"the heatsink is cooler running at 200W output than at 125W output" This is typical on both VHF and HF amplifiers. Trying to turn down a commercial VHF or UHF repeater amplifier (or mobile radio pres
Search for a B&W PT2500. You may find something that way. Thanks 73 Jim W7RY No luck doing an internet search. Looking for a manual with schematic and parts list for a Viewstar PT2500A. Thank you. La
Ameritron most likely has them. Thanks 73 Jim W7RY Looking for the 160 meter wafer for an al80a ... anyone have or has anyone changed the contacts separately ... MIke N6JPR Send Amps mailing list sub
Looking for a pi network calculator that covers 6 meters. GM3SEK site just goes through 10 meters. Thanks 73 Jim W7RY _______________________________________________ Amps mailing list Amps@contesting
I found an on line one... http://people.physics.anu.edu.au/~dxt103/calculators/pi_tank.php Thanks 73 Jim W7RY Looking for a pi network calculator that covers 6 meters. GM3SEK site just goes through 1
I was reading QST this morning and I see that Paul Hewitt, WD7S is now a silent key. Anyone know what happened? I had not heard that he was sick. A great loss! 73 Jim W7RY Sent from Mail for Windows
Sounds like an intermittently shorted tube. Most likely the grid is shorting to the filament (cathode). Let us know. 73 Jim W7RY Sent from Mail for Windows 10 In standby at power on, reading the fron
Probably gas. Be careful. The tube will eventually short and take out parts in the amplifier. Most likely meters (if not PROPERLY protected, meaning not simply diodes across the meters) and other par
Ameritron MFJ has them. 73 Jim W7RY I have an Ameritron AL-80A, which unfortunately during the KH1/KH7Z expedition experienced bandswitch arcing when used on 17m in the 20m bandswitch position. (Oops
Sounds like Amp Supply. They were famous for that... Does it have a jones plug on the cables? 73 Jim W7RY I have a large brute 70 lb HV supply that came from an amateur QRO amplifier where what is in
I've done it both ways and either seems to work fine. There are 2 schools of thought on connecting the filament to the cathode to keep arcing from happening between the filament and the cathode. I've
Interesting article about Eimac and a broadcast transmitter manufacturer. http://www.thebdr.net/articles/prof/history/Fiasco.pdf If you like high power transmitters, this is a pretty good list to get
Anyone have a spare good TL-922 filament transformer? Let me know. Thanks and 73 Jim W7RY _______________________________________________ Amps mailing list Amps@contesting.com http://lists.contesting
A yc-156 is hardly a compact tube. Why does size matter? STAY AWAY from using toridal inductors for tank circuits. Unless its just for the L coil in a PI-L. Use good ole wire wound coil. #10 or 12 is
It is indeed a spline. Henry used spline. 73 Jim W7RY _______________________________________________ Amps mailing list Amps@contesting.com http://lists.contesting.com/mailman/listinfo/amps
Some various radio measurements here: http://www.w0qe.com/amplifier_timing.html Notice that the Ic706 and others actually unkey the relay (H-send line) before the tranciever stops sending RF. 73 Jim
Jim Instead of internet, don't you mean Ethernet? Just wondering. 73 Jim W7RY On 10/30/2018 9:48 AM, Jim Garland wrote: There has been considerable discussion on this group and elsewhere about the fo
Agreed! And the 30S1 is extremely stable. 73 Jim W7RY Can't any reason to drive a tetrode from catode ! REPLY: Stability. Cathode driven amps rarely need neutralizing. 73, Bill W6WRT ________________
Still looking for a good Kenwood TL-922 filament transformer. Thanks! Jim W7RY _______________________________________________ Amps mailing list Amps@contesting.com http://lists.contesting.com/mailma
The Drake L4B only need 2-4 diodes for bias. The less ZSAC the harder it is to drive. 73 Jim W7RY On 11/3/2018 12:25 PM, Jim Thomson wrote: Message: 2 Date: Fri, 2 Nov 2018 18:35:30 +0000 (UTC) From: