High freq RF switch

[amdx]

I'd like to build an RF switch for cable TV.
I want to be able to switch off the cable.
The high end is about 900Mhz.
I would build it in a two way splitter box.
In , out, and control.
Any circuit suggestions would be appreciated.
Would a 2N 5109 work at this freq?

Mike

 

[Paul Burridge]

I'd like to build an RF switch for cable TV.
I want to be able to switch off the cable.
The high end is about 900Mhz.
I would build it in a two way splitter box.
In , out, and control.
Any circuit suggestions would be appreciated.
Would a 2N 5109 work at this freq?

Do you really need 100mW capability? This *is* a receiver, right? The
device you mention is better as an amp than a switch. It may well work
(up to 1.2Ghz) but there are more suitable devices around for your
purposes.

 

[John Larkin]

I'd like to build an RF switch for cable TV.
I want to be able to switch off the cable.
The high end is about 900Mhz.
I would build it in a two way splitter box.
In , out, and control.
Any circuit suggestions would be appreciated.
Would a 2N 5109 work at this freq?

Mike

Why not a relay? Or maybe use a pin diode to short out the signal or a
couple of pin's to make a series:shunt signal killer.

I'd guess you could do it with a series/shunt schottky diode pair if
pin's aren't handy.

John

 

[Fred Bloggs]

I'd like to build an RF switch for cable TV.
I want to be able to switch off the cable.
The high end is about 900Mhz.
I would build it in a two way splitter box.
In , out, and control.
Any circuit suggestions would be appreciated.
Would a 2N 5109 work at this freq?

Mike

Look at the RF relays at http://www.digikey.com -cable signals can be as
high as 20dBm.

 

[Tam/WB2TT]

Look at the RF relays at http://www.digikey.com -cable signals can be as
high as 20dBm.

I was going to suggest the same thing. These things are rated to 900MHz, and
reasonably priced. I believe Mouser carries the same thing. Also, why bother
with a transistor switch? You need a switch to operate the transistor. You
could probably just get by with running the RF to the switch if you don't
want to use a relay. Use a wafer switch and run the coax right up to the
switch.

Tam

 

[maxfoo]

I'd like to build an RF switch for cable TV.
I want to be able to switch off the cable.
The high end is about 900Mhz.
I would build it in a two way splitter box.
In , out, and control.
Any circuit suggestions would be appreciated.
Would a 2N 5109 work at this freq?

Mike

Call Hittite for a free eval board and/or chip of the SPDT, CATV DC-2.5 rf
switch. datasheet below...
http://www.hittite.com/product_info/product_specs/switches/hmc348lp3.pdf

 

[Don Lancaster]

I'd like to build an RF switch for cable TV.
I want to be able to switch off the cable.
The high end is about 900Mhz.
I would build it in a two way splitter box.
In , out, and control.
Any circuit suggestions would be appreciated.
Would a 2N 5109 work at this freq?

Mike

PIN diodes are an infiniely better choice.
--
Many thanks,

Don Lancaster
Synergetics 3860 West First Street Box 809 Thatcher, AZ 85552
voice: (928)428-4073 email: [email protected]

Please visit my GURU's LAIR web site at http://www.tinaja.com

 

[Don Pearce]

PIN diodes are an infiniely better choice.

And the right choice would be a BAT18 dual PIN diode, which will
perform this task beautifully.

d

Pearce Consulting
http://www.pearce.uk.com