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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
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Joe ...
50 watts drive as measured on which meter and in what mode?
Kent K9ZTV
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On Dec 24, 2022, at 8:39 AM, jloverti@... wrote:
?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
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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
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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 have the same issue with my IC-7610 and LA-1K.? For SSB I need to set the mic gain and RF output to around 35-40 watts PEP or the LA-1K will trip into OVERLOAD. This only gives me around 650-700 watts output on the HF-AUTO tuner display. However, on RTTY, FM, CW and AM this is not an issue, I get a full 1100+ watts carrier output with 70-80 watts drive. This is the same with or without ALC connected.?
Thomas NE7X...
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Wow! ?On my 7300, I have mic gain set to 15% using a Heil Proset iC headset, and 45% drive to get greater than 1200 watts output from the LA-1K (240volts.) ?I never have to go higher than 45% on any band to get over 1000 watts. ?
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There may be a difference in output between FM mode and SSB.? It could be that when you set, say 45 watts, in FM, that SSB mode may be giving you more than 45 watts.? Also, all ALC circuits have some overshoot where there are some number of milliseconds before the ALC responds to cut the power to the regulated amount.? It's during that short interval where high power it sent causing the amp to fault.? I had this problem with one radio and I fixed it with a 9v battery and 10-turn pot putting a fixed negative ALC voltage on the radio's ALC input which hard-limited it to the desired output.? There is no over-shoot in that situation.? Some radios have better power regulation than other's.? I always liked Yaesu's speech processors since they hard-limited the output.? I'd engage the processor (with minimal compression), reduce the drive to the desired amount and since it was an RF processor (NOT an audio processor a-la older Kenwood), it would limit with no overshoot.? Having a GOOD peak-reading watt meter would let you know if you have momentary overshoot. Dennis
On 12/24/2022 at 10:27 AM, "Richard Osborne" <ripcord203@...> wrote: Wow! ?On my 7300, I have mic gain set to 15% using a Heil Proset iC headset, and 45% drive to get greater than 1200 watts output from the LA-1K (240volts.) ?I never have to go higher than 45% on any band to get over 1000 watts. ?
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I understand all of that. Simply a reply to the previous post on the thread where they required excessive drive power. Maybe I didn’t read their post correctly. ? I am using a Telepost LP-100A to measure output power. They are a good quality meter.?
I am sure there is some overshoot as the 7300 is notorious for overshoot. ?Anyway, I guess I didn’t explain properly and for that I apologize as I caused you some extra typing.?
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Depends on the band for me. I find 15m i have to really back off my drive to about 30 watts to get 900 out. Seems most efficient on 15m for me. I find if the amp goes over 1000kw output, it will go into bypass with a highswr fault even though the swr is fine, i think that is just how its designed.?
Sounds normal to me.?
Barry VE6UM?
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
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Joe ...
The LA-1k (like all amps) is just an additional power amplifier
added to a transceiver's power amplifier.? All it wants is RF
drive and that drive is controlled by the RF output control of
the transceiver, not its mic gain or compression level.
Initially (with the LA-1K OFF or in STBY), these two transceiver
parameters (mic gain and compression level) are set according to
the transceiver's manual as indicated on the transceiver's meter
and left there unless one changes microphones or goes
through a second puberty.
Assuming whatever ATU being used has done its matching, the
LA-1K is put in OPERATE, the transceiver keyed in either CW or
RTTY, and the transceiver's RF OUTPUT control increased until
the LA-1K is showing 1000 watts on its meter (but in no case
should transceiver drive exceed ~50 watts on a peak-reading
wattmeter).? Then switch to whatever mode you want.
Mic gain and compression should not be used to adjust
the LA-1K's output, nor should the LA-1K's output be set in SSB mode.
In SSB, output
power will vary with modulation.
Others talk about running their LA-1Ks at 1200 watts.? It's your amp and your money, but the LA-1K is rated at 1000
watts.?
73,
Kent
K9ZTV
On 12/24/2022 10:04 AM, Joe Loverti
wrote:
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The 50 watts drive is not actually measured. It's where I
set 'mic gain' on the 7300.
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Kent,
Could these amps have the old LA-1K software that does not have the revised SWR plus Reflected Power check?
73
.... Bill K3HZP
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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:
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Kent,
Could these amps have the old LA-1K software that does not have the revised SWR plus Reflected Power check?
73
.... Bill K3HZP
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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
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Thanks. This amp was picked-up at the factory this past Wednesday . It was just built and is version 1.085'
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Thanks. I don't mess with the mic gain either. I'm keeping the RF power under 50%
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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.
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On SSB phone I wouldn’t drive it with more than 40 watts.?
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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
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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
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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
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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
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Thomas NE7X
Bill K3HZP
Tony VA7TF, VE7ACF
Bob WB8CAC