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Re: LA-1K overdrive warning
开云体育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
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Re: LA-1K overdrive warning
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? On Sat, Dec 24, 2022 at 07:39 <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.? |
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Re: LA-1K overdrive warning
开云体育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.? Richard Osborne? VE3OZW |
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Re: LA-1K overdrive warning
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:
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Re: LA-1K overdrive warning
开云体育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. ?Richard Osborne |
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Re: LA-1K overdrive warning
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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Re: LA-1K overdrive warning
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:
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Re: LA-1K overdrive warning
Dave Bates
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:
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Dave Bates |
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Re: LA-1K overdrive warning
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On Dec 24, 2022, at 8:39 AM, jloverti@... wrote:
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LA-1K overdrive warning
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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Re: Icom IC-746 Pro hook-up
Hi Richard... ? I have two of them and really like them.? Never thought I'd go to solid state amps, always had tubes since I never liked the behavior of FET amps.? This LDMOS implementation by Palstar is excellent.? The only thing to keep in mind, which you evidently already know, is not to over drive them.? LDMOS amps get dirty quickly when over-driven, but they're cleaner than FET amps when excited within their ratings. Good luck with it! Dennis On 12/5/2022 at 8:05 AM, "Richard Osborne" <ripcord203@...> wrote:
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Re: Icom IC-746 Pro hook-up
开云体育Thanks Dennis. I have received replies from a few hams with the same info. Good to know and also, that was the practice that I was following. I plan not to drive with anymore than 45 watts as that is giving me 1100w output. ?I am happy with that performance. Thanks to all that replied, you have been most helpful as I learn the ins and outs of this amplifier.Richard Osborne? VE3OZW |
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Re: Icom IC-746 Pro hook-up
I've never depended on (or used) ALC with this amplifier.? Much better just to limit the output of the exciter output to 40-50 watts.? Leaving the radio at full output and depending on ALC to limit output will always result in buckshot since there is a time delay between hitting the ALC threshold and the actual feedback which limits the radio's output.? It's not necessary to connect the ALC at all either through the band data cable or the stand-alone ALC connector.?
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Dennis N0SP On 12/4/2022 at 6:03 PM, "Jerry Webb" <jerrywebb45@...> wrote:
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Re: Icom IC-746 Pro hook-up
Not needed with SS LDMOS amps. On Sun, Dec 4, 2022, 19:05 Richard Osborne <ripcord203@...> wrote: Sorry to wake up and old thread.? Thank you for the detailed write up and explanation.? I recently purchased a Palstar LA-1K amplifier and absolutely love the operation of it.? I have installed the band data cable from the IC-7300 to the amplifier.? Direct keying is the way to go for sure with TX delay set to 15ms.? My inquiry is, I am not sure that there is ALC feedback between the amp and the rig.? I see that it is stated in the reply that ALC feedback is supported through the band data cable.? I see ALC feedback is supported from the IC-7300 through ACC2 pin 5, but I don't see ALC supported in the pinouts for the 9 pin radio interface.? Looking for confirmation as to whether the ALC cable is required between the radio and the amplifier. |
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Re: Icom IC-746 Pro hook-up
Sorry to wake up and old thread.? Thank you for the detailed write up and explanation.? I recently purchased a Palstar LA-1K amplifier and absolutely love the operation of it.? I have installed the band data cable from the IC-7300 to the amplifier.? Direct keying is the way to go for sure with TX delay set to 15ms.? My inquiry is, I am not sure that there is ALC feedback between the amp and the rig.? I see that it is stated in the reply that ALC feedback is supported through the band data cable.? I see ALC feedback is supported from the IC-7300 through ACC2 pin 5, but I don't see ALC supported in the pinouts for the 9 pin radio interface.? Looking for confirmation as to whether the ALC cable is required between the radio and the amplifier.
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Re: Band Data/Interface cable Elecraft K4 to LA1k
开云体育Winford makes nice breakout boards.? Remember NOT to connect anything to the PTT jack on the LA-1K if you use the keying pins in the DB9 jack. ?It's one or the other but not both. Also, if you're an avid CW operator, the LA-1K can be a full break-in amp with the ?addition of an electronic T/R switch such as the DXConnections QSK2500. ?The owner (K3HZP) hand-makes every unit and gives excellent support, especially in how to cable everything up. QSK keying is then done in the "DIRECT" mode rather than the "NORMAL" mode. 73, Kent K9ZTV On Nov 8, 2022, at 7:19 AM, W1SWL <artgumbus@...> wrote:
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Re: Band Data/Interface cable Elecraft K4 to LA1k
开云体育I made mine for my Yaesu FTDX101MP to the LA1K.Ordered a cable from Amazon and a modular connector from Amazon.. (hope this picture takes…) As you can see the Jienk cable has gold plated connectors which you fit into the ANBEST DB15 solder less serial 15 pin port. Is your connection 15 pin to 9 pin on your Elecraft? This cable fabrication was rather easy with these two parts. As a result, when my Yeasu changes bands the LA-1K also immediately changes bands as well PRIOR to the introduction Of any carrier or transmission. Art ?- W1SWL artgumbus@...
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Re: LA-1K Max feed-through power?
No issues at all passing 200 watts through the amp while it's off or in Standby.? I've done it many times. Dennis N0SP On 11/7/2022 at 9:32 PM, "Barry" <barplo@...> wrote:
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Re: LA-1K Max feed-through power?
James Barber
Thanks, Barry. I only use port 1 on the amp, so it’s easy.? The amp is powered off when I use the Yaesu, and there’s no PTT connection between them. The Yaesu and the other rigs all pass through an isolated multiport switch connected to the amp input. All the antenna switching is done out by the tower with a remote switch. If the amp will pass through the 200W from the Yaesu, I should be ok. 73, Jim N7CXI On Mon, Nov 7, 2022 at 8:35 PM Barry <barplo@...> wrote:
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Re: LA-1K Max feed-through power?
开云体育Further to my last. With the amp off it automatically thru puts connector 1. That is where you should put the FT5000 into. Connector 2 the amp needs to be on and that Connector selected on the amp. EG: The radio you want to use with the amp. ? From: la1k@groups.io <la1k@groups.io> On Behalf Of James Barber
Sent: November 6, 2022 10:40 AM To: la1k@groups.io Subject: [la1k] LA-1K Max feed-through power? ? Just bought a FTDX-5000MP, which I will not be using with the LA-1K. I do, however want to pass the 200 watts from the the Yaesu through the LA-1K on its way to the antennas. Any issues here? |
Thomas NE7X
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