[AMPS] RE High Power Coax Switches

[Kimo C. Chun]

A number of days late (wasn't a subsciber when I first tried to post)
but for what it's worth.

The 1997 Bird Catalog lists the Series 71, 72 and 74 Coaxial Switches, of
various numbers of positions and up to two circuits (special applications).

If I may publish their table (without their permission):

Frequency       VSWR            Insertion Loss  Max RF Power Rating @ 65 C.
100 MHz         negligible      0.02 dB         850W
1000 MHz        1.06 max.       0.09 dB         200W
4000 MHz        1.30 max.       0.22 dB         75W

Useful Freq Range: DC to 10 GHz
Maximum RF Voltage: 500 Volts RMS
Attenuation to Unused Channel: 75 dB (cross talk)
Ambient Temperature Range: -60C to +65C
Weight: Varies by model, approx. 2-1/2 lbs. (1.1 kg)

"The switching mechanism is 4-1/2" of RG-87/u Teflon Cable..."

The catalog does not say whether these are continuous duty ratings.
Certainly the more technically inclined should be able to calculate
the probable capabilities for SSB or other services based on this
information. I hope this helps some peoples questions.

Also, remember that the pin on the Type-N is quite small. In
reality I believe the common PL-259 will handle more power but
not at higher frequencies somewhere around VHF and above (other
problems as well).

I am not an expert in this area but that is my understanding.

Aloha, 73

Kimo Chun, KH7U

kimo@lava.net




>[AMPS] RE High Power Coax Switches

>I use Bird Coax switches is test facilities I design because of their power
>handling ability and extremely low loss injto UHF.  I have yet to replace one
>in the last 10-years of using them.  A three position switch is in the $300
>range  if that is any help.
>
>73's
>Bill James  WA2QHL
>Trustee  K2BAR

>I have one of those too.
>They are realy great switches but the real charm of these is for UHF
>frequencies.
>
>The center pins are "pulled out" by the knob and then you turn it to the
>desired position then push the pins back in. No contacts.
>
>Very clever.
>
>VERY expensive.
>
>73, Dan Magro W7RF, (member SCDXC, SCCC)


>Bird made a nifty 6 position coax switch using Type N connectors once up
>a time.  The "Knob" was a pull, turn, Push ordeal.  Looks real heavy
>duty, but I've heard a few second opinions on N connectors.  I have such
>an animal.. what's it worth?
>
>'73  KI4z



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