Need help trying to make the best within my constraints

[Chubaca]

Im running a CB rig on my 98 4runner. Simple CB setup with 100watt amp, getting 1.5w DK and 15w swing on the radio and 100w PEP swing after the amp. Getting about 1.4-1.5 SWR across all channels. Originally I just wanted a simple setup for the trails/offroading but then I started getting interested in getting better performance out of it. Just having fun messing around with it.

Im happy with the radio and amp setup, but I think I need to work on my antenna setup. I have a 4ft firestik II off the back and I know its not the most optimal spot but I don't really have a lot to work with. Im wondering if you guys have any suggestions on improving things. Id really like to get 20-25 miles out of this, not sure if thats asking too much.


- I can't do a 102" whip
- I would consider going to a 5ft fiberglass
- Top of the roof is out of the question
- I would consider hood or front bumper mount if it would make a significant improvement


Any ideas? How bad do you think it is the way I have it? I haven't been able to make any good contacts to evaluate its current performance, I'm waiting on my buddy to get his setup together so we can do some testing. Ive received a lot of skip from all the way across the country, can't really tell how far I'm getting rx from locals though. Ive gotten good feedback on a couple radio checks but its always been from guys only a couple miles away.



Heres a couple pics, the top of the antenna is about 1.5-2ft above the top of the truck

 

[222DBFL]

I hate to say it, but your best performance is going to be on top of the roof. More metal under the antenna. A sirio pl5000 with a mag mount would work well if you don't want to drill. But a side mount isn't going to get the same results as mounting up top. More metal under the antenna the Better. Even if you took your current antenna and put it up top, it would make a difference. You should have no problem talkin 20 miles with a good antenna system and 100 watts. Do some research and you will find the roof is going to be the best spot for a good antenna system for the truck posted IMO.

 

[Nick23]

I have a 99 4Runner. I run a Predator 10-K on a single 5 inch magnet on the roof. With a Uniden 78ltw tuned by myself I can talk 35miles + mobile to base.

 

[Nick23]

If you are adamant about nothing on the roof, I would recommend moving your current mount above the tail light about 4 inches.

 

[binrat]

5' wilson silver load??

 

[Chubaca]

Would a 2ft roof antenna be better than a 5ft where it currently is? I really couldn't do much more than 2-3ft on the roof. I was looking into trying a 5ft Wilson silver load or everhardt sott though, think that would help a lot?

Would a hood mount be significantly better than what I have now?



I finally got to have a conversation with a couple hobbyists a little bit ago. I was getting out about 15 miles but could barely hear the guy that was 15 miles out. So I really need to improve my receive at least.

I also had a weird issue where my cb would randomly not transmit when I keyed down. It would show that it was txing but they couldn't hear me. I later took my quick disconnect off the antenna so I'm going to try again and see if that had anything to do with it. Could my amp be causing that?

 

[Nick23]

I think a little wil dead center of the roof would work the best for you. With mine I can easily hear stations 15 miles away and with 100 watts I'm sure you could talk that far. It would be a lot less of a hassle than the other options you mentioned too.

 

[M0GVZ]

The problem you have with the current installation is the body of the car is masking the antenna which is pretty much a no-no. To be honest I'm impressed you got the SWR that low and unfortunately the fact it is suggests quite a lossy installation and the losses will be due to the fact there's very little metal underneath it.

Compared to what you have installed now, even a magmount installation of a Sirio 5000 on the roof will perform better although a permanent mount should be the goal wherever possible and you can always plug the hole with a GPS antenna when you sell the car. Moving from where it is to a hard mount on the roof is worth roughly 6dB which is the equivalent of four times the signal but unlike using a linear it is both on transmit and receive. IT WOULD BE LIKE YOU CHANGING TO A 400W AMP WITH YOUR CURRENT INSTALLATION. I know you say you can't have a long antenna on the roof but the Sirio whip will take a lot of bending to the point I've tied one in a loop, put it in a suitcase for 24hrs when I took it on holiday and it was OK at the other end and again doing the same on the return journey. Some versions of the Sirio 5000 have a butterfly nut on so you can loosen it and lay the antenna down when you go in the garage. You could go for the Sirio 3000 which is shorter by about a foot and performs nearly as well. A 2-3ft antenna is a really bad idea though.

The next thing you need to look at is bonding. It'll not only increase performance but reduce noise as well. There's a good article here on how to do it and why you're doing it. I've done mine and I can park in the country with the engine running and have S0 noise. Remember to use flattened co-ax braid and not wire.

