What would be the best outdoors Discone antenna for 25-1300mhz? I use a Whistler 1040 radio scanner.

[KPMDWhistler]

I'm planning on mounting an outdoors antenna on a pole about 15-20 feet up and about 70ft from the radio scanner with RG59 coax, but i'm stuck on what discone 25-1300mhz antenna to get. I want something that's really good quality but not too expensive, less than or around $100-150. Also yeah I know I should be using RG58, but I have a spool of RG59 and some 50ohm connectors, hopefully it doesn't affect the quality too much.

 

[G7RUX]

Firstly, the impedance mismatch won’t cause an enormous loss. In theory you would be looking at around 0.2 dB at each end of the coax which is small and likely significantly less than the flat attenuation in the coaxial cable.

Regarding a suitable discone I would suggest seeing what your usual sellers can supply as none of these should be too expensive and should cover your intended range. The Icom units are decently made and should be within your budget if you wanted to go that way. Do beware that the antenna pattern of a discone tends to squint upwards as the frequency increases so high frequency performance might not be great. That said, your RG59 will make this worse as its performance above 500 MHz isn’t great. (Satellite TV coax is cheap and good performance in general if you don’t want too long a run.)

 

[KPMDWhistler]

Thanks for the advice! Yeah I usually stay below 470mhz, i'm thinking about the Tram 1410, gotta watch some YouTube videos about it first.

 

[GadgetGeek]

I'm very happy with the performance and build quality of the Diamond D-130.

 

[mmckenna]

I'm very happy with the performance and build quality of the Diamond D-130.

I scored a D-130N for free about 15 years ago. It's still up on the side of my house and is working fine. Kind of hard to beat those for an affordable/durable discone.

Ultimately, I think you'll be disappointed with that long a run of RG-59. If you are going to invest in a new antenna, give careful consideration to upgrading the coaxial cable, also. It's all part of the system, and expecting a big improvement in performance when using sub-par cable is going to be an issue.

 

[KPMDWhistler]

I scored a D-130N for free about 15 years ago. It's still up on the side of my house and is working fine. Kind of hard to beat those for an affordable/durable discone.

Ultimately, I think you'll be disappointed with that long a run of RG-59. If you are going to invest in a new antenna, give careful consideration to upgrading the coaxial cable, also. It's all part of the system, and expecting a big improvement in performance when using sub-par cable is going to be an issue.

Yeah I saw a video on YouTube stating that the Tram 1410 is horrible and that the D130 is much better. What type of cable would you suiggest for a long run from the N connector on the antenna to the BNC connector in my Whistler 1040?

 

[lu81fitter]

Yeah I saw a video on YouTube stating that the Tram 1410 is horrible and that the D130 is much better. What type of cable would you suiggest for a long run from the N connector on the antenna to the BNC connector in my Whistler 1040?

I don't have a discone. I have a Larsen tri-band with a ground plane kit, but I used about 65 feet of LMR 400 from the antenna to a 3 foot whip of LMR 240 to the radio. The 400 is stiff and I didn't want to put undo stress on the BNC on the back of my radio.

 

[GadgetGeek]

I'm using LMR400 too.

 

[mmckenna]

Yeah I saw a video on YouTube stating that the Tram 1410 is horrible and that the D130 is much better. What type of cable would you suiggest for a long run from the N connector on the antenna to the BNC connector in my Whistler 1040?

Which cable is right for you would really depend on your budget and how serious you want to get about this.

LMR-400 is a good entry level cable that will do what you want. It's reasonably priced if you shop around.
I'm running LMR-600 on mine at home, but that's mainly because I have access to a lot of it.
On a remote receiver I have at one of my high sites at work, I use 1/2" Heliax.

For hobby use, LMR-400 would be a good starting place. Ideally, you should get your radio and your antenna closer together. All coax has some amount of loss. That loss goes up with the cable length. It also goes up as the frequency increases.
If the systems you want to listen to are fairly close, then the LMR-400 or even RG-6 might be fine. If you are trying to do weak signal stuff, then you may want to run the LMR-600 or 1/2" Heliax. But that's going to be expensive.

And as lu81fitter said, you do not want to connect LMR-400 (or LMR-600, or 1/2" Heliax) directly to your radio. You want to use a short jumper of smaller, more flexible cable to make the connection. The stiff cable will easily break your antenna jack. The smaller cable will relieve the strain and prevent costly repairs.

I'd recommend getting LMR-400 with N connectors to match the antenna. Purchase a female N to BNC male cable to make the final connection to your radio.


