The devices that we are (mostly?) discussing here date back to 1949: High-Frequency Matching Transformer, US Patent 2,470,307, 17 May 1949 Unfortunately Guanella muddied the waters by publishing anot
For impedance measurements on chokes, I use the same physical layout that Rick describes above. The only differences are in the calibration procedure and the mathematical processing of the raw data.
That would be me... The technical background is the same all over the world, but the cost of "named ferrite" [1] is much higher outside of the USA so cost-effectiveness is a much bigger part of the d
The word "theory" has two different definitions that are almost completely opposite to each other. The only flaw is if you use the wrong one. The US National Academy of Sciences sums it up very neatl
Waxoyl would work (if available in the USA) because it is specifically formulated to prevent corrosion in wet environments. My old moonbounce system had a rotating steel mast in a ground socket fille
Please tell us how, for future reference. -- 73 from Ian GM3SEK http://www.ifwtech.co.uk/g3sek _______________________________________________ _______________________________________________ TowerTal
When calculating tuner losses we need two separate parameters, Rs (the loss resistance) and X (the effective reactance, with capacitive effects *included*). Combining these into a single "Q" value is
Don't argue about safety with anyone who is prepared to die for his beliefs :-) -- 73 from Ian GM3SEK http://www.ifwtech.co.uk/g3sek _______________________________________________ __________________
Yes, it will. The point you are missing is that the mode of resonance changes between the two bands. On the lower band, the mode of resonance is a conventional shortened half-wave; the current has th
We don't truly mean "equalize" and "same potential" here. When MOVs conduct, they do not crowbar their two terminals together to equalize the voltages. They act more like bidirectional zener diodes,
But there aren't only two terminals at the output from a transmitter/ATU into a "balanced" feedline. There are always three terminals - the third being the transmitter's ground terminal. It is the gr
Highly recommended. I used the compression sleeve N type for years, and was very happy when they also became available in a PL259. Cable prep consists of one flush cut through the jacket, braid and i
The RFU-503 is -NOT- the type of connector that I was describing and recommending. I have tried the RFU-503 type and they are far inferior to 'European' design. The anchoring strength of the RFU-503
The design originated with a British company called Greenpar, which was bought by MA/COM, which in turn is now part of the Tyco empire. Other manufacturing licences may have been granted (eg to the M
The drawing seems correct but the photograph shows the variant with a slimmer body for RG58. I will add one to the Farnell order planned for Monday (can always use another '259) so will confirm for s
Yes, the N series from Greenpar were probably the first of that improved 'compression sleeve' type... must be well over 30 years ago now. The PL-259 variant is a relatively recent introduction, while
Ah... dreadful sorry :-) -- 73 from Ian GM3SEK http://www.ifwtech.co.uk/g3sek _______________________________________________ _______________________________________________ TowerTalk mailing list To
[...] What do you mean by "95% efficient for the total boom length"? -- 73 from Ian GM3SEK http://www.ifwtech.co.uk/g3sek _______________________________________________ _____________________________
For SDS+ you can also buy a 0.5in sq socket adapter (eg www.screwfix.com/p/sds-plus-nut-driver/16662). The flat end makes a good hammer for driving rods, and you can add a socket of just the right si
The 1000ft TV tower serving the northern part of the Netherlands caught fire and collapsed yesterday: <http://www.youtube.com/watch?v=VdMLiL4vlHc> -- 73 from Ian GM3SEK http://www.ifwtech.co.uk/g3sek