I have gathered from all the info that I have read on amps using the GS-35b that a healthy air flow is necessary to keep these tubes happy. Unfortunately, the 100 CFM squirrel cage blower that is re
ORIGINAL MESSAGE: (may be snipped) REPLY: 100 CFM is a lot of air. You might try slowing the blower down while monitoring the tube seal temperature at full output. The critical points on the tube are
I don't know what the "recommended" blower is, but bear in mind slow speed blowers can be much less noisy than high speed ones. They tend to be physically larger, however. On some prior amps I used h
Some builders water cool these tubes. It that an option? I don't know what the "recommended" blower is, but bear in mind slow peed blowers can be much less noisy than high speed ones. They tend o be
Yes, that Dayton blower is a good one to use, however, it is still quite loud even with the slower speed. Of course, you can reduce the fan speed on receive, but when transmitting, the noise is obje
Yes, water cooling would be really neat! I understand that the GS-35a version of the tube has a water-jacket, but you never see those for sale. I have seen some home brew examples for other tubes,
Jack, many homebrewers hang the blower off the rear panel to allow pressurizing the entire amplifier cabinet. That certainly gets the cooling job done but with maximum blower noise. Another approach
As a helicopter and airplane pilot, I love fan noise. It is a reassuring quality. Panic sets in when things get quiet. When running qrp, I always want to add a fan somewhere just so people know I am
Dont overlook a good muffin fan either. The EBM Papst 4600N was used in later production LK-800's using the 3 3CPX800A7's at about 3100V. That is a lot of fin area and back pressure. They are also fi
Dont overlook a good muffin fan either. The EBM Papst 4600N was used in later production LK-800's using the 3 3CPX800A7's at about 3100V. That is a lot of fin area and back pressure. I ran a quad of
I have a muffin fan to cool my pair of GI-7bT 160-meter amplifier. The tubes definitely run cool. The noise level is relatively low. Glen, K9STH Website: http://k9sth.com I ran a quad of 4cx250b
On 2/20/2014 9:51 AM, Jack C. Shutt wrote: Yes, that Dayton blower is a good one to use, however, it is still quite loud even with the slower speed. Of course, you can reduce the fan speed on receive
Another approach is to locate the blower inside the amplifier and only pressurize the tube from the bottom. Ameritron AL1200,1500 and maybe others work that way and have much lower blower noise. The
Low audio noise means a big blower running slowly. There was an old professional tx with 16 4CX250B in a distributed amplifier (cabinet 7 foot high, 2 feet wide and 3 feet deep!) that had an external
I believe that the numerous models of 8874 Alphas did not come from the factory with that fan. The back panel was punched for ventilation and was a convenient place to mount one. My 76PA 3 holer came
A possible blower you could consider is the EBM Papst G1G108-AB17-02, this is capable of over 100 CFM at low pressures and could well be adequate if you are not going to push things too hard. The goo
Ive already mentioned the EBM Papst 4600N as an adequate substitute earlier in this thread. Ive used them and altho havent measured backpressure the spec sheet curve inticates it handles backpressure
Is it the blower that is noisy, or the air that is noisy? On my 4CX-1500B/FU728F the noise fron the exhaust is far louder than the fan and particularly in "high blower" A comment on "off axis air flo
On 2/20/2014 9:59 AM, Jack C. Shutt wrote: Yes, water cooling would be really neat! I understand that the GS-35a version of the tube has a water-jacket, but you never see those for sale. I have seen