The Road Ranger. 1997 SEMI

[Rick W]

Before I redid the radio and stuff for the fifth or sixth time, I stopped by a great ham radio shop that’s not too far from me when I was over in that area. I explained what I did and showed them these pictures and asked if they could tell what I was doing wrong.

The guy I know looked at it, and then he called over their antenna guru. Their consensus was that I had done a masterful job of not doing one thing wrong, but doing everything wrong, actually putting the antennas in the worst possible location to actually broadcast or receive considering the way I put the truck together.

Too much of the antenna is too close to the exhaust stack and (he said) probably the aluminum riser on my headache rack. And I had them mounted behind the cab which interferes with broadcasting and receiving from forward