Flex 6700 ALC Connect for PA

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My Flex 6700 works with PA Hilberling HPA 8000B. It is connected by a USB cable with FTDI by RS323 Mam CAT. I connected RCA ALC Flex 6700 with PA, I inserted Hardware ALC in SmartSdr but ALC does not work. Do I have to reduce the power out in Flex every time so that PA will not be overdriven ?.Slawomir
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Slawomir

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Posted 7 months ago

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Bill -VA3WTB

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Most people do not use ALC on the Flex,,you could just set the output power to what you want and forget about it.
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KC2QMA_John

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I see people say all the time you don't need to use the ALC connection on the flex or on peoples amplifiers. My question why do manufactures still put ALC on new radios and amps if no one uses them?
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Ria - N2RJ, Elmer

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On other radios it’s still used, and dare I say misused. SPE uses it to control drive power for example. Eventually flex will be using ethernet to set drive on the PG XL. So the alc negative voltage will be out of date.

The thing about ALC is that it’s not really necessary if you set your drive levels properly. I’ve used it once or twice with icom radios and ameritron and alpha amps and just never bothered with it again.
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Neal - K3NC, Elmer

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After spending 30 hours with my butt in chair during a contest, I did not want to remember maximum drive settings per band in order to get all the watts out of the legal limit amp I purchased just for that reason. I fried a PW1 3 times doing that so decided that a solid state amp (at least at that time) was not my best choice. I went with the Acom 2000A and it has been a tremendous asset. Protects itself quickly from a stupid op (me!). If ALC is implemented and working, I will use it in addition to Acom's built-in protection.
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Ria - N2RJ, Elmer

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Like I said - ALC is there but I don’t use it and I find it to be a band aid for proper drive settings. But it’s there if you want to use it. Also “getting all the watts” is kind of like “all knobs to the right” and I do like headroom which is why I don’t own a 1.3kw amp anymore and now own a 2kw one.
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KC2QMA_John

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That’s why I love my AL-1200, You cant really overdrive the amp with a Flex since it takes about 140/150W to drive the amp into IMD. The only down side with the AL-1200 is it manual tune.
(Edited)
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Ria - N2RJ, Elmer

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There is an option for hardware ALC in SmartSDR. Make sure it is enabled. I am not sure how well it works with solid state amps though. It didn't work well with my SPE 1.3K-FA, so I used their drive adjustment feature. 


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Neal - K3NC, Elmer

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I do not know why I thought this hadn't been implemented yet, must be my medications! How long has it been out there?
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Ria - N2RJ, Elmer

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The hardware ALC disable/enable? Not sure. It’s there in 2.0.19.
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Slawomir

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I have not used the ALC connection so far. But I do not want to constantly remember to reduce the power in Flex so that the protection against high power does not turn off the amplifier.
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Ria - N2RJ, Elmer

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Then lower your drive sufficiently so this doesn’t happen. If you run 1kw people won’t notice if you run 950. But if your hardware ALC is enabled it should work.
(Edited)
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Slawomir

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I can not provide more than 50 watts for the PA Hilberling HPA 8000B, so I have to remember not to exceed this input level. When is ALC only a dummy?
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Ria - N2RJ, Elmer

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You can also set the max power to 50w in the same s
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KY6LA - Howard, Elmer

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I use DDUTIL to automatically set my drive levels for each band.

I gave up using ALC years ago because of the inherent distortion that it caused.
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Marc Lalonde

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sorry to resurrect a old post   ,but need some clarification 

until now my HF amp was only use and connected into 6m beam
while waiting for new radio i work on my setup and add extra antenna HF Jack  for "HF" antenna

now is my problem AMP need 25W of drive for full power on 6M  ,but only 13W on 160M
so forgot to set back power and you overdrive or blow the LDMOS quite sensitive on input

first option is change Attenuators for 100W of drive  , i really not what this , WLY make 100W signal to later wast it into heat for drop it  to 2.5W  for drive the LDMOS  ??

second option is ALC  ,every one seem to said to not use it  ,but think it may avoid overdrive and let operator see ALC meter  for  fix the drive level ?  

Third is software ACL Via Telnet and Flex API  or CAT  ,not like that option because possible software glitch 


  
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Tim - W4TME, Customer Experience Manager

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You can use ALC, but the best option is to create a global profile and set the power levels for that band.