Jim, Tap water has long been used as a coolant in high-power loads, like the Altronic Omegaline models. In college, I used a 25KW Omegaline water-cooled load with a Harris FM-25K FM broadcast transmi
Glycol is not a requirement with the Altronic Omegaline. It works with running tap water from a common faucet to a drain or sink. It's that simple. Paul, W9AC _______________________________________
True as long as the characteristic Z of the additional line remains constant. In the literature, this footnote needs to be added to the general statement above. It's been repeated over-and-over agai
Quick story: Back in college, I rebuilt the PA cavity of an RCA 5KW FM transmitter. The owner of the station was an ex-CBS Radio engineer. When I completed the hardware assembly, he asked what I use
John, I believe I first brought that up. You can Google my callsign with some key words and I'm sure you'll see my comments in the archives. In a nutshell, getting the AC wiring correct on the Alpha
Temperature and working voltage are the major drivers affecting life span. Roughly, for every 10-degree C reduction in rated working temperature near the maximum working operating voltage, life doubl
!972. 9th grade, and just finished assembling an HW-101 and HP-23 power supply. I wired the filter 'lytics in backwards and after about ten seconds, the caps split, and white borax dust was everywhe
In the ACOM 2000A, three-state bias is used. -124V on standby, -75V during plate idling when the PTT line is pulled low, and -52V when input RF is sensed. When using VOX, the amp is quickly transiti
Don, Condenser Products in Brooksville, FL can make oil caps in most any size you want. Ask for Gene. Several AMPS members, myself included, recently completed a group buy of oil caps for our Alpha 7
I believe the speaker for that session was Bill Whitaker, a well-respected engineer. Probably Jim, K9YC knows him on a first-name basis. The vacuum tube v. solid-state debate has been raging on since
Or, old ARRL Handbooks and Antenna Books from the 1930-'50s. Nor early Frank Jones Handbooks. There is important, detailed material covered in those early editions that is not adequately covered tod
dissipation in such a small box. I have the 1K version of the SPE amp. Nice, compact and reliable design. If the League's QST product review is to believed, IMD performance is excellent for a solid-
Joe, Do you detect obvious output power change with changes in PA temperature? I see about a 10% reduction with the 1K, approaching 15% when the PA deck starts getting really heat stressed. While ope
Jim, Based on my experience, I agree with your comments above. First, the solid-state amps I've used are not very power-stable with PA deck temperature. In the broadcast industry, output power must
It's possible for the ALC mechanism in our amps to manage that much to the same degree as commercial automatic power control. Its just a matter of applying the right algorithim to the ALC bus. I sus
Or...vapor-phase cooling of a heatsink? I could see the heatsink resting in a filled boiler without the need for a pump, using only convection currents caused by water heating and a small whisper fa
temperatures with vapor phase cooling. However, a small radiator and closed water system would work very well. With a suitable pump the radiator/reservoir/fan could be located outside or in another
Very little water flow is needed from a cool source. Back in the '80s, I managed an FM site atop what is now the Wells Fargo Building in downtown Jacksonville. An Altronic Omegaline water-cooled loa
Dick Frey, K4XU gave me permission to post his interesting insight (see below). Dick is an engineer for a major semiconductor manufacturer. Probably the chart won't make it through the mail list. Tho
Pete, It would be great if Dick, K4XU contributed to the list on a regular basis. Now there's a guy who can add some value to the discussions here. I believe he was part of some amp designs for Alpha