Jon, you stated previously that you were in the resistor business. Why don't you provide a mini lecture on the inductance in helical wound "metal film" resistors of the type that are probably going t
Hairy Green Toads from Mars made Lee Roberts say: "This is the second amp that I've bought from Ameritron and it will "be the last. The first amp is a solid state amp whose finals kept "blowing. Amer
Lee, I agree, it's not the best amps in the world... but, you also did not pay a whole lot of money for the amp. 4 811's don't put out a whole lot of power. But for 6 to 700 bucks it's a hell of an a
Or you can put a series capacitor in series with the R and cancel the reactance at the frequency of instability. Oscillators don't work that way. They either have enough feedback to overcome loss an
Author: Donald.Kessler@wpafb.af.mil (Kessler Donald J LtCol HQ AFMC/DOOT)
Date: Wed, 1 Mar 2000 09:30:36 -0500
Phil, I have had the great misfortune to receive (free) two mfj "3kw" antenna tuners. Pure junk! - mediocre design and very poor implementation. I had an mfj antenna switch - also junk - it is now c
An interesting idea, Tom. A 100-ohm, 3w Matsushita MOF resistor has c. 11nH. At 100MHz, this amounts to 7-ohms of reactance. At 100MHz, roughly 200pF would be needed to cancel 7-ohms of Xl. . Howeve
A while back I did some tests with my MFJ-259 and some of the 5-watt metal-oxide resistors from Mouser, and posted my results here on AMPS. I estimated their inductance by resonating several little c
A while back I did some tests with my MFJ-259 and some of the 5-watt metal-oxide resistors from Mouser, and posted my results here on AMPS. I estimated their inductance by resonating several little c
A tuner sold by Ameritron (ATR-20) using the same inductor is rated at 750 watts CW, but there are electrical differences. The Ameritron tuner includes a peak reading meter that really reads peaks,
All standard resistors of the "tubular" type are somewhat "wound." All have inductances. The resistors I sell are thin film nichrome (OK, OK, nichrome IS used as the resistive film element in these
It's not necessarily any ringing transient. VCOs (real oscillators) are not started from a transient but basically oscillate due to the thermal noise of the transistors starting things off. Same thin
Tom -- Does this tuner currently use a Delrin roller inductor coil form? thanks -- FAQ on WWW: http://www.contesting.com/ampsfaq.html Submissions: amps@contesting.com Administrative requests: amps-R
Hi Jon, I've never seen an oscillator that required a hand crank, like an old model T Ford, to get it started. I see very few oscillators that come with a hammer so you can "bang" them to get them s
No, it has air insulation. The Oren Elliot Products roller was never used at Ameritron. It was used only by Vectronics, Dentron, View Star, Heath, and others. 73, Tom W8JI w8ji@contesting.com -- FAQ
the What is the frequency of instability? Therefore what is the reactance? On what grounds is it assumed that there is only one frequency of instability? If the "suppressor" is meant to suppress some
Author: Donald.Kessler@wpafb.af.mil (Kessler Donald J LtCol HQ AFMC/DOOT)
Date: Thu, 2 Mar 2000 10:35:23 -0500
I don't remember the nomenclature, but the antenna switch was their qro 6-position switch with receptacles for pl-259 connectors. The fundamental problem was that the connectors themselves were of o
The coil-form has air insulation? Did you mean to say ceramic insulation? Where did the Delrin roller inductor come from that reportedly melted down twice in the ARRL lab? thanks cheers, Tom -- FAQ
Tom, you said it all so eloquently! If the amplifier is going to oscillate, it will oscillate. It won't sit there and just do nothing for weeks, months, years, etc. and then suddenly WHAMMO! Too true
Don't know, I don't have the amplifier in front of me...or even know what one it is. Don't know. Same reason as given above. Might not be just one. Some amps have two, like the Clipperton. The suppr