Patch/Jumper Cables

[Diverdan86]

Good morning! Question from a new(er) ham: I have a small radio room station setup in my shop and am discovering I need a dozen or so patch/jumper cables to run between all the equipment (meters, tuners, filters, switches, etc.) to make it all work. I have also discovered that I need the coax jumpers to be fairly flexible due to the tight spaces.

The question is, what kind / size of coax jumper do you recommended for short runs on? RG-58? RG-213? RG-142? If I follow the logic of some hams online I would have ONLY LMR400 (or better LOL) for every 2-5 foot run.

Clarifying info:

• Longer runs of coax from my exterior antennas are LMR 400 into the shop (75 - 100 feet), then RG-8X into the radio room (30 feet)
• Max length of jumper I need is 5 feet, min. 1 foot or so
• I run 100 watts barefoot on HF/6m and 50 watts VHF/UHF
• *If* I end up with an HF amplifier come solar minimum, I cannot see doing more than 300 watts or so on SSB, so I do not see myself running legal limits or anything
  

Thanks in advance!

73,
Daniel - KK7MBS

 

[mmckenna]

For what you are doing, RG-58 is good. It's flexible, inexpensive, easy to get connectors for, easy to terminate, and available from dang near anywhere. Decent crimp tools are out there, or you can solder on connectors. I keep the scraps left over from mobile installs to make jumpers. For a few feet, it just doesn't make that much of a difference.

I think anything more expensive gets to be a moot point with an installation like yours. Not that it would hurt anything, but for most ham use, you won't notice the difference on short runs like jumpers.

 

[Diverdan86]

For what you are doing, RG-58 is good. It's flexible, inexpensive, easy to get connectors for, easy to terminate, and available from dang near anywhere. Decent crimp tools are out there, or you can solder on connectors. I keep the scraps left over from mobile installs to make jumpers. For a few feet, it just doesn't make that much of a difference.

I think anything more expensive gets to be a moot point with an installation like yours. Not that it would hurt anything, but for most ham use, you won't notice the difference on short runs like jumpers.

Awesome thank you. It is amazing how many hours of research you can do, only to come to an indeterminate conclusion. Then you finally ask an Elmer and bang - done in a few sentences. Thanks again!

 

[mmckenna]

Awesome thank you. It is amazing how many hours of research you can do, only to come to an indeterminate conclusion. Then you finally ask an Elmer and bang - done in a few sentences. Thanks again!

Well, comes down to budget. You can always get better, but for most ham/hobby use, the difference is so slight on a short run that it probably would not be noticeable.

Maybe get better jumpers, like RG-142, for your test gear, and use RG-58 for radio hookups.

 

[Diverdan86]

Well, comes down to budget. You can always get better, but for most ham/hobby use, the difference is so slight on a short run that it probably would not be noticeable.

Maybe get better jumpers, like RG-142, for your test gear, and use RG-58 for radio hookups.

Interesting. It seems like the two schools of thought are ‘use the lowest loss line for jumpers humanly possible’, and the second ‘don’t use any coax jumpers better than X , because you’re just wasting your money at frequencies at or below 70cm’. Would it be accurate to say your opinion is to get the lowest loss jumpers that you can afford and fit into the environment (i.e. it’s not a waste)?

 

[rf_patriot200]

FYI, R and L Electronics has a 24 hour sale that changes every day, and they frequently have 4 packs of rg-58 jumpers, and then 10 packs of PL-259's for those who want to build their own.

 

[mmckenna]

Interesting. It seems like the two schools of thought are ‘use the lowest loss line for jumpers humanly possible’, and the second ‘don’t use any coax jumpers better than X , because you’re just wasting your money at frequencies at or below 70cm’. Would it be accurate to say your opinion is to get the lowest loss jumpers that you can afford and fit into the environment (i.e. it’s not a waste)?

Lowest loss is a good thing, but it gets expensive.
And the trade off is fractions of a Decibel, at best.

For a 3 foot jumper at 800MHz:
RG-58 = 0.381dB loss
LMR-200 = 0.280dB loss
LMR-240 = 0.214dB loss
VHF/UHF the losses will be less. On HF, you probably don't have the lab grade equipment to even measure the loss differences, it's in hundredths of a Decibel.

You are looking at 0.1dB to 0.16dB loss on 800MHz. Your ears are not going to notice that. Is it worth the extra money for a difference you are not going to notice?

