Antenna Position

[WSDS325]

Ok, so I cant figure this out. There is a repeater in my area and I've got all the tones correct and can hear it very clearly (every hour it automates the time and weather,) but it cant hear me. I'm using a 10W handheld connected to an antenna on my roof.

So, I use a 2x4 piece of wood to extend my antenna like 4 extra feet. Now I can reach the repeater and people can hear me but it's not super clear, also, now I can no longer hear the repeater clearly at all. I miss like every other word of the time and weather report because of static.

I then remove the 2x4 and put the antenna back to where it was, and the report is crystal clear, but still i'm unable to communicate with it.

 

What is going on? why can i get better reception when the antenna is lower?

[WRQD922]

Couple of questions. What antenna are you working with ? Type of coax ? How far away is the repeater ? 

[Guest]

Also what hand held are you using?   Sound like a ground plane issue.  I’d also love to know what antenna 

[dosw]

And along with what type of antenna are you using, is what are its ground plane needs, and what is your ground plane?

[WSDS325]

The antenna is a Tram 1477 Pre-Tuned 144MHz–148MHz VHF/430MHz–460MHz UHF Amateur Dual-Band Base Antenna. I got it on amazon. It does have the 3 metal ground plane probes at the bottom of it.

The Radio is a TIDRADIO TD-H8

The type of coax cable is just what was installed with the old Direct TV satellite dish on my roof. I just cut it and used it because it already ran into the house to my desk. 

 

repeater is about 15 miles away from me to the North West, however there are two other repeaters that are further than that (about 20 miles) that are more to the north.

 

 

[Borage257]

If you are using your satellite dish coax, you have an impedance mismatch. You are losing a TON of signal by using the wrong stuff. Screaming into a pillow in the garage expecting your friend a room or two over to hear you.

 

Get some 50ohm coax, LMR400 or KMR400

[WSDS325]

28 minutes ago, WSDS325 said:

The antenna is a Tram 1477 Pre-Tuned 144MHz–148MHz VHF/430MHz–460MHz UHF Amateur Dual-Band Base Antenna. I got it on amazon. It does have the 3 metal ground plane probes at the bottom of it.

The Radio is a TIDRADIO TD-H8

The type of coax cable is just what was installed with the old Direct TV satellite dish on my roof. I just cut it and used it because it already ran into the house to my desk. 

 

repeater is about 15 miles away from me to the North West, however there are two other repeaters that are further than that (about 20 miles) that are more to the north.

 

 

I'd also like to add a photo for reference. This is how I have it currently set up. this is without the 4' 2x4. I would think it would be a ground plane issue too, but i just don't know how to fix it.

[Borage257]

You can get 5ft antenna pole segments at Lowe’s/Home Depot that can be attached where the antenna is now.

 

Get the antenna above the dish and get good coax

 

The segments have a swaged end, so if the dish is mounted on a pole, you can simply set the segment into the dish mount. 

[dosw]

That antenna has ground plane radials.

 

The dish *could* be interacting in some way... well, not could, is. But it's hard to know what the net effect is.

 

The biggest issue would be that coax. It's 75ohm, and very lossy. Probably RG6 or RG59. And given its age, could even have UV and water deterioration. Just moving the cable a little could change its attenuation a lot. Until you're running reasonable cable it's pretty hard to proceed to the next step of fine tuning the antenna placement.

[WRYZ926]

I have to agree with what everyone has said about the coax. TV/Satellite coax cable is the wrong stuff for radio antennas. You want coax rated at 50 Ohms. LMR400 or equivalent is what you want for UHF frequencies to include GMRS.

Plus your antenna is not tuned for GMRS frequencies either. GMRS is 462 MHz and 467 MHz. The antenna may or may not have decent SWR for GMRS.

I also see the dish causing issues with your vertical antenna. Either raise the antenna above the dish or remove the dish from the mount (if not in use).

[WRQD922]

I have used the Tram 1477 and it will tune up fine for GMRS. Like everyone has said above, get the tram a good five ft. Above the dish and purchase some decent 400 coax and your problems should disappear. Good luck. Don’t hesitate to ask more questions if you have problems going forward.