And of course, you need to remember grounding of the antenna, as well as installing a lightning protector, if you want to do this to electrical code. If you are near KPMD, you'll deal with static from winds, and always the risk of lightning. You want to do the install right.

 

[KPMDWhistler]

Which cable is right for you would really depend on your budget and how serious you want to get about this.

LMR-400 is a good entry level cable that will do what you want. It's reasonably priced if you shop around.
I'm running LMR-600 on mine at home, but that's mainly because I have access to a lot of it.
On a remote receiver I have at one of my high sites at work, I use 1/2" Heliax.

For hobby use, LMR-400 would be a good starting place. Ideally, you should get your radio and your antenna closer together. All coax has some amount of loss. That loss goes up with the cable length. It also goes up as the frequency increases.
If the systems you want to listen to are fairly close, then the LMR-400 or even RG-6 might be fine. If you are trying to do weak signal stuff, then you may want to run the LMR-600 or 1/2" Heliax. But that's going to be expensive.

And as lu81fitter said, you do not want to connect LMR-400 (or LMR-600, or 1/2" Heliax) directly to your radio. You want to use a short jumper of smaller, more flexible cable to make the connection. The stiff cable will easily break your antenna jack. The smaller cable will relieve the strain and prevent costly repairs.

I'd recommend getting LMR-400 with N connectors to match the antenna. Purchase a female N to BNC male cable to make the final connection to your radio.


And of course, you need to remember grounding of the antenna, as well as installing a lightning protector, if you want to do this to electrical code. If you are near KPMD, you'll deal with static from winds, and always the risk of lightning. You want to do the install right.

Wow okay, that's a lot of useful information. Thanks for the tips, I'll definitely be sure to follow you and lu81fitters advice! I'm going to have the antenna be on a metal pole just peaking over a very large bush so it's kinda hidden, and there is two very large pine trees over the bush. Would I still need lightning protection of there's two pine trees so close to it? Also, would I still have to ground it even though it would be bolted to a long pipe of metal conduit or aluminum pole that's stuck directly in the ground?

 

[mmckenna]

National Electric Code says it has to be grounded/bonded to the same ground as your homes electrical panel, and you do want a lightning protection device where the coax enters the home.

 

[KPMDWhistler]

National Electric Code says it has to be grounded/bonded to the same ground as your homes electrical panel, and you do want a lightning protection device where the coax enters the home.

I have to connect it my my houses electrical panel? like the circuit breaker? I mean its just going to be a receiving antenna for a radio scanner, I don't understand why I can just ground it right where it is.

 

[mmckenna]

I have to connect it my my houses electrical panel? like the circuit breaker? I mean its just going to be a receiving antenna for a radio scanner, I don't understand why I can just ground it right where it is.

No, National Electric code requires that the antenna mast ground and the lightning protection device be properly grounded. If you can do that safely to your existing ground rod, like your antenna/coax entry is at the same place that the existing ground rod is, you can use the same one. If the mast/coax entry is somewhere else on your home, you need to install a new ground rod and that new ground rod M-U-S-T be bonded to the existing one.

That's if you want to do it to code.

https://www.mikeholt.com/instructor2/img/product/pdf/17LED-1498-sample.pdf

 

[surfacemount]

I have to connect it my my houses electrical panel? like the circuit breaker? I mean its just going to be a receiving antenna for a radio scanner, I don't understand why I can just ground it right where it is.

No.

To the same grounding point, you really should.

Receivers are very touchy, and static absolutely will pop a front end. Others can explain it better, but you might be able to pull the antenna pole to ground, but you still want some grounding in the shack local to the appliance, too.

If you are using an appliance that is plugged into house power wiring, and it is connected to an outside antenna via a wire, you have created a thing. You want all the grounds to be at the same potential. IF there is even a few feet from where the pole grounds and the house grounds, and there is a nearby lightning strike, there will be induced current (electricity), and your system will suffer. (this is called 'voltage gradient', and it's how people get killed walking around downed power lines.) This is also how ground loops occur, and can be pain in the balls to run down.

Also, if your antenna is on an isolated ground, and you are using a battery powered appliance inside the house, if there is RF interference inside the house or outside the house... your system will suffer. And, there is *always* RFI/EMI. Always.


Lastly, if you live in an area where there are insurance or code inspections, or you have a fire or something else terrible happens, and they see you didn't do your thing 'right'... (noticing a pattern here?)