Home Antenna Sanity Check

[thisguyneedsabeer]

I think I'm finally going to pull the trigger and mount an antenna on the top of my town home so I can try to get some better quality across town (~3 miles) to a friend of mine. Being that our lovely city of Philadelphia is very dense with large buildings in the way and we both have roof access this seemed to be the best solution for now until we can find a suitable repeater location in between us.

• Antenna:Browning BR-6143
  • Browning BR-6143 UHF GMRS 450-470 MHz Base Antenna 3db Gain 5⁄8 wave 200 watt
• Cable: 50ft Times Microwave LMR400
  • Times Microwave LMR-400 - RG8/LMR-400/9913/RG213 Cable
• Connection 1: Times Microwave EZ-400-NF-X
  • Times Microwave EZ-400-NF-X N Female for LMR400, RG-8, 9913, 9913F7
• Connection 2: Times Microwave TC-400-BM-X
  • Times Microwave TC-400-BM-X BNC Male Connector for LMR-400, LMR-400UF, RG8, 9913
• Outdoor Mount:Philips Universal Adjustable TV Antenna Mount, Steel J-Mount for Attic Outdoor Roof Wall Installation, Weatherproof Mast Pole, Mounting Bracket and Hardware Included, Black, SDW1220/27
  • Amazon.com
• Misc: Dual Connector Installation (Heat Shrink)

Is there anything else I need to consider? I'm coming in around $230 with taxes and shipping.

My question is, is this all quality gear? Did I get the right connections? My radio inside terminates to BNC Female, so BNC male should be right or I have a big problem. I think I'm going to have to go directly into the siding, and then a PVC extension on the pole for some additional height so I basically mount it right outside my window, but also get above the roofline (I'm not a huge fan of ladders on roofs).

I'm hoping this will help our simplex communication. If this endeavor goes well, I'd like to repurpose the antenna and hook it up the Retevis RT97S/Midland Equivalent or perhaps a digital repeater system (obviously not GMRS), but that's down the line. I'm looking to learn and grow here. I'd like to not have to mount a variety of antennas, only one or two,

Anyway, rambling and off topic, any feedback is appreciated. Thanks!

 

[prcguy]

I would make the inside coax connector an N female then use a short LMR240 or LMR195 jumper to the radio. You don’t want to connect LMR400 directly to a radio and especially with BNC connectors. I would also recommend a higher gain antenna with 6dBd being the minimum goal. Do it once, do it right with no regrets.

If you are considering connecting a repeater in the future do not use LMR type coax due to passive inter modulation problems with the dissimilar metals used in the shield, and 50ft of LMR400 has way too much loss for use on a repeater. I try to keep UHF repeater feedline loss under .75dB and 50ft of LMR400 has about 1.6dB. You would be spending a lot of $$ on a repeater system and you don’t want to give up any performance to coax loss. You would also want that higher gain antenna on a repeater.

 

[thisguyneedsabeer]

I would make the inside coax connector an N female then use a short LMR240 or LMR195 jumper to the radio. You don’t want to connect LMR400 directly to a radio and especially with BNC connectors. I would also recommend a higher gain antenna with 6dBd being the minimum goal. Do it once, do it right with no regrets.

If you are considering connecting a repeater in the future do not use LMR type coax due to passive inter modulation problems with the dissimilar metals used in the shield, and 50ft of LMR400 has way too much loss for use on a repeater. I try to keep UHF repeater feedline loss under .75dB and 50ft of LMR400 has about 1.6dB. You would be spending a lot of $$ on a repeater system and you don’t want to give up any performance to coax loss. You would also want that higher gain antenna on a repeater.

Appreciate the detailed feedback, I will certainly change up my order and use a jumper. I like that idea, it makes things more universal in the end. Is there a specific antenna you might recommend in the 450-470 MHz preferably under $100? Would there be better type accepted cable that would be beneficial in both categories?

 

[prcguy]

-Appreciate the detailed feedback, I will certainly change up my order and use a jumper. I like that idea, it makes things more universal in the end. Is there a specific antenna you might recommend in the 450-470 MHz preferably under $100? Would there be better type accepted cable that would be beneficial in both categories?

Many companies make real 6dBd models like Laird and their model FG-4505 or even the Comet CA-712 series that is marketed for GMRS. I usually find them used or surplus much cheaper than retail. For full duplex repeater use you really need all copper feedline like Heliax or Messi/Paolomi makes an LMR equivalent in all copper. I run across lengths of Heliax all the time for free with connectors installed.

 

[thisguyneedsabeer]

Many companies make real 6dBd models like Laird and their model FG-4505 or even the Comet CA-712 series that is marketed for GMRS. I usually find them used or surplus much cheaper than retail. For full duplex repeater use you really need all copper feedline like Heliax or Messi/Paolomi makes an LMR equivalent in all copper. I run across lengths of Heliax all the time for free with connectors installed.

Yikes the new setup got expensive fairly quick, any tips on where I could potentially save or is this just the cost of doing it properly (which I'm fine with).

