The QRPer Board

As I look on the reports of past operations, I see many use one of the subject cables.

RG-174 is much cheaper and I believe has less loss.

RG-316 is more costly and has a greater loss.

I am not trying to stir the pot, I am looking for knowledge that I cannot seem to find online.

Could you please share your logic for using either of those cables.

Thank you.

https://www.alphaantenna.com/wp-content ... -I-use.jpg



consider that every 3dB of gain or loss the power doubles or halves, so a 3dB cable loss means that the antenna will receive half of the TX power and the receiver will see half of the incoming signal intensity, all this without taking in account the other losses (e.g. impedance transformer, ATU, ...), also, 1 "S point" corresponds to a signal difference of 6dB (at least on HF)

make an educated guess

I don't think you will see much difference when using short runs (around 25' or so). I have heard 316 is tougher, but it's also more expensive. I have a 20' length of 174 that's going on 5 years and about 100 outings. Never had any issues with it.

Good luck!

N8TGQ wrote: ↑Sat Apr 27, 2024 6:54 pm I don't think you will see much difference when using short runs (around 25' or so). I have heard 316 is tougher, but it's also more expensive. I have a 20' length of 174 that's going on 5 years and about 100 outings. Never had any issues with it.

Good luck!

so... what's your pick, and why ?

The 20' length I mentioned in my reply.

Why? Cause it was the first one I hit when I searched!

I was asking the OP...

anyhow, 20ft of RG174 at 10MHz will have a loss of 0.6dB where the same lenght of the "humble" RG-58 will show a loss of 0.2dB not significative, sure, but when it comes to QRP/QRPp it's always a good idea reducing losses as much as possible, and then we don't know which length of coax the OP needs

I carry a 15 ft piece of RG316 feed line (with male BNC connectors at each end) in each of my field kits. My reasons are:

• A 15 ft piece of RG316, as RG174, is light weight. I have to carry it with the rest of my gear, sometimes for short distances, and sometimes for miles.
• Losses on RG316, or RG174, feedline are small at HF frequencies, particularly for shorter lengths. The 15 ft length has served me well for deploying my end-fed wire antennas.
• RG316 is robust, and has stood up well to the rigors of my use in the field. It coils nicely, and resists cuts and abrasions.
• I have never felt handicapped by this feedline when operating QRP CW in the field.

Best 73 de Brian - K3ES

Andrew (grayhat) wrote: ↑Sat Apr 27, 2024 7:27 pm

N8TGQ wrote: ↑Sat Apr 27, 2024 6:54 pm I don't think you will see much difference when using short runs (around 25' or so). I have heard 316 is tougher, but it's also more expensive. I have a 20' length of 174 that's going on 5 years and about 100 outings. Never had any issues with it.

Good luck!

so... what's your pick, and why ?

Oh I saw you quoted me before you asked the question, so I thought you were asking me to tell you my choice again. The OP won't see any measurable difference between 174 and 316. He never asked about RG 58.