[TowerTalk] Ameritron Remote Controlled Switches
Steve Gehring, KL7DC
Wed, 11 Nov 1998 18:11:00 -0800
>Perfect N connectors will handle 1.5kW ICAS at 432MHz (Reference: K1FO
>in the ARRL UHF/Microwave projects book. Sorry I can't give you an exact
>quotation, someone else has the book at the moment.) I can confirm this
>at 900-1000W ICAS. The kind of "ICAS" we mean is EME contest service,
>slow Morse code for 2.5min on, 2.5min off, for 6-10 hours.
>However, with IMperfect N connectors it's anybody's guess! That's why I
>only use brand-new, top-quality N connectors for QRO on 432MHz. There
>aren't many connectors involved, so the peace of mind is well worth the
>>Besides the UHF connector, is there another alternative to the N that is
>>about the same size, but better at power handling, ease of installation,
>>and ruggedness? For example, use of the C or HN series?
>C and HN are good, but sometimes hard to find. C connectors are like a
>giant BNC so are quick to connect and have good power handling; but like
>BNC they use a rubber gasket as a spring, which becomes slack with age
>and allows the whole connector to spin. HN are like N but bigger -
>though still not as big a center pin as a PL259.
>For UHF QRO I'm gradually trying to change to 7/16 DIN, which are
>seriously large connectors good for several kW at UHF. They originated
>in Germany but are being increasingly used in cellular base stations
>world-wide, because they give reliably better connections with lower
>inter-channel IMD than N. They're gradually emerging onto the surplus
>market over here, but would be major overkill at HF!
>>Here's perplexing question. Why is the N rated for 1500V and the BNC rated
>>for 500V, with their dielectrics of air/TFE and TFE respectively (excluding
>>mating junctions)? Could it be center pin size again? Could the designers
>>have limited the current capacity through the voltage rating, referenced to
>>50 ohms with the BNC?
>Dunno, beats me Guv...
>>Wanting to stay away from clunky, labor intensive UHF connectors...
>With my background, I just can't bring myself to call them "UHF" at all.
Thanks again for the info, guys. I really appreciate the hundreds, if not
thousands of years of experience this reflector's users provide.
NOTE: I haven't heard of the 7/16 DIN rf connector. I'll have to research
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