• Antenna: Comet CA-712EFC
• 50' Primary Cable (N Female-N Female): Times Microwave LMR-400
• N Female Connectors: Times Microwave EZ-400-NF-X
• 10' Jumper Cable (Inside, N Male-BNC): Times Microwave LMR-240
• N Male Connector: Times Microwave EZ-240-NMH-X
• BNC Connector: Times Microwave TC-240-BM-X
• Heatshrink (necessary?): ~$32.00

Total: $358.00 before taxes/shipping

 

[prcguy]

Yikes the new setup got expensive fairly quick, any tips on where I could potentially save or is this just the cost of doing it properly (which I'm fine with).

• Antenna: Comet CA-712EFC
• 50' Primary Cable (N Female-N Female): Times Microwave LMR-400
• N Female Connectors: Times Microwave EZ-400-NF-X
• 10' Jumper Cable (Inside, N Male-BNC): Times Microwave LMR-240
• N Male Connector: Times Microwave EZ-240-NMH-X
• BNC Connector: Times Microwave TC-240-BM-X
• Heatshrink (necessary?): ~$32.00

Total: $358.00 before taxes/shipping

Search for other ways to get the items. I don’t mean to brag but I’ve got hundreds of ft of LMR400, 500 and 600 for free, leftover from construction jobs. I get new in package Times EZ-400 connectors off eBay in the $8 range. A friend gave me a Comet CA-712 several months ago when he moved. I find lots of VHF and UHF repeater worthy antennas used very cheap at ham swap meets and free from friends. In fact one friend had so many commercial VHF/UHF/800/900 repeater antennas in his yard and couldn’t sell them all at swap meets so he posted them online, come get any and all for free. You don’t have to buy everything new for full retail. If you lived closer I would forward some of these deals on to you.

 

[thisguyneedsabeer]

Search for other ways to get the items. I don’t mean to brag but I’ve got hundreds of ft of LMR400, 500 and 600 for free, leftover from construction jobs. A friend gave me a Comet CA-712 several months ago when he moved. I find lots of VHF and UHF repeater worthy antennas used very cheap at ham swap meets and free from friends. I get new Times EZ-400 connectors off eBay in the $8 range. You don’t have to buy everything new for full retail. If you lived closer I would forward some of these deals on to you.

I apprecaite the sentiment just the same. This is the problem with not having any local friends in the hobby. I probably could save some money if I terminated the cables myself, I'd have to factor in the cost of tools, but then I would have tools, and a new skill.

 

[mmckenna]

Yikes the new setup got expensive fairly quick, any tips on where I could potentially save or is this just the cost of doing it properly (which I'm fine with).

Good stuff costs money. But the antenna system is the most important part of your station, and putting the investment in now will pay off in the long run. A lot of people new to the hobby tend blow all their money on a fancy radio, and then cut corners when it comes to the antenna system and then end up replacing it down the road.

Much cheaper to do it right the first time.

prcguy gave you some solid advice.

Heatshrink (necessary?): ~$32.00

No, not necessary, but it's a good addition.

New Times Microwave connectors usually come with it in the package. It acts as a strain relief, and generally makes it all look nice and professional.

It does not replace proper waterproofing of your outdoor connectors. I didn't see that mentioned in your parts list. You absolutely need to seal the outdoor connection at the antenna.
I'd add a roll of this to your parts list:

Sabre C20100712 - Weatherproofing

Sabre C20100712 Weatherproofing - Manufacturer: Sabre; Product Description: 1.5" x 15' Rapid Wrap Self-Amalgamating Tape. Designed to provide long term

theantennafarm.com

Getting water inside your connections will do a lot of damage. The extra $9 is well worth it.

I didn't see grounding/lightning protection included, either. Do you have a plan for that?

 

[thisguyneedsabeer]

It does not replace proper waterproofing of your outdoor connectors. I didn't see that mentioned in your parts list. You absolutely need to seal the outdoor connection at the antenna.

D'oh, and I already ordered. I'll give them a call in the morning to see if I can get that added before they ship.

I didn't see grounding/lightning protection included, either. Do you have a plan for that?

Of course I don't, because that would make sense. Forgive my ignorance, would that be something like this?

 

[mmckenna]

D'oh, and I already ordered. I'll give them a call in the morning to see if I can get that added before they ship.

If not, you can get it at Amazon. You might find it in the plumbing section of a hardware store for those "I'm not a plumber but I got a leak and I don't want to pay an professional" situations.

Of course I don't, because that would make sense. Forgive my ignorance, would that be something like this?

Well, you said you were in a Town Home, so I'm guessing someone else owns the physical building. They'd probably like it more better if you followed the National Electric Code. The code requires that the mast be grounded and there be some sort of entrance protector on the coax where it enters the building. The mast/protector need to be bonded to the building ground rod. That may get challenging. Might get expensive.
I'm not the grounding police, so you do what you want.

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

 

[thisguyneedsabeer]

Well, you said you were in a Town Home, so I'm guessing someone else owns the physical building.

