One more coax fitting question

[Catdriver]

The way I have my base scanner mounted at home (BC898T), I have to have the antenna lead- pl259 hooked to a 90 degree 259 then to the 259 to bnc adapter. Will this work alright or do I need to do something diff with the scanner to eliminate the 90 deg fitting?


Thanx,
Ron

 

[zz0468]

It'll work fine, no need to worry about it.

 

[ohiodesperado]

Yeah, for receiving it's not a big issue. The number of adapters could attenuate the signal slightly, but it's so minor for receiving that I wouldn't be concerned.

Transmitting is a different story, 90's should not be used in a transmitting line unless there is not another option. They create impedance humps in the line and develop hot spots.
Adapters, unless properly designed will do the same thing. A good adapter will taper from one internal diameter to the other smoothly and the center conductor will do the same.
This has to do with the impedance of the cable line. If you compare 50 and 75 ohm cables of similar outside diameters the center conductor is smaller in the 75 ohm cable. Adapters are no different. Granted, you would need a TDR to see the hump in the impedance of a cable with a poor design adapter on it, but it's still there.

I know it's a bit complex to understand but I hope the info helps.

 

[Catdriver]

Thank you, thats good info I didn't know....


Ron

 

[kb2vxa]

"Transmitting is a different story, 90's should not be used in a transmitting line unless there is not another option. They create impedance humps in the line and develop hot spots."

EH? I've used 90 degree adapters in transmitting service for more than 30 years with no ill effects, never heard of any either. That's only a small part of the never ending adapter/connector debate and it's all a bunch of hooey. Where do you guys come up with this nonsense?

There's one in this picture, do you think I'd use it if it was going to create an "impedance hump" or get hot on me? I knew a girl like that but she didn't transmit, thank goodness.