<snip>..<snip> Hi Peter, If you are concerned with the high failure rate of silicon/IGBT's, you could also construct a real heavy switcher with...tube's....-:) gl, Carel. ___________________________
Fern, I have used a "butchered" air inlet from a cooker hood (at least I think that is how it is called :-)) with an opto-coupler in my gs35 amp. See http://www.xs4all.nl/~kvgog/projects/gs35.html Ma
Not exactly HF, but it might provide some other ideas. For my VHF amp I am using for years the (fault)control (incl. TX/RX sequence) as described at: http://www.pc5m.com/projects/gs35.html Provided i
Hi, Anyone could point me to some resources describing the best way to mount RF powermodules for UHF use (like the Toshiba RA13H4047). ? Did googled around a bit (found a Motorola patent, 5546275) an
Hi, Another aproach I have seen is to signal a glitch (or any over current situation) by measuring the HV-current and fire a string of thyristors. Those thyristors are accross the HV ! and shorting b
Hi, Al of a sudden I experience with my gs35b triode amplifier the condition of High (200mA) grid current and NO kathode current when applying only PTT (do drive). Also the powersupply indicates the
Hi Steve, I suppose you use a low power zener and 2n3055: If you just connect via a relay of single pole switch the lower valued zener in parallel with the higher voltage zener all would be fine. Gl,
Hi Marv, Do you remember which kind/type of rectifier diodes you have been using ? Did do some research and found some ultra-fast diode's (trr < 30ns) with decent reverse voltage (600V), but would be
Ulf, If you use a small valued resistor for the sake of measuring grid current in a triode grounded grid configuration and as such make sure the voltage drop over that resistor is smaller as 0.5V und
I think a small linear or even a switch mode power supply (however, be aware of the switching freq. noise) for the heather will do the job easily. No fiddling around with variacs, perfect control and
Hi Cecil, 1. Use an (external) sequencer which act upon PTT assertion (CW and/or SSB) and controls your rig and amplifier accordingly 2. Use some delay between assertion of CW PTT and first dit/dot t
Hi, I would like to get the opinion of this group on constructing a homemade variable 500 pF/1nF capacitor for my new 160mtrs amp. To get sizes down I am considering using 1mm (40 mill) thick teflon
First of all, thanks a lot for all contributions so far ! Seems to be a fun project to take on : - ) One thing I did in the meantime was to calculate/check the field strength in the airgaps which wil
Did a small experiment: See www.pc5m.com/skineffect1.jpg - Groundplane with BNC connector and wire on top to ground - Connect sweep RF generator and spectrumanalzer parallel at BNC - At half wave res
Hi Larry, Could you repeat your experiment with a subtle change: don't drill a hole through the discs but solder/connect the wire on both sides ? I think it will change your results. Carel. --Origina
That's a pitty Larry :-) Reason for asking is that (maybe you have seen my post) I did basically the same experiment. However, with opposite result! Only difference I can see is that I didn't had a t
Don't know how big that capacitance would be, but expect very small (although that statement doesn't mean anything to the end result...) What I did do (to see if the capacitance from the bottom part
Correction: not 0.1 inch but 1 inch... _______________________________________________ Amps mailing list Amps@contesting.com http://lists.contesting.com/mailman/listinfo/amps
Bill, You are right ! Changed my setup and to summarize the results: www.pc5m.com/skineffect2.jpg ). Fres = 260 MHz www.pc5m.com/skineffect1.jpg) . Fres = 260 MHz I suppose I can only conclude that t
Hi, as one of the "experimenters" with solid metal disks and taken the conclusion (based on the latest experiment) that RF current must go through the material I have reasonable doubt that my conclus