-- ORIGINAL MESSAGE --(may be snipped) REPLY: No, it's not a pi network, it really is just an "L" network, made up of the tube's output capacitance (including a few pF of stray capacitance) and a coi
I notice the SPE 1.3K-FA amplifier is using a single LDMOS transistor to achieve a peak of about 1500 watts output. I am wondering how they do this and stay linear over the full 360 degree RF cycle.
I think Tom, W2SC has the answer. When SPE says a "single device" they mean a single package which has two transistors in it, and they are running them in push-pull in the conventional manner. Withou
-- ORIGINAL MESSAGE --(may be snipped) REPLY: That seems to be the most likely answer. Thanks, 73, Bill W6WRT _______________________________________________ Amps mailing list Amps@contesting.com htt
That is a truly amazing piece of work. I notice the large PC board which is apparently the controller for the stepper motors. Did you build that yourself too? That must have been as much work as the
-- ORIGINAL MESSAGE --(may be snipped) REPLY: That is enough capacitance and voltage. The only question is ripple current rating, which might be hard to find. I would use it but have a plan to change
-- ORIGINAL MESSAGE --(may be snipped) REPLY: Not true. If driven too hard too long the 2K-FA simply drops down to a lower power level. I own one, that's how they work. They are cook-proof. 73, Bill
-- ORIGINAL MESSAGE --(may be snipped) REPLY: The 2K-FA is not brick-on-the-key for RTTY at 1500 watts. You will get about ten seconds of carrier and then it will drop down to the MID power setting.
-- ORIGINAL MESSAGE --(may be snipped) REPLY: Cool, compact, headphones. 73, Bill W6WRT _______________________________________________ Amps mailing list Amps@contesting.com http://lists.contesting.c
-- ORIGINAL MESSAGE --(may be snipped) REPLY: And this is one reason why AM has become mostly a curiosity. :-) 73, Bill W6WRT _______________________________________________ Amps mailing list Amps@co
-- ORIGINAL MESSAGE --(may be snipped) REPLY: There is an old trick from the vacuum tube TV days: Cool the tube down and breathe on it. The moisture in your breath will condense more heavily on the p
-- ORIGINAL MESSAGE --(may be snipped) REPLY: The best efficiency would be obtained by turning off the transmitter. 73, Bill W6WRT _______________________________________________ Amps mailing list Am
-- ORIGINAL MESSAGE --(may be snipped) REPLY: Good question. I heard years ago that over long periods of time some of the molecules in a transistor could "migrate" to undesired areas, so in that sens
-- ORIGINAL MESSAGE --(may be snipped) REPLY: So, absent migration, do transistors "wear out"? 73, Bill W6WRT _______________________________________________ Amps mailing list Amps@contesting.com htt
-- ORIGINAL MESSAGE --(may be snipped) REPLY: "Bad" is mostly in the eye of the beholder. A "good" tube should match the plate current curves shown in the data sheet. That is, for a given plate volta
-- ORIGINAL MESSAGE --(may be snipped) REPLY: Mouser has these for $0.42 each. 73, Bill W6WRT _______________________________________________ Amps mailing list Amps@contesting.com http://lists.contes
-- ORIGINAL MESSAGE --(may be snipped) REPLY: I agree with Jim but I would qualify that a little. The 6A10s must be identical, i.e. from the same manufacturer and same batch. Do not try to mix and ma
-- ORIGINAL MESSAGE --(may be snipped) REPLY: As I understand it, all diodes have an avalanche (zener) voltage. The question is whether it can withstand the power dissipated at that voltage and rever
-- ORIGINAL MESSAGE --(may be snipped) REPLY: If you're going to do this, the capacitors should be closely matched for capacitance lest you introduce even more variation across the diodes. Capacitors
That does look interesting. I didn't see a link to download the owner's manual so I will be emailing them to see if one is available. Also, I didn't see any mention of duty cycle rating except it did