We own our building, it's just a row home/town home setup. We're not standalone, I have attached neighbors on the left, and a gap in between us and the unit to the right. Could I just pick up something like this Sigma Electric ProConnex 41311 Ground Clamp 1-1/4 to 2-Inch, 1-Pack, Bronze (Amazon.com) and run it down the rear of my property into a ground spike with 10-12AWG?

If not, you can get it at Amazon. You might find it in the plumbing section of a hardware store for those "I'm not a plumber but I got a leak and I don't want to pay an professional" situations.

I do still have some: Nashua Tape 1 in. x 3.33 yd. Stretch and Seal Self-Fusing Silicone Tape in Black 1743082 - The Home Depot from a previous project. Silicone Tape should work just as well, right?

 

[mmckenna]

We own our building, it's just a row home/town home setup. We're not standalone, I have attached neighbors on the left, and a gap in between us and the unit to the right. Could I just pick up something like this Sigma Electric ProConnex 41311 Ground Clamp 1-1/4 to 2-Inch, 1-Pack, Bronze (Amazon.com) and run it down the rear of my property into a ground spike with 10-12AWG?

You can install a new 8' ground rod, however that new ground rod -must- be bonded to the existing home ground rod. You don't want two separate grounds.

I do still have some: Nashua Tape 1 in. x 3.33 yd. Stretch and Seal Self-Fusing Silicone Tape in Black 1743082 - The Home Depot from a previous project. Silicone Tape should work just as well, right?

That should work fine.

 

[03msc]

You can install a new 8' ground rod, however that new ground rod -must- be bonded to the existing home ground rod. You don't want two separate grounds.

I realize this could be considered hijacking the thread but it may be beneficial for some: what is the best way to do this if the added ground rod is on the opposite end of the house from the home ground rod?

 

[TGuelker]

Here is an eBay listing for a high quality arrestor with N connections

DC-2.4 GHz Replacement Gas Tube Lightning Arrestor | eBay

DC-2.4 GHz Replacement Gas Tube Lightning Arrestor.

www.ebay.com

The price is negotiable. I was able to get a couple bucks knocked off by selecting Make Offer.

I bought a couple spares just for the gas tube. The replacement gas tube is about $36.00 at https://www.polyphaser.com/surge-protector-rgt-kit-gastube

 

[WA0CBW]

03msc, the simple answer is you will need more wire. Can you move the antenna/mast ground closer to the main electrical panel ground?

 

[mmckenna]

I realize this could be considered hijacking the thread but it may be beneficial for some: what is the best way to do this if the added ground rod is on the opposite end of the house from the home ground rod?

Taking it all into consideration as part of the design is the way to do it. Placing the mast closer to where the existing ground rod is helps a lot. Not always possible with residential installs where keeping spouses/neighbors happy is the #1 goal.

Running suitable sized conductor between the new rod and the existing is required, as is installing periodic ground rods along the path, if I recall correctly.

Probably why many just skip it and hope for the best.

 

[03msc]

Here is an eBay listing for a high quality arrestor with N connections

DC-2.4 GHz Replacement Gas Tube Lightning Arrestor | eBay

DC-2.4 GHz Replacement Gas Tube Lightning Arrestor.

www.ebay.com

The price is negotiable. I was able to get a couple bucks knocked off by selecting Make Offer.

I bought a couple spares just for the gas tube. The replacement gas tube is about $36.00 at https://www.polyphaser.com/surge-protector-rgt-kit-gastube

Are those in the eBay listing legit or knock-offs? For that price it has me wondering...

 

[03msc]

Taking it all into consideration as part of the design is the way to do it. Placing the mast closer to where the existing ground rod is helps a lot. Not always possible with residential installs where keeping spouses/neighbors happy is the #1 goal.

Running suitable sized conductor between the new rod and the existing is required, as is installing periodic ground rods along the path, if I recall correctly.

Probably why many just skip it and hope for the best.

Would you say it's better to do that and have longer coax runs or run the ground?

In the instance I'm thinking of, antenna mast (and radio room, etc.) is on one end of the house while the house utility power meter and ground rod are on the other end (about 70' house width).

Doubt changes will be made at this point as far as location of masts, etc., but who knows.

 

[mmckenna]

Are those in the eBay listing legit or knock-offs? For that price it has me wondering...

Pretty easy to find Polyphasers at a good price if you shop around. For something safety related, I'd personally hate to rely on a cheap Chinese product just to save a few bucks.

 

[mmckenna]

Would you say it's better to do that and have longer coax runs or run the ground?

In the instance I'm thinking of, antenna mast (and radio room, etc.) is on one end of the house while the house utility power meter and ground rod are on the other end (about 70' house width).

Doubt changes will be made at this point as far as location of masts, etc., but who knows.

If one was to use the correctly spec'd coaxial cable, that's probably a good option. Good coax, properly routed to reduce length would be my choice.
I hate to cut corners when it comes to safety. Maybe I'll never have an issue with lightning at my home, but I'd prefer to not leave it to chance. I know some take a different approach, but I don't want to rely on luck.