Bonding

There's lots to doing a mobile HF installation properly and it should take a good day to do but I can promise you from experience that it is worth it.

Everything you need to know is here:

www.k0bg.com

Install it to the standards on that website and you'll also be getting lots of "I can't believe you're mobile" comments as I do. I remember being parked in Nottingham (England) one day talking to a guy a few miles away and him asking what I was using which was a Maycom EM27 with 4 watts and a Sirio 3000 hard mounted on the roof. Apparently I was going over the top of some of the locals, some of whom were using 100W basically because they'd got poor antenna installations. A friend of mine who drove an 18 wheeler had his antenna effectively mounted similarly to yours and with 100W could barely make it 8 miles. We were having all on hearing him but he could hear us no problem. Its all in the antenna and how you install it.

 

[The Jerk]

Who tuned the radio? Sounds like they didn't work on the receive and the radio is essentially deaf.

Sent from my SAMSUNG-SM-G730A using Tapatalk

 

[M0GVZ]

Who tuned the radio? Sounds like they didn't work on the receive and the radio is essentially deaf.

The radio isn't deaf. Its where the antenna is installed. The installation is the equivalent of sitting the antenna on the ground without any groundplane under it and then putting a metal drum over the top. Your signal, what there is of it, isn't going to go anywhere.

 

[M0GVZ]

I finally got to have a conversation with a couple hobbyists a little bit ago. I was getting out about 15 miles but could barely hear the guy that was 15 miles out. So I really need to improve my receive at least.

I also had a weird issue where my cb would randomly not transmit when I keyed down. It would show that it was txing but they couldn't hear me. I later took my quick disconnect off the antenna so I'm going to try again and see if that had anything to do with it. Could my amp be causing that?

All of the above are symptoms caused by your antenna installation from not being able to be heard to not being able to hear people to the randomly not transmitting. The latter is caused by common mode current on the coax, which is basically RF on the outside of the coax where you don't want it, getting back to the amp plus the fact the antenna is so close to metal.

I can do more than 15 miles with 4 watts and be heard as clear as day. How yours is working is exactly how I'd expect it to work with the antenna being installed where it is.

 

[The Jerk]

Been the there, done that...there is still quite a bit of his antenna above the roof line. I think he has multiple issues, and the tune of the radio is likely a lot of it.

Sent from my SAMSUNG-SM-G730A using Tapatalk

 

[2RT307]

Would a 2ft roof antenna be better than a 5ft where it currently is? I really couldn't do much more than 2-3ft on the roof. I was looking into trying a 5ft Wilson silver load or everhardt sott though, think that would help a lot?

Would a hood mount be significantly better than what I have now?



I finally got to have a conversation with a couple hobbyists a little bit ago. I was getting out about 15 miles but could barely hear the guy that was 15 miles out. So I really need to improve my receive at least.

I also had a weird issue where my cb would randomly not transmit when I keyed down. It would show that it was txing but they couldn't hear me. I later took my quick disconnect off the antenna so I'm going to try again and see if that had anything to do with it. Could my amp be causing that?

I would absolutely NOT go with a short antenna. You could try a 5' antenna in the current location to get more antenna above the roof, as suggested by binrat with the Silverload. Good antenna, I've used them and had good results. You will probably see much better results on the hood mount, by getting more metal under the antenna. There are plenty of good strong mounts that will work for you using your existing antenna.

The Sirio antenna mentioned has gotten very good reviews here, and having one on the roof would work great. You can lower the mast with a simple twist of the lever on the antenna base, which could be an option for you when you need to go in the garage.

Not sure what the heck is going on with your transmit/no transmit issue. That's another thread.

73,
RT307

 

[w9cll]

Would a hood mount be significantly better than what I have now?

Anything, except a shorter antenna, would be better than what you have now.

 

[222DBFL]

Check out DNJ radio, and look up the sirio pl5000 performer and the 145 mag mount, even if you mounted it in the center of the hood it would perform better than your current setup IMO. But putting it on the roof is going to get you the best rx/tx. With the setup you have antenna not included, 15 miles should be a walk in the park with a good antenna system. Good coax jumpers as well. Put a sirio pl5000 performer with a mag mount as close to the center of the roof and you will indeed notice a difference IMO. Like is said, even the antenna you have now mounted on the roof would perform way better than where it's mounted now. Like said above, a 2 ft or 3 ft antenna isn't going to make much of a difference, you need some height to the antenna and some metal under it. Good luck with whatever you decide, and god bless.