SDR Antenna & Recption

[larrylwill]

Sorry if dumb question.
If I build a 1/4 wave ground plane antenna using a Type N chassis mount connector and RG6 or RG59 cable how do I get from the female N to the coax cable then from the coax to the SDR male connector for the sdr radio.
Yes I know the RG6 and RG59 is 75 ohm, Maybe I need to order some RG8?
There's lots of info out there but little of the really basic stuff that I can find.
I had a one man business since 86 in my shop testing IC's. I have lots of computer junk and other electronics but nothing for being a ham.
kb5udf, hopefully.

 

[mmckenna]

If you are not limited by budget, you'd be better off getting a suitable coaxial cable and connectors to meet your needs.

Yes, 75Ω cable will work just fine for receiving.
Yes, you can get N connectors that will work with 75Ω cable.
But you can spend a lot of time and effort chasing this stuff down all to save a few dollars.

Sometimes a suitable length of good coax is worth a lot. Order what you need once and be done with it.
You can have custom length/connector'd cables made here:

Custom Coax Cable Assemblies - 50ohm Radio | Antenna Farm

Shop custom 50ohm radio coax cable assemblies at The Antenna Farm using our Cable Builder. Enter cable length, select your connectors and installation options.

theantennafarm.com

 

[sunwave]

Tram isn't a great brand. They are Chinese knock off products. Fine for hobby use, but you can do better.

First of all My Tram 1089 is doing great. Second of all Tram-Browning is not chinese and headquarters are in Edmond, Oklahoma. Petra subsidiary.

https://www.petra.com/products/automotive-and-marine/automotive-electronics/cb-radios-and-scanners/scanner-antennas/_item/tram-1089-sma-scanner-mini-magnet-antenna-vhf-uhf-800mhz-1-300mhz-with-sma-male-connector.html

 

[saioke]

First of all My Tram 1089 is doing great. Second of all Tram-Browning is not chinese and headquarters are in Edmond, Oklahoma. Petra subsidiary.

https://www.petra.com/products/automotive-and-marine/automotive-electronics/cb-radios-and-scanners/scanner-antennas/_item/tram-1089-sma-scanner-mini-magnet-antenna-vhf-uhf-800mhz-1-300mhz-with-sma-male-connector.html

I also have a 1089 and it's pretty decent, especially outside. I took mine down from my roof though because it was starting to rust and I was worried about my roof rusting as well. Currently using it indoors for local DMR. It does okay for 700/800 P25 but a yagi helps the most in my situation.

That being said, I also have a Tram 1410 Discone and I regretted buying it. It seems to do well across the board, but doesn't do them particularly well. The tram 1089 will pick up local DMR in the 400mhz range better than the discone, and I struggle to even get a signal to local P25 sites at all. I'm not sure if the Diamond would be any better, but I can't really blame Tram when this is just how Discones seem to be.

What the discone really shines at, is airband. Aircraft are clear as a bell. Oh, and FM stations. I can pick up FM 40 miles away with the discone. That's way better reception than any other FM antenna I've used in the past. Still, I'd sell it if I can muster up some courage to get it back off of my roof. I can't handle heights lol.

 

[I_Am_Infinite]

Sorry if dumb question.
If I build a 1/4 wave ground plane antenna using a Type N chassis mount connector and RG6 or RG59 cable how do I get from the female N to the coax cable then from the coax to the SDR male connector for the sdr radio.
Yes I know the RG6 and RG59 is 75 ohm, Maybe I need to order some RG8?
There's lots of info out there but little of the really basic stuff that I can find.
I had a one man business since 86 in my shop testing IC's. I have lots of computer junk and other electronics but nothing for being a ham.
kb5udf, hopefully.

LMR 240 wud be a good coax. Rg6 can work. There is kmr 240 on Amazon some like it others don't.

 

[dave3825]

Second of all Tram-Browning is not chinese and headquarters are in Edmond, Oklahoma. Petra subsidiary.

Petra is only a distributor. They distribute over 500 brands of merch.

