Fan Power Supply PowerGenius XL and noise

Jean Drolet

Language problem I'm french I translate into English and it's not always good but here it is:

I find the amplifier noisy, I look at photos on the web and on facebook and from what I see the cooler seems to have fans in the front in the module located to the left of the amplifier.Besides, if I look at the back of the amplifier I see the cooler. I believe the power of the fans in cfm must be stronger because the whole is at the front and pushes to cross the path.

My question would it not have been more efficient and quieter to install weaker and quieter fans at the front and at the back of the amplifier. Those at the front pushing and those at the rear pulling.

4O3A Signature

Hello Jean, Thank you for your interest in making PGXL better. You have to know that PGXL, as any other LDMOS amplifier produce a lot of heat. We have invented and build in MEffA to increase efficiency and make it to be quiter. Keep MEffA enabled! MEffA works in CW and Digi. In SSB, to keep high IMD, amplifier has to operate closer to class A, with lower efficiency. In class A, as much output power you generate, about same portion of heat is generated too. So, removing 1k5 of heat from heatsink is noisy, and fans are blowing on about of maximum of speed. But, it will happen when duty cycle is very high. We have some room to improve and to make PGXL quiter and we will work on it on some of future firmware releases. Have on mind also the fact that other amplifiers are even louder. With PGXL we had on mind to have it away from operating desk, as it has dedicated App and is fully integrated in SmartSDR. Your proposal with front and back fans, in Push/Pull is widely used on broadcast transmitters, and produces a better air presure. Unfortunatelly it won't make a miracle and won't cool heatsink with lower CFM. Speed of fans for same CFM will remain the same. Only water cooling could really help. 73 Ranko

HCampbell WB4IVF

We have some room to improve and to make PGXL quiter and we will work on it on some of future firmware releases.

That is good news, Ranko.  There are situations where only a fraction of the PG XL’s capabilities are needed or desired.  It would be great if a “low power and noise” mode could be added, which would lower fan noise even below “Normal” mode while keeping fan speed at a high enough level to protect the amp.

Howard

Sergey KN7K

I am in the same situation with noise - very concerning when used in the room where is my station is and I do not have capability for remote placement or other room.

I did a project for a PGXL Noise mitigation and after testing it now for 3 month I would be willing to share.
I am not going to interrupt this thread but will post it in separate thread. 
Sergey, KN7K

Doug

I would like to comment with my experience as a new owner. I have my PGXL sitting on my operating desk and don't find on ssb it is a noise problem. It replaces a pair of 3-500z sitting at the same position . I don't understand the concern of noise because it is so easy to place this amp where ever. We have the ability unlike so many other amps to place this unit where needed for our tolerances to noise. With me on ssb I love it sitting on my desktop and watching the power flow !

Jean Drolet

I paid $ 11,500 canadian for the amplifier at this price I don't want to hide it in a room where I can't admire itnse

Tim VE6SH

I honestly do not find the noise as obtrusive as other solid state amps. The SPE was certainly louder and had a higher pitch. 90% of the time I wear headphones and it is barely noticeable.  Jean, I never did the conversion to $C. Too painful!

73

Tim VE6SH

DL4RCE

Please share

Jean Drolet

I love the PowerGenius post is to improve this fantastic device

Burch Akin

It can be a bit noisy but I don't understand all the complaints about the noise.  I guess I am used to my VHF/UHF full legal limit amps that have large blowers in them to keep the tubes cool.  PGXL much quieter.

Jean Drolet

I had a Tokyo Hy-power I compare to the same power 1kw and the PowerGenius is noisier just like my AL-82 is less noisy.

W5AP

I find the noise unacceptable inside the shack.  So I moved the PGXL outside to a "dog house" well ventilated and with a vent fan if needed.  The PGXL utility makes this operation easy and totally quiet. I'm located at near 9000 feet agl, so my air pressure is much less than at sea level, so my fans tend to run at a higher speed to compensate.

4O3A Signature

I agree that noise is lower comparing many other SS APMs, due to the MEffA and larger and better heatsink. But we have to remove heat and we have to have fans blowing.
I think that complains are more about expectations. Tube amps are quieter and most of users will expect about the same. 
Advantage of PGXL is in it's design and ability to change a lot of parameters with firmware. So, I can't promise a miracles, but I am sure that noise will be kept to a minimum with new firmware upgrades. For sure, in operate mode, while in receiving, PGXL can be much quieter.
I was personally focused on some more important technical factors in amplifier, and did not spent much time on cooling algorithm, but will do, together with Dave NX6D.

