Anyone know of a working 8873 available anywhere? Resurrecting an SB-230 for a local ARES/RACES group and haven't been able to find one... Thanks. -- Jeff WN3A _______________________________________
In solid state broadcast transmitters, there is always APC (automatic power control). The exciter or IPA power output is varied dynamically, usually under microprocessor control, to keep the final T
Ahhh...now there's the rub... Liquid cooling has become quite mainstream. Heck, even liquid cooling overclocked PC CPU's and GPU's isn't uncommon. I can walk into the local MicroCenter and buy every
I've had a Palstar HF-Auto for about six months now, and so far, no arcin' or sparkin' at the legal limit into some fairly ugly loads, particularly on 75/80m where I have an inverted vee cut for the
In contrast, I was running 24/7 trying to keep three of them on the air... _______________________________________________ Amps mailing list Amps@contesting.com http://lists.contesting.com/mailman/l
That sure sounds Maxwellian to me (Walt, not James Clerk :-) -- Jeff WN3A _______________________________________________ Amps mailing list Amps@contesting.com http://lists.contesting.com/mailman/lis
I usually go by taste. Seriously, the most-basic test is that PCB oils are heavier than water, while mineral oil is lighter than water. A couple of drops of of the subject oil in a cup of water woul
Minor correction - you used diameter of the puck instead of the radius when calculating the area. C = 2.1 * 0.2248 * (1.5/2)^2 * pi / 0.75 = 1.11 pF Xc = 1593 I = 10607/1593 = 6.66 Arms -- Jeff WN3A
There was an article published (Handbook? QST? QEX?) for homebrewing a 2m kilowatt-class amp using the 3CX1200Z7/YU-181. I'm wondering how close the Henry design is to that. The Z7 is a nice tube fo
Yes, at VHF and above I use DC's and HP power meters and sensors (E4418/4419) to check the accuracy of other meters. HP (er, Keysight) has spreadsheets for calculating error/uncertainty given all of
John, Were you on the design team for the BE transmitters of that era that started the "folded half-wave" cavity design, eliminating plate blockers? If so, kudos to you. I've had the pleasure (mostl
I agree. In liquid-cooled broadcast transmitters (both tube and solid-state), the thermal transfer fluid is typically a 50/50 mix of distilled water and Dowtherm SR-1. SR-1 is ethylene glycol with c
No, you have it backwards. -- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus _______________________________________________ Amps mailing list A
Which is why if there is ever a chance that you might need both 120 and 240 in the same piece of equipment, run a 4-wire branch circuit (two hots, neutral, EGC) and use a 4-wire receptacle like a L1
As I said, it is applicable to existing installations where the branch circuit doesn't have a separate EGC, but the appliance presents both 240V line-to-line and 120V line-to-neutral loads. It's not
Most definitely - just about any multi-carrier system. But let's separate "modulation modes" from the requirement that an *amplifier* be ideally linear. In the non-amateur world (including broadcast
Harris DX50 probably? But if it were a DX50, the design was such that the modules weren't operated separately for RF and modulation. The amplifier modules all ran at RF, and they were individually s
I think the above needs additional clarification. If there is a 2:1 load mismatch, and if the characteristic impedance (Z0) of the transmission line is the same as the Z the transmitter is designed
OIB's are quite handy. I have an OIB3 and always wanted an OIB2. You can also do high-power swept Z measurements using a conventional vector network analyzer (i.e. one without an integral test set)
5/8-24 -- Jeff WN3A -- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus _______________________________________________ Amps mailing list Amps@con