VHF/UHF RG-58/RG-6

Status
Not open for further replies.

Mattkuhar

Member
Joined
Oct 3, 2013
Messages
137
Location
New Haven County, CT
long story short here, everything ive ever seen online says 2way radios should have rg-58 used in the antenna system because its a 50 ohm cable and it matches better to the radio. but i was wondering if rg-6 can be used for an antenna for transmitting with. ive seen yes and no answers online and cant decide which to definitively use. id like to get a 1,000 ft spool for installs and dont want to buy it if i cant use it.
 

krokus

Member
Premium Subscriber
Joined
Jun 9, 2006
Messages
5,369
Location
Southeastern Michigan
Physically, yes you can use it. I would not suggest it, unless you are going to re-engineer the radio and antenna to be 75 Ohm, or utilize transformers at each end, to maintain proper impedance matching.

The impedance mismatch will cause high VSWR, if you just put the RG-6 into the system.

Sent via Tapatalk
 

davenlr

Member
Premium Subscriber
Joined
Jan 31, 2014
Messages
638
Location
North Little Rock, Ar
For transmitting you want to match the antenna impedance with the radio. In almost all cases of transmitting antennas, that is going to be 50 ohms.

I also would NOT use RG58 unless you are installing short runs (under 25') or mobiles. The loss on UHF will be astronomical with RG58.

RG6 will work, it will give you a slightly higher SWR, and resultant mismatch losses. It will work, but its not optimum to use for radio work, unless they are receive only, in which case, the mismatch wont be noticeable.

I am guessing you are wanting to save money, but coax is the last place you should try to save it. Get some LMR400 or equivalent for base station installs, otherwise all the money spent on antennas is going to go down the drain.
 

Mattkuhar

Member
Joined
Oct 3, 2013
Messages
137
Location
New Haven County, CT
nope, not trying to save money, actually posted on facebook about how 1,000ft of RG58 is only 360.00 and my cousin said i should use RG6 because RG58 is old lol. i pretty much knew it was an impedance match problem that would arise from using RG6, so i wasnt really going to even attempt it, lest i blow up my free TK-780 (not a chance). im only using the RG58 for mobile installs (gonna try doing installs for local people who want it done)
 

prcguy

Member
Joined
Jun 30, 2006
Messages
12,486
Location
So Cal - Richardson, TX - Tewksbury, MA
RG6 for low or medium power transmit is not a big deal, the match will be a little worse as mentioned and the loss is a little less than RG-58. Most mobile antennas come with about 18ft of coax so buying 1000ft of RG-58 anticipating installs for others doesn't sound very cost effective.
prcguy

nope, not trying to save money, actually posted on facebook about how 1,000ft of RG58 is only 360.00 and my cousin said i should use RG6 because RG58 is old lol. i pretty much knew it was an impedance match problem that would arise from using RG6, so i wasnt really going to even attempt it, lest i blow up my free TK-780 (not a chance). im only using the RG58 for mobile installs (gonna try doing installs for local people who want it done)
 

Mattkuhar

Member
Joined
Oct 3, 2013
Messages
137
Location
New Haven County, CT
what do you consider low to medium power? would i risk blowing a TK-780/880 from mismatch (40-50W Transmit)? would i risk blowing a bigger rig on the order of 110w Transmit using the RG6? just dont wanna blow my rigs up, thats why im being overly cautious with all this.
 

mmckenna

I really ♥ Ø
Joined
Jul 27, 2005
Messages
18,114
Location
Pt. Nemo
what do you consider low to medium power? would i risk blowing a TK-780/880 from mismatch (40-50W Transmit)? would i risk blowing a bigger rig on the order of 110w Transmit using the RG6? just dont wanna blow my rigs up, thats why im being overly cautious with all this.
Then get the right stuff.
$360 for a 1000 foot spool of RG-6 is a lot of money for a mediocre cable. Why not just put that money towards better cable? $360 will buy a lot of better quality cable. If you are going to be using this as a base set up, get yourself some 1/2" heliax or LMR-600 and call it done.

RG-6 is fine for a receiver, and it'll work OK as a cable for transmitting, but it's going to have more loss than a better grade cable. Since you likely don't really need 1000 feet, just get what you need. Put the money towards a higher grade cable.
 

kayn1n32008

ØÆSØ
Joined
Sep 20, 2008
Messages
6,325
Location
Sector 001
Wirelessly posted (Mozilla/5.0 (BlackBerry; U; BlackBerry 9900; en-US) AppleWebKit/534.11+ (KHTML, like Gecko) Version/7.1.0.1047 Mobile Safari/534.11+)

Mattkuhar said:
what do you consider low to medium power? would i risk blowing a TK-780/880 from mismatch (40-50W Transmit)? would i risk blowing a bigger rig on the order of 110w Transmit using the RG6? just dont wanna blow my rigs up, thats why im being overly cautious with all this.
Why would you knowingly present a missmatch to your transmitters? RG-58 is fime for mobile installs. I have *n M800 CDMA phone w/ a 800MHz BDA, a dual band BDA for my black berry, a TM-V71a, and a TK-760HG all use RG-58 for feedline. It is fine for short runs.
 

