Jumper cable question

[yankees6161]

I will be installing my antenna out side this spring, will be using lmr400 cable. Should I use a lighter wight jumper cable to go in to the scanner or is it he 536 bnc connector strong enough to support the lmr400? If you suggest a jumper cable what cable would you use? I was thinking of something like a 4 foot jumper using 195 or 240 low loss cable

 

[n1chu]

Your thinking is correct. LMR400 can put undo strain on the radio. I also use LMR400. I use a short jumper of low los cable that’s much more flexible. Just keep it as short as practical and you are good. Mine is about 2 feet long but 4 feet shouldn’t be a problem when using the low loss stuff.

 

[mmckenna]

I was thinking of something like a 4 foot jumper using 195 or 240 low loss cable

That would absolutely be suitable. For that short a run, so would RG-58.
Do get correctly mating connectors, in other words, don't use adapters. If your LMR-400 has a male N connector on the radio end, make sure you get a jumper cable that has a female N connector to match it.

 

[yankees6161]

Do get correctly mating connectors.

That was my plan. I might use only one N female bulkhead in the eve of my roof

 

[RFI-EMI-GUY]

RG 58/AU or better RG142 cable. Be sure to install a grounded surge protector where the LMR400 terminates inside the house.

RG142 Coaxial Cable, PTFE, M17/060-RG142, 50 ohm, 0.195 dia, MFR: Thermax/Harbour Industries

RG142 Coaxial Cable, PTFE, M17/060-RG142, 50 ohm, 0.195 dia, MFR: Thermax/Harbour Industries

www.rfparts.com

 

[prcguy]

RG 58/AU or better RG142 cable. Be sure to install a grounded surge protector where the LMR400 terminates inside the house.

RG142 Coaxial Cable, PTFE, M17/060-RG142, 50 ohm, 0.195 dia, MFR: Thermax/Harbour Industries

RG142 Coaxial Cable, PTFE, M17/060-RG142, 50 ohm, 0.195 dia, MFR: Thermax/Harbour Industries

www.rfparts.com

Double shielded silver plated RG-142 is great stuff for duplexer jumpers and such but I think its overkill for a short jumper to a scanner and its pretty stiff. If the OP can get away with a 2ft jumper then a good US made RG-58 stranded center conductor should be fine at any frequency the scanner can receive.

 

[RFI-EMI-GUY]

Double shielded silver plated RG-142 is great stuff for duplexer jumpers and such but I think its overkill for a short jumper to a scanner and its pretty stiff. If the OP can get away with a 2ft jumper then a good US made RG-58 stranded center conductor should be fine at any frequency the scanner can receive.

True but while I have used both, I have had far more RG58 cables wear out at the connector from flexing.

 

[prcguy]

True but while I have used both, I have had far more RG58 cables wear out at the connector from flexing.

Not my hand made cables with US manufactured cable and thick hot glue heat shrink strain reliefs. Here are a couple of examples, an Alpha Wire RG-58 C/U and a fancy Huber+Suhner home made jumper cable.

 

[GROL]

I use marine shrink tubing for all my cable ends to prevent water ingress and provide strain relief. Marine shrink tube has hot glue inside and seals up nicely. Harbor Freight sells an assortment box of different size marine shrink tubings. I have lots of cables I made for portable operation and they last a long time. Also use self sealing silicone tape on outside junctions.

 

[yankees6161]

Thanks for all of the suggestions

 

[avaloncourt]

I also use LMR 400 with a short thin cable at the SDS200.

 

[RFI-EMI-GUY]

Not my hand made cables with US manufactured cable and thick hot glue heat shrink strain reliefs. Here are a couple of examples, an Alpha Wire RG-58 C/U and a fancy Huber+Suhner home made jumper cable.


View attachment 136325

What is the trick to getting hot glue inside the shrink? Or is it some premade shrink product.

 

[mmckenna]

What is the trick to getting hot glue inside the shrink? Or is it some premade shrink product.

Premade.
It's usually referred to as "Marine Grade". The heat shrink is lined with the hot melt adhesive, so when you shrink the tube, the adhesive melts and flows.

Or, use an itty bitty hot glue gun…..

 

[prcguy]

What is the trick to getting hot glue inside the shrink? Or is it some premade shrink product.

Premade. My local electronics parts store has 4ft lengths in many diameters. Sometimes I'll have a cable and connector combination where the part of the connector I want the heatshrink over is much larger than the cable and the heatshrink may not shrink enough. In those cases I will cut the short length of heatshrink to span the cable and connector that's close to the connector diameter but a little smaller, then I'll use duck bill pilers to stretch the heatshrink so it fits over the connector. Now with heat it will shrink and fit both the connector and cable.

 

[RFI-EMI-GUY]

I have actually repaired stuff with Hot Glue. Very underated product.