Thank you very much to all on comments. It is really very helpful to our team.

73
Ranko

Bob Needleman

Tim - curious which SPE Expert amp did you have that was louder than the PGXL? Someone else mentioned his SPE 2K was very quiet. 
Bob K3AC

DL4RCE

Hi all, noise is an option. It will never be as quiet as an Acom2000a or a Alpha87a. Does it have to be? There are always trade-offs. I changed because my tube amps dissapated (a lot) of heat even on standby! For some this matters, others may like a heater in the basement 73, Volker, DL4RCE

DL4RCE

A friend of mine modded a 1k3 v1. Now he is anxious to do high duty cycle modes

DL4RCE

Hi Ranko, thanks for your insights. Personally I do not think that water cooling is a good option for a (semi-)professional hobby. It maybe for commercial. I had a water cooled LDMOS and 1st it was not that silent since you need a radiator and secondly liquids in an amplifier is always a different story. Apart from that I always had problems with heat in high duty modes, but I guess that was design related

73, Volker, DL4RCE

4O3A Signature

Hi Volker,

I agree fully.
Water cooling is more complex and for HAM use it is not acceptable for few reasons, mainly due to the manner of use and maintenance.

73
Ranko

Tim VE6SH

Bob, it was a 1.3k. I found when it revved up the noise was much more intrusive than the XL. Could be just the pitch of fan.

Tim VE6SH

Bob Needleman

OK Tim - yes, I have heard from other SPE Expert owners that the fan has a bit of a high pitched whine that is annoying. Not sure if that's on all their models or just some.  I have owned (and sold) 2 SS amps in past 3 years -  an Ameritron 1306 and Acom 600, mainly because of the loud fan noise when I operate CW, my main mode. After about 6-7  mins or less (if it's already warmed up during a QSO), the fans would go into high speed and are pretty loud. I don't like wearing headphones and you can't remote the RF decks, so I didn't hold onto them. Guess you did the same with your SPE. GL with the PGXL.  73, Bob K3AC

KF4HR

Ranko - I fully understand cooling is a major priority for the PG-XL in the transmit mode, although I tend to listen considerably more than I transmit.  I would look forward to a change that would make fans quieter during the Operate/Receive mode.

Reference water cooling.  I'm curious if during the design stage of the PG-XL if water cooling was considered?  And do you foresee that as a possible future modification for the PG-XL?

Thanks again for a fantastic amplifier! 

Butch, KF4HR

4O3A Signature

Hi Butch, We will work on fan noise to reduce it as much as possible. Water cooling is one of options we are considering, but it is not easy as it looks like. Be sure we will come with some solutions in a future. Thank you very.much for trust and support. 73 Ranko

David Decoons, wo2x

I would have liked to see the design to be a bigger housing allowing more heatsink surface and use of larger (120 mm) fans. They would move a substantial amount of air at less perceived noise and lower pitch. i understand the target was to also make this amp portable for DXpeditions. Food for thought. Dave wo2x

Bill -VA3WTB

The way this amp is designed,there is no reason why it has to be in your shack. Place it anywhere away from your working area and forget it. I think that the amp being designed for only say 1% of the ham world, contesting. I'm not sure that was a good idea. I agree with Dave. Bigger box, large heat sink, and maybe a separate power supply. So it would appeal to most of the ham market.
In saying that, there are very few amps anywhere that can perform to the PGXL standards, many claim they do, but really they can't.

David Decoons, wo2x

Ranking, I am thinking of locating the amp in my garage in a server cabinet to minimize dust. Filters on air intake to cabinet and large exhaust fans at top of cabinet to dissipate heat. The only issue is my garage can exceed 90 F temperature in the summer. Winter never gets below freezing. Would this environment be suitable? Dave wo2x

4O3A Signature

Hi Dave, 90F is 32⁰C, which is fine 73

Bob Needleman

I think you meant to type: "90 F = 32. 0 C" Yes?
73,
Bob K3AC

David Decoons, wo2x

Ok. I just don’t want to have the amp unhappy 73 Dave wo2x

4O3A Signature

Sorry, 32⁰C

4O3A Signature

It just post different character. Yes, 32C, of course

Tim VE6SH

One of the key features for me is that the amp is an integrated unit in a relatively small form factor. A separate PSU would be a pain. Each to his own. 

Tim VE6SH