Mattkuhar

Member
Joined
Oct 3, 2013
Messages
137
Location
New Haven County, CT
@mmckenna - that was the price for 1000' of RG58, its for mobile use (parents wont let me do a base setup)

@kayn1n32008 - i didnt really want to present a mismatch. just wanted to make sure id be ok with RG58 for the mobile installs (my cousin knows squat about 2way) he was the one who said to just use RG6, but i was very hesitant on that knowing it would mismatch. so as long as im using it for short runs i will have no issues using RG58 in my mobiles, thats wonderful to know for sure.
 

mmckenna

I really ♥ Ø
Joined
Jul 27, 2005
Messages
18,114
Location
Pt. Nemo
So, if you don't mind me asking, why do you think you need 1000 feet of cable for mobile installs? Even installing in a full size pickup, I've never needed more than 10 to 15 feet.

Also, keep in mind that you will still need the antenna mounts and connectors to match the radios. Finding connectors to match the RG-6 isn't going to be as easy as finding connectors to match the RG-58.

If cable loss is really the concern, you can purchase NMO mounts with LMR-200, LMR-240 and other higher quality cables. Installation gets a bit harder with the stiffer cable, though.

Buying bulk, you can get NMO mounts for $15 or so with 17' of cable and a connector. Take that $360 and buy 24 of those. That's about 400 feet of RG-58 with the NMO already installed on the end and a connector. It's going to be hard to beat that deal buying the cable bulk, then adding the connectors and antenna mounts.
 

Mattkuhar

Member
Joined
Oct 3, 2013
Messages
137
Location
New Haven County, CT
i was going to buy the spool to have plenty on hand for doing installs for some friends/family. i did forget to factor in buying the NMO mounts though as well as connectors. i think i will definitely take that money and buy the pre fabbed assemblies and save the aggravation now though.
 

mmckenna

I really ♥ Ø
Joined
Jul 27, 2005
Messages
18,114
Location
Pt. Nemo
You can purchase the NMO mounts loose, with no cable. Really doesn't save you a whole lot unless you are doing a lot of installs and need custom cable lengths.

As it is, you can purchase NMO mounts with up to 25 feet of cable. Standard seems to be about 17 feet.

If you prefer, you can sometimes find them on e-bay cheaper. I've picked up a few unopened Motorola antenna/mount kits for $12 or so. Includes the NMO mount, cable, connector and an antenna. Kind of hard to beat.
 

krokus

Member
Premium Subscriber
Joined
Jun 9, 2006
Messages
5,369
Location
Southeastern Michigan
Check a local hamfest or swap meet. There are, typically, NMOs available. Just check to quality of the materials.

Sent via Tapatalk
 

N8DRC

Member
Joined
Jul 20, 2003
Messages
967
Location
Grass Lake
i was going to buy the spool to have plenty on hand for doing installs for some friends/family. i did forget to factor in buying the NMO mounts though as well as connectors. i think i will definitely take that money and buy the pre fabbed assemblies and save the aggravation now though.
That might be your best route, as mmckenna mentioned check around on ebay. I bought most of mine there brand new NMO with 17ft. coax $10.50 free priority shipping.

Most of all the ham swap meets I've been to they usually want way too much for used junk or an arm and a leg for new stuff.
 

prcguy

Member
Joined
Jun 30, 2006
Messages
12,486
Location
So Cal - Richardson, TX - Tewksbury, MA
I would have no problem running 500w through RG6 on HF. I would also have no concerns of blowing up any radio from the slight mismatch. That doesn't mean I use RG-6 for transmitting since I have enough 50 ohm coax of every kind to last me and everyone I know for the rest of my life.
prcguy


what do you consider low to medium power? would i risk blowing a TK-780/880 from mismatch (40-50W Transmit)? would i risk blowing a bigger rig on the order of 110w Transmit using the RG6? just dont wanna blow my rigs up, thats why im being overly cautious with all this.
 
Last edited:

Mattkuhar

Member
Joined
Oct 3, 2013
Messages
137
Location
New Haven County, CT
@N8DRC - i did just buy 3 NMO assemblies on ebay for i think 12 something each. just waiting to get the truck going before i drill the roof for antennas.

@prcguy - i wish i had tons of coax (of any kind) laying around my place lol.
 

davenlr

Member
Premium Subscriber
Joined
Jan 31, 2014
Messages
638
Location
North Little Rock, Ar
PRCGUY: My butternut all band HF antenna requires a matching section of 75 ohm coax. They recommend RG11, but since Im only using 100 watts, I was going to use RG6. Do you know where to find PL259 connector inserts that will fit the thicker RG6?
 

prcguy

Member
Joined
Jun 30, 2006
Messages
12,486
Location
So Cal - Richardson, TX - Tewksbury, MA
There is the UG-176 reducer to use RG-59 coax with PL-259s but I don't know of a reducer for RG-6. Here is a possible solution if your good with soldering: http://www.ad5x.com/images/Articles/Connectorizing RG6.pdf

I would also consider a high quality F compression connector for RG-6 then an F to PL-259 adapter.

BTW, I've installed a Butternut HV9 and I don't remember a 75ohm cable.
prcguy

PRCGUY: My butternut all band HF antenna requires a matching section of 75 ohm coax. They recommend RG11, but since Im only using 100 watts, I was going to use RG6. Do you know where to find PL259 connector inserts that will fit the thicker RG6?
 
Last edited:

davenlr

Member
Premium Subscriber
Joined
Jan 31, 2014
Messages
638
Location
North Little Rock, Ar
Never heard of transmitting through an F connector. The way the center conductor just uses a pressure fit Im not so sure the two small pieces of metal it pressure fits to inside the jack would handle 100W of power without getting hot.
 
Status
Not open for further replies.
Top