 

[Grounded]

As an amateur, the primary concern is cost; performance is secondary. The essential goal is to limit your losses to 2 dB or less from your Transmitter to the antenna. I would never use a CB coax (RG58),.

 

[Diverdan86]

As an amateur, the primary concern is cost; performance is secondary. The essential goal is to limit your losses to 2 dB or less from your Transmitter to the antenna. I would never use a CB coax (RG58),.

So what would you use / recommend for this application?

 

[vagrant]

mmckenna provided the loss numbers, but for short runs I prefer LMR-240UF (Ultra Flex). It’s probably around fifty cents more per foot than RG-58. Regular LMR-240 is stiff and not what you’re looking for.

Consider the cost of how many jumpers you need and the length of each. If you need 10’ overall, will the extra $5 for LMR-240UF be worth it, or a waste?

 

[Diverdan86]

mmckenna provided the loss numbers, but for short runs I prefer LMR-240UF (Ultra Flex). It’s probably around fifty cents more per foot than RG-58. Regular LMR-240 is stiff and not what you’re looking for.

Consider the cost of how many jumpers you need and the length of each. If you need 10’ overall, will the extra $5 for LMR-240UF be worth it, or a waste?

Awesome thank you for the advice!

 

[AK9R]

This is what I use:
1 foot DX Engineering DXE-8XDX001 DX Engineering's RG-8X 50-ohm Coax Cable Assemblies | DX Engineering
3 feet DX Engineering DXE-8XDX003 DX Engineering RG-8X PL-259 Low-Loss 50-ohm Coax Cable Assemblies | DX Engineering
6 feet DX Engineering DXE-8XDX006 DX Engineering RG-8X PL-259 Low-Loss 50-ohm Coax Cable Assemblies | DX Engineering
These all use RG-8X DX Engineering DXE-8X DX Engineering RG-8X 50-ohm Bulk Coaxial Cable | DX Engineering

Other lengths, cable types, and connectors are available.

 

[Diverdan86]

This is what I use:
1 foot DX Engineering DXE-8XDX001 DX Engineering's RG-8X 50-ohm Coax Cable Assemblies | DX Engineering
3 feet DX Engineering DXE-8XDX003 DX Engineering RG-8X PL-259 Low-Loss 50-ohm Coax Cable Assemblies | DX Engineering
6 feet DX Engineering DXE-8XDX006 DX Engineering RG-8X PL-259 Low-Loss 50-ohm Coax Cable Assemblies | DX Engineering
These all use RG-8X DX Engineering DXE-8X DX Engineering RG-8X 50-ohm Bulk Coaxial Cable | DX Engineering

Other lengths, cable types, and connectors are available.

I'll check them out. Thanks!

 

[mmckenna]

I would never use a CB coax (RG58),.

I wouldn't refer to RG58 as a "CB coax".
I've got about 100 permanent NMO mounts at work running 800MHz and VHF public safety stuff. All of them use RG-58 and work just fine.

Important part is to look at the entire system and design based on the needs. If a communications path comes down to depending on 0.1dB of loss as the make or break point, you've got much bigger issues to solve than a 3 foot long jumper.

 

[bharvey2]

My coax of choice for short jumpers (1-3ft or so) is LMR 240. It's a pretty decent coax, is fairly low loss and and I have lots of it laying around. However, for frequently used/moved jumpers, it's pretty stiff and will tend to break down if flexed too often. For short jumpers that are connected/disconnected/moved frequently, good quality RG58 works fine. It's often used with NMO mounts for mobile installs and works fine for that. Noting the numbers that MMckenna posted earlier, it doesn't pose much of a problem in most real world applications.

 

[rf_patriot200]

As an amateur, the primary concern is cost; performance is secondary. The essential goal is to limit your losses to 2 dB or less from your Transmitter to the antenna. I would never use a CB coax (RG58),.

MOST mobile Commercial antennas you see, will use rg58u besides cb so I'm not sure what you think the difference is ?

 

[rf_patriot200]

As an amateur, the primary concern is cost; performance is secondary. The essential goal is to limit your losses to 2 dB or less from your Transmitter to the antenna. I would never use a CB coax (RG58),.

Also your coaxial loss with a typical mobile installation using rg58 will NOT be anywhere remotely close to 2 db.