Coax switch?

[Shadetree Mechanic]

How about a duplexer? I might get one for my scanner.
https://www.mfjenterprises.com/Product.php?productid=MFJ-916B

 

[TheRealPorkchop]

I looked at those too. There’s a lot of options, I just want to make sure I don’t ruin a radio and then have to work on it. I have enough of that without causing myself more work, haha.

 

[338_MtRushmore]

How about a duplexer? I might get one for my scanner.
https://www.mfjenterprises.com/Product.php?productid=MFJ-916B

View attachment 27753

What purpose would that serve with a scanner?

 

[Captain Kilowatt]

Been using a couple MFJ's with lightning protection for several years now, and never had a problem...use them for switching two radios with separate amps hooked up, to one dual polarity antenna...

https://www.ebay.com/itm/MFJ-1702C-...=item1a07ed16b5:g:Zi4AAOSwcBhWafGr:rk:49:pf:0

Those are Daiwa CS-201 clones. I use the Daiwa switches and they work well even at VHF.

 

[jessejamesdallas]

As long as one radio doesn’t feed the other and cause an issue, I’m fine with whatever the brand is. I have my A99 hooked directly to my 2995DX, sometimes I’d like to be able to test other radios on the antenna without having to unhook the 2995.

Once this tower gets up then things may change and I might not have a use for a switch.

They will feed over from one to another if both set-ups are turned ON...(least when talking) I just turn on the set-up I'm going to be using at the time...I have one radio I prefer for SSB, the other set-up is more for AM.

 

[jessejamesdallas]

Those are Daiwa CS-201 clones. I use the Daiwa switches and they work well even at VHF.

Think one of mine is a Daiwa, and the one with the Lightning protection diode is the MFJ

 

[Shadetree Mechanic]

What purpose would that serve with a scanner?

I was thinking that I could use it to hook the scanner to my big antenna? Maybe this would limit the band width too much?

 

[jon666]

i used to make my own. when i had my drill press.

 

[338_MtRushmore]

I have actually read that the Chinese switches aren't horrible at all for hf. I also didn't realize that mfj just solders a gas tube in for lightning protection.

Any idea what voltage gas tube would be ideal for this? Any idea what kind of switch ratings would be needed for legal limit if I were to build one?

 

[oldtymer]

If RF leaks into another antenna no harm no foul.
If RF leaks into the other radio & even if it is turned off you can damage the front end.
Alpha Delta switch rated at 60db separation can still leak RF into other positions.

 

[Shadetree Mechanic]

The switches that shunt to ground when deselected would seem to be best for switching radios. That way the front ends don't get damaged. The MFJ switches that I showed do this.

 

[338_MtRushmore]

If RF leaks into another antenna no harm no foul.
If RF leaks into the other radio & even if it is turned off you can damage the front end.
Alpha Delta switch rated at 60db separation can still leak RF into other positions.

Where did you find specs on the alpha delta? I can't find much of anything on them.

 

[oldtymer]

The switches that shunt to ground when deselected would seem to be best for switching radios. That way the front ends don't get damaged. The MFJ switches that I showed do this.

Where did you find specs on the alpha delta? I can't find much of anything on them.

Yes the unused terminals shunt to grnd but some RF can still bridge over, especially
if you are running an amplifier.
It happened to a friend of mine.

I'm pretty sure the specs are on their website or on the packaging they come in.

 

[fogdog]

I have a B&W Switch like the one shown here. It's a CS-3G. It was given to me from a friend and Elmer. It works perfect for me.

 

[jessejamesdallas]

If RF leaks into another antenna no harm no foul.
If RF leaks into the other radio & even if it is turned off you can damage the front end.
Alpha Delta switch rated at 60db separation can still leak RF into other positions.

Guess I'm "OK"...been set-up like this now for a couple years and no problems...not running a ton of watts either...now probably next week everything will go south on me since I said "I've never had any problems".