Re: LA-1K overdrive warning
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
?
?
|
Hi Craig - the 240V cable is?14AWG, NEMA 6-15P to C19 
|
Re: LA-1K overdrive warning
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:
toggle quoted message
Show quoted text
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.
|
Hi
I picked up an amp 2nd hand and it didn’t come with the 240v power lead/cable - anyone know where I could get one (I’ve emailed Palstar but maybe you know somewhere I can get one faster) and could someone please tell me what the power outlet connector type is so I can make sure I get my electrician to wire up the correct outlet. Thanks!
|
Re: LA-1K overdrive warning
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?
|
Re: LA-1K overdrive warning
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
toggle quoted message
Show quoted text
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.
|
Re: LA-1K overdrive warning
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?
|
Re: LA-1K overdrive warning
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?
|
Re: LA-1K overdrive warning
toggle quoted message
Show quoted text
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
|
Re: LA-1K overdrive warning
I ran my IC-7300 with the LA-1k for several months.? The overdrive was a constant pain.? Unless I set the 7300 for 38 watts, the issue was always there.? Even at 38, occasionally the 7300’s crappy ALC would let a brief spike through and the LA-1k would dump.? I duplicated these results with three different 7300s.? As much as I loved the IC-7300, I replaced it with a FT-710.? I can leave the radio set at 44 watts and get 1000 out with no overdrive glitches.? Sorry, I can’t provide any easier remedy.
?
73
Bob? WB8CAC
|
Re: LA-1K overdrive warning
I ran my IC-7300 with the LA-1k for several months.? The overdrive was a constant pain.? Unless I set the 7300 for 38 watts, the issue was always there.? Even at 38, occasionally the 7300’s crappy ALC would let a brief spike through and the LA-1k would dump.? I duplicated these results with three different 7300s.? As much as I loved the IC-7300, I replaced it with a FT-710.? I can leave the radio set at 44 watts and get 1000 out with no overdrive glitches.? Sorry, I can’t provide any easier remedy. ? 73 Bob? WB8CAC
|
Re: LA-1K overdrive warning
These solid state amps do not need too much drive.
Starr with 10 watts drive and then increase the drive. You will be surprised.
Regards,
Tony
VA7TF? VE7ACF
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
|
Re: LA-1K overdrive warning
On SSB phone I wouldn’t drive it with more than 40 watts.?
toggle quoted message
Show quoted text
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
|
Joe ...
Think that was a typo.? It would be version 108S.
But typo or not, it confirms that the version in new builds is
the same as the current version available on their website.
Enjoy your new amp!
73,
Kent
K9ZTV
On 12/24/2022 5:22 PM, Joe Loverti
wrote:
toggle quoted message
Show quoted text
Thanks. This amp was picked-up at the factory this past Wednesday
. It was just built and is version 1.085'
_._,_._,_
|
Re: LA-1K overdrive warning
Thanks Kent. The ATU is an HF-Auto. I get a good match using RTTY on low power with the amp in STBY. With the amp in line, I don't exceed its recommended rating.
|
Re: LA-1K overdrive warning
Thanks. I don't mess with the mic gain either. I'm keeping the RF power under 50%
|
Re: LA-1K overdrive warning
Thanks. This amp was picked-up at the factory this past Wednesday . It was just built and is version 1.085'
|
Re: LA-1K overdrive warning
Mike gain should be a constant setting. Do you have an RF power adjustment ?? I never touch the mic gain once I initially set it?up ….
On Sat, Dec 24, 2022 at 10:04 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
|
Re: LA-1K overdrive warning
Hi Bill and Merry Christmas!
Who knows.? So many variables:? CMC, poor antenna installation,
bad coax, all the usual suspects that don't manifest themselves
at lower power.
My concerns involved one guy saying he pumped 80 watts of drive
into his, and another using mic gain to set exciter drive.
Hope all is well.? Your QSK-2500 still working like a champ
between my FT-991A and LA-1K.? Love it.
Stay warm, stay safe.
CU on SKN?
73,
Kent
K9ZTV
On 12/24/2022 3:14 PM, Bill K3HZP
wrote:
toggle quoted message
Show quoted text
Kent,
Could these amps have the old LA-1K software that does not have the revised SWR plus Reflected Power check?
73
.... Bill K3HZP
|
Re: LA-1K overdrive warning
Kent,
Could these amps have the old LA-1K software that does not have the revised SWR plus Reflected Power check?
73
.... Bill K3HZP
|
Craig S
Fred, W9KEY
Bob WB8CAC
Tony VA7TF, VE7ACF
Bill K3HZP