You can stack some cores, but maybe a more elegant solution would be to cut a small gap with a fret saw into the core. That would interrupt the magnetic path and prevent saturation. Fill the gap with
I am building a 3.5-30 MHz amp with 2 grid-driven 4CX250Bs. I have already built the screen grid supply with resistors from the +2000V plate supply, shunted by a string of Zener diodes to ground. The
Should linear size (1/2" O.D., by 1/4" I.D. Angel Vilaseca HB9SLV _______________________________________________ Amps mailing list Amps@contesting.com http://lists.contesting.com/mailman/listinfo/am
Hi, In a tetrode amp, the screen voltage must be well regulated. A lot of ripple on the plate voltage does not matter, providing the plate voltage is well regulated. On the other hand, how about a tr
How can a gassy tube cause a flashover? You would expect the electrons to collide with gas molecules within the tube, hence to decrease plate current. But how can this possibly cause a short circuit
Hi all, I sent an order to RF parts several weeks ago. Received nothing. Tried to e-mail them at several of their addresses. No answer. Are they still in business? Angel Vilaseca HB9SLV _____________
Hi, On Ebay, I saw some russian L-couplers for sale. They are made of two coils, both wound on a virtual sphere. One of the coils is slightly smaller and placed within the larger one. The inner coil
Hi, On almost every grounded-grid triode amp design I have seen, the filament choke is an abt 35 uH coil wound on a 1/2 inch dia, 7-inch long ferrite rod. Such a large unit is a bit cumbersome. Inste
Manfred, If this project is the same quality and benefit to the home-builder as your Fodtrack (and I am sure it will be), please go ahead! Angel HB9SLV Manfred Mornhinweg a écrit : ___________
John, Thanks for this post. I am keeping it as a reference. I have a couple of questions: How can the Harris filter (7 H * 0.25 uF = 1.75) and the Galaxy filter ( 4 H * 0.1 uF = 0.4 ) be both resonan
Jim I see from your simulation that a 2 H inductance is typical for a HV secondary. I wonder if a HV transformer from a microwave oven cold be recycled in a HV power supply, using its secondary windi
Marv, Thank you for this very useful information. Maybe the primary of a microwave oven could be wired in series with the secondary (forward or backwards, depending on the inductance you want) and be
Hi all, To automatically regulate blower speed, how about the following: Assume you have a 30 W, 110 V blower. Wire a 110 V - 6 volt 30 VA transformer secondary in series with the HV primary transfor
Hi, For my 3000 V , 500 mA power supply, I will use some microwave oven rectifiers, which are rated 7 Kv, 500 mA. To increase the current safety margin I will wire two rectifiers in parallel in each
Thanks for the answers. The 1N 5408 seem to be the best way to go. I will buy some. 73 Angel Vilaseca HB9SLV k7rdx a écrit : _______________________________________________ Amps mailing list A
Hi, I have several used 4CX250Bs that I want to try to put to use. State of the tubes is unknown. They are pullouts. I will test them including hipot, as was detailed on this list a few days ago. Now
Hi, I have a nice 1 KW HV transformer with a 110 V primary. Unfortunately, mains in the shack is 220 V only. I also have several unused transformers with a 220 V primary tapped for 110 V. So I was th
Another situation where excessive wire length can lead to unwanted resonance effects (overheating) is the plate choke. If the plate choke was wound on a ferrite rod, or toroid, much less wire length
Hi, I have a microwave oven transformer that I plan to use for my next HV power supply. With the secondary unloaded and 220 V into the primary, I measured 670 mA through it. This is a 220 V unit so t
Good mews then! My MOTs are OK. Bad news: although no real power is delivered to my house, the power company will bill me for it! :-) Thanks for your help, guys! Angel Vilaseca HB9SLV Alex a écrit :