Btech 50 Watt Radio Reception Issues with Tram 1181 Antenna (MNO Mount)

[WSBV575]

Hey everyone, I'm hoping to get some help with a bit of a head-scratcher. I recently installed a Btech 50 watt radio with a Tram 1181 antenna on an MNO mount.

I've double-checked that everything is grounded properly, and while the radio transmits just fine, the reception is absolutely plagued with noise. Here's the weird part: if I completely remove the antenna from the MNO mount (but leave the mount itself attached to the bracket), reception improves dramatically! It's still not perfect, but it's a world of difference compared to having the antenna screwed on normally. In its normal configuration, the reception quality is worse than my handheld radio, and the range is definitely suffering too. I'm at a loss here. Any ideas what could be causing this? I am thinking antenna but I am not sure. 

[WRWE456]

Hello and welcome! Have you tried it outside of that concrete block walled garage? Is it a GMRS radio or ham Radio? The antenna is a duel band ham antenna but does cover the GMRS range. You are testing with VHF NOAA weather channels, Have you tested on GMRS?

[WRWE456]

What I'm asking is to give more details on your setup and testing procedures. Need more info.

[WSBV575]

10 minutes ago, WRWE456 said:

Hello and welcome! Have you tried it outside of that concrete block walled garage? Is it a GMRS radio or ham Radio? The antenna is a duel band ham antenna but does cover the GMRS range. You are testing with VHF NOAA weather channels, Have you tested on GMRS?

So, the symptoms on that video are the same on 147.1350, 462.650.

I have tried it in an open field on 160 acres and in a parking garage (places I tend to be) the antenna makes the issue worse. The unit works well without an antenna (but I think that may not be normal). The radio is a GMRS and HAM. 

[WSAM454]

Have you checked transmit SWR with the antenna outside, in the clear?   You are removing the antenna 'whip'  but not its entire NMO mount; could there be a problem with the cable or the actual NMO mount?   (either the antenna's mount or the car's mount.)  Can you try another NMO mount antenna to see if it may be in the feedline or the mount itself?

[WSBV575]

19 minutes ago, WSAM454 said:

Have you checked transmit SWR with the antenna outside, in the clear?   You are removing the antenna 'whip'  but not its entire NMO mount; could there be a problem with the cable or the actual NMO mount?   (either the antenna's mount or the car's mount.)  Can you try another NMO mount antenna to see if it may be in the feedline or the mount itself?

See, this is what I am wondering. I don't have another antenna to test, I will need to buy one. I suspect the cable is good since the radio workers without noise or static when no antenna is present. 

How do I test SWR?

[WSAM454]

Actually, it could be the cable, since I have found that sometimes a radio will receive well UNTIL the outer part of the PL-259 connector touches the barrel of the SO-239. 

To test SWR, you need a device.   The most common is an SWR/Wattmeter such as the very popular and relatively inexpensive one that usually goes by the name Surecom SW-102 UV.   (about $60 on Amazon) It must be a meter that will work on the GMRs freqs, which are referred to as UHF.     If you are not very technically inclined, then I would suggest only the first 6 or so posts in this discussion, and don't get carried away with the rest of the 2 pages!  

https://forums.mygmrs.com/topic/7312-budget-friendly-swr-meter/

If you find the SWR is very high, that may point to a cable/mount problem.

 

If you can borrow another antenna to test the mount, that would also help give more information. 

 

Looking more closely at your video, are you sure that is an NMO mount?   It looks like your antenna is screwing into an SMA connector, like is used on the top of a hand held radio.  Can you remove the entire black part  (down to the black rubber washer)  and still have something that looks like this mounted to the metal bracket?

[WSBV575]

That video is me only removing the whip, the copper base is MNO. Looks like your photo. 

[WRWE456]

You could do a test. Get an adapter for the hand held to the antenna in the truck. if the the problem is still there with the hand held then it is the antenna or cable, if it is gone then the radio is likely defective.

[WSBV575]

3 minutes ago, WRWE456 said:

You could do a test. Get an adapter for the hand held to the antenna in the truck. if the the problem is still there with the hand held then it is the antenna or cable, if it is gone then the radio is likely defective.

I used a unit of my friends, just plugged his into my cables. Worked great, no noise, no popping sounds. Returning tomorrow for refund. Thank you for the suggestions !

[WRWE456]

Alright great! Glad we could help. The quality control on inexpensive gear can be hit or miss. Good luck!

[WRXB215]

8 hours ago, WRWE456 said:

The quality control on inexpensive gear can be hit or miss.

Aint that the truth. I don't have very many radios but I've seen quite the interesting difference in the ones I have.

[WRWE456]

I see on RR forum you asked for a GMRS mobile radio recommendation. You should ask that here.

For GMRS specific certified radios (which your B-Tech is not). Wouxun is the current leader. The KG-1000G+ and the KG-XS20G+ are the top radios as far as many are concerned. They are however very feature rich and are geared toward what you might call "power users"(or radio dorks) who want all those features. They are well built and perform very well. They are not rebranded or sold under other names (that I have ever seen) unlike most other China brands. Buy Two Way Radios is the place to get them. They are a sponsor of this site. They are the importers and work with Wouxun to design the radios for the American market.

Midland is geared toward and popular with folks that just want a more basic radio that is very easy to use and simple to operate.

All GMRS radios are made in China including Midland.

Some will recommend buying a used commercial radio but there is a lot to learn to use them. Maybe after you become a more seasoned radio operator you could look into that option.

Just my 2 cents.