From the link you posted, it states Country of Origin is Taiwan. Either way, its from overseas.

 

[mmckenna]

First of all My Tram 1089 is doing great. Second of all Tram-Browning is not chinese and headquarters are in Edmond, Oklahoma. Petra subsidiary.

That's great.

The small office in Edmond OK is just the US office. The Tram/Browning products are absolutely overseas.

If they work for you, then awesome. Let me know when it's been up there nearly 20 years. Meantime, $20 extra for a proven brand is worth it for some, especially if that saves climbing up on the roof.

 

[larrylwill]

Didn't mean to start a disagreement.
Since I'm 80, 20 years would outlive me.

 

[mmckenna]

Didn't mean to start a disagreement.
Since I'm 80, 20 years would outlive me.

It's all good. You decide what works for you.
I've always found that since the antenna system is the most important part of any radio system, investing there is always a good plan. A quality antenna and feedline will pay for itself in short order.

If the lower cost antenna makes more financial sense for you, then go with that. Truth is, all antennas with the same design are going to work similarly. Where the difference starts to show up is in the build quality and materials. Those will start to show up over time as reduced performance/failures.

I've disassembled some old Tram/Browning products over the years and compared them to name brand products. You can find those if you search back through my posts. The cost savings for the Tram/Browning products comes from lower quality products. For many hobbyists, there is an acceptable trade off between quality and cost. After all, it's a hobby and should be something that doesn't break the bank.

 

[larrylwill]

Last question: I think this the bundle I need to build a ground plane antenna and hook it to my SRD. What do you think?

3 Pcs UHF Female Jack SO-239 Bulkhead Panel Chassis 4-Hole Panel Mount Solder Connector

Ham Radio Coax Cable 50 Ohm, RG58 Coaxial Cable 50FT, ​

PL259 Male to Male Coax + UHF SO239 Female to SMA/UHF/BNC Adapter 4-Pack​

2 Pack 12 Inch UHF SO239 Female PL259 to SMA Male Plug Crimp Adapter RG316 Cable Jumper Pigtail 30cm​

​

 

[mmckenna]

Those will work for making a basic 1/4 wave ground plane.

 

[larrylwill]

thank you

 

[dave3825]

Didn't mean to start a disagreement.

Don’t swear it Larry. A claim was made, and the claim was corrected.

I have a tram discone and not fond of it for anything other than air band. Sucks on 7/8/900 MHz that are not in my immediate area.

Last question: I think this the bundle I need to build a ground plane antenna and hook it to my SRD. What do you think?

I made one of these a while back and went with Tri-Band. Worked pretty decent.

 

[larrylwill]

I will try it, waiting on connectors.
thank you.

 

[saioke]

Wouldn't mind making one of those myself. There's only 2 radials for the ground plane though? Thought there was 4? Guessing you mount them in the center instead of using the pre-drilled holes on the base like below?

Or are there supposed to be 4 ground radials mounted at those holes?

 

[larrylwill]

I never noticed that. I will try it with 4. Ordered the connectors today. Same as your picture.

 

[mmckenna]

Wouldn't mind making one of those myself. There's only 2 radials for the ground plane though? Thought there was 4?

Minimum 3, I'd do 4. Don't go by the drawing, they are just showing a broadside view.

Guessing you mount them in the center instead of using the pre-drilled holes on the base like below?

Use the predrilled holes and something like #6 hardware. You might be able to solder them, but you've got to have a really hot/big soldering iron and the skills to use it and not melt the insulator.

 

[dave3825]

Not the best set of directions, but yes, 4 radials is what I did.

 

[saioke]

Thanks, they seem easy enough to make. Be an interesting project. I think it would be easier to bolt the radials instead of soldering for sure. I have an old soldering gun but I think that would be too hot and overkill. Would definitely melt the insulator with that beast lol.

I do wonder how much gain these can put out.

 

[mmckenna]

I do wonder how much gain these can put out.

1/4 wave antennas are 0dB gain.
But the benefit is that they are quite broad banded.