A secondary issue on the filament transformer grounding/ungrounding: When the transformer secondary is floating, it then becomes important that the transformer primary to secondary breakdown voltage
Hi Will, I am interested in info on the gas discharge devices. Seems these might be more precisely set than a gap device what with air/altitude effects. 73/k5gw ______________________________________
Hi Gerald Eimac recommends the Siemens B1-C145 for the 3CPX5000. I believe Phil, K5PC, has looked for this and found it obsolete, not sure what he crossed it to. I'm using a Bourns 2035-09-B, (90v) f
Epcos (Siemens) and Semitron make them, among others. For example, a search for GAS DISCHARGE TUBE at www.farnell.com will produce 37 different kinds. Unfortunately the technical data via the Farnell
Have you figured how many joules of energy the amp will supply with a plate circuit short compared to how much energy the gas tube will handle? 73 Gary K4FMX _________________________________________
Don't forget the thryatron - that will work at power levels that semiconductors would have no hope of coping with. -- Dr. David Kirkby, G8WRB Please check out http://www.g8wrb.org/ of if you live in
The gap I'm using is a Bourns 2035 series, 90 volt, 20KA (single pulse), hope the glitch resistor holds !! The gap through Mouser is $3.22 single piece price Arc to ground or internal arc to cathode,
Hi Gary Tricky question !! What size glitch resistor?? How fast is the plate over-current protection, i.e. how much follow on current?? How large is the filter capacitor?? What is the secondary and p
As I understand this, I really should be adding a very high speed clamp to ground from each of my GS35B cathode connections in the form of a triggered device or a spark gap. Correct? What I don't und
Hi Tomm With the GS-35B, (cathode tied to filament internally) I would use a filament choke and ground one side of the filament secondary, transformer side of the choke of course. A spark gap at the
Siemens EC 145 98 is what I came up with for the YC-156. (((73))) Phil, K5PC _______________________________________________ Amps mailing list Amps@contesting.com http://lists.contesting.com/mailman
Gerald, I buy mine from Allied Electronics. Siemens is now EPCOS. They are available in about 20 models, from 90 to 800 volts break-down. The highest price of the lot is $3.19. I use the EC-145 ($2.
from 90 to 800 volts break-down. Note that the breakdown voltage at something like a 100 or 200 volts/microsecond rise time can be as high as 1kV for a 90v beakdown gap - according to the data sheet.
This seems like a lot of trouble just to avoid using a 10a bifilar choke in the heater leads. Richard L. Measures, AG6K, 805.386.3734. www.somis.org _______________________________________________ Am
In a HF amplifier, a +HV arc to ground sometimes accompanies an intermittent VHF parasitic oscillation. The reason for the arc is that a HF tank acts as a low-pass filter, so it does not allow VHF en
I would: not ground either side of the heater supply, use a glitch-R to limit I-pk to 200a, and I would put a string of 20, 200a pk glitch diodes from the HV neg to gnd. Richard L. Measures, AG6K, 80
Tomm, I believe that what Rich is saying here is that we should treat the GS-35B just as though it were a directly heated cathode when dealing with the question of protection for the cathode and heat
I also agree with the not grounding of the filament. It has been my experience though, that 1N5408 diodes can be destroyed by a 3500vdc discharge through a 25 ohm glitch resistor. Perhaps the dischar
Even though a CT filament winding is required for filament-type/directly-heated-cathode tubes, I don't see the necessity for heater-type/indirectly-heated-cathode tubes since the heater potential is
<snip> In the case of the GS-35B, the internal connection between the cathode and the filament places the heater at RF potential so the RF choke will be required on both sides of the filament. If you