus and conductor to rods.
Maybe you already know all of this info but those are my 5 cents :)
PS: If able try to put a PEP meter in line like a smorf or a lp100a, or a dc powered bird 43.
While in RTTY set your pep till reach 1000 watts then go SSB. Dont try to get 1kw using ssb and a wattmeter. Thats ?a SS amp killer combo.
Let us know how it went please.
73,
Philip
CE4PS
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UPDATE:
This intermittent OVERLOAD issue was driving me crazy. However, I think I may have resolved the issue. Time will tell.
When it was on SSB I was getting RF clipping reports on my transmit audio. So, I decided to redo all my interconnecting cables between my IC7610, LA-IK, and HF-AUTO. I also changed all the cable lengths, some shorter and some longer. It's been 48 hours now and my LA-1K has not tripped into OVERLOAD once. Keeping my fingers crossed, maybe this resolved the issue.
Thomas NE7X...
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Fred, W9KEY
Thomas NE7X
Philip Smith