THIS IS IT! I NEED AN ANTENNNA SWITH.

[Tripple Nickel]

If you have in your area "YARD SALES/GARAGE SALES" look around, you would be surprised what you can find.
Last Saturday I stumbled on a box full of wires etc. I sat in the shade and rumbled thru it. Wala, I found a really nice Avanti Vertical/Horizontal switching box in perfect condition, stainless case @ that for $1.00. It is perfect for my TWO radio set-up. Also got (2) of the large foam jumper cables $0.50 each, and a inline SWR Tester for $1.00. It's out there, be patient. People that have CB stuff is getting rid of it, just ask.
555 3's and good evening to you/yours

 

[Lil'Yeshua]

I have a MFJ-1702. I used it to switch between radios sharing the same antenna. I either turned off the radio I wasn't using or turned it's rf gain all the way down while using the other radio to prevent overload.

 

[Robb]

:laugh: BINGO!!!


As a note, beware that some cheap switches are nothing more than a single pole double throw toggle switch and are crap. The better switches are housed in a metal box and is not a simple toggle switch and look like this inside. This is the Diawa CS-201 switch.

Yeah; the one I have/use looks just like the one you have on the inside. No doubt just re-branded and re-packaged. But they are really built quite strong. Took mine apart and cleaned the switch and put some decent grease on the ball bearing/moving block ass'y.

I'd buy another if I needed one, as the fair price and decent quality are both there - IMO.

 

[Robb]

:laugh: BINGO!!!


As a note, beware that some cheap switches are nothing more than a single pole double throw toggle switch and are crap. The better switches are housed in a metal box and is not a simple toggle switch and look like this inside. This is the Diawa CS-201 switch.

Yeah; the one I have/use looks just like the one you have on the inside. No doubt just re-branded and re-packaged. But they are really built quite strong. Took mine apart and cleaned the switch and put some decent grease on the ball bearing/moving block ass'y (circled).

I'd buy another if I needed one, as the fair price and decent quality are both there - IMO.

 

[unit_399]

Brand:MFJ
Manufacturer's Part Number:MFJ-1702
Part Type:Antenna Switches, Manual
Product Line:MFJ 1702 Antenna Switches
DXE Part Number:MFJ-1702
Antenna Switch Positions:2-port
Antenna Switch Connector Type:UHF female, SO-239
Switch Impedance:50 ohms
Switch Insertion Loss:Less than 0.20 dB
Switch Isolation:More than 60 dB
All Ports Grounded Position:No
Power Rating (0 to 30 MHz):2,500 W PEP/1,000 W CW
....................................................................................

This is the spec sheet for the MFJ switch that Robb recommends. They claim that the switch has an impedance of 50 ohms. I don't understand this, as I see nothing resistive, capacitive or inductive about it. Can anyone explain how the impedance of this switch is caalculated ???
- 399

 

[Robb]

Eh? If you are asking me - wouldn't have a clue. Perhaps MFJ's technical writer didn't have his morning coffee? Either way, if it is a Daiwa or re-badged for MFJ, it is still the same box. It really is built very solid. The box is of course a machined casting; not a lightweight switch in a p-box whatsoever. But for the price it surely beats the crap out of those really cheap CB antenna switches - which have so little separation and poor insulation they really should be embarrassed to put their logo on it. For ~$20, it kicks the crap out of the competition. Now, that is a recommendation.

 

[Lil'Yeshua]

Maybe it's because of it's coaxial properties would be the best possible answer.

 

[Captain Kilowatt]

Brand:MFJ
Manufacturer's Part Number:MFJ-1702
Part Type:Antenna Switches, Manual
Product Line:MFJ 1702 Antenna Switches
DXE Part Number:MFJ-1702
Antenna Switch Positions:2-port
Antenna Switch Connector Type:UHF female, SO-239
Switch Impedance:50 ohms
Switch Insertion Loss:Less than 0.20 dB
Switch Isolation:More than 60 dB
All Ports Grounded Position:No
Power Rating (0 to 30 MHz):2,500 W PEP/1,000 W CW
....................................................................................

This is the spec sheet for the MFJ switch that Robb recommends. They claim that the switch has an impedance of 50 ohms. I don't understand this, as I see nothing resistive, capacitive or inductive about it. Can anyone explain how the impedance of this switch is caalculated ???
- 399

Perhaps the silver plated straps inside the formed metal pathways present a characteristic impedance of 50 ohms just like coax cable does. Perhaps it was tested with a VNA. The most likely answer however is that since MFJ knew it would be used in a 50 ohm system and since the impedance bump it created is not too bad (similar to PL-259's creating an impedance bum) they simply threw bullshit to the wind and called it a 50 ohm switch. :laugh:

 

[unit_399]

Eh? If you are asking me - wouldn't have a clue. Perhaps MFJ's technical writer didn't have his morning coffee? Either way, if it is a Daiwa or re-badged for MFJ, it is still the same box. It really is built very solid. The box is of course a machined casting; not a lightweight switch in a p-box whatsoever. But for the price it surely beats the crap out of those really cheap CB antenna switches - which have so little separation and poor insulation they really should be embarrassed to put their logo on it. For ~$20, it kicks the crap out of the competition. Now, that is a recommendation.

I agree 100%, Robb. I wasn't questioning the quality of the item, just the 50 ohm impedance spec.

- 399

 

[Lil'Yeshua]

Perhaps the silver plated straps inside the formed metal pathways present a characteristic impedance of 50 ohms just like coax cable does. Perhaps it was tested with a VNA. The most likely answer however is that since MFJ knew it would be used in a 50 ohm system and since the impedance bump it created is not too bad (similar to PL-259's creating an impedance bum) they simply threw bullshit to the wind and called it a 50 ohm switch. :laugh:

Yeah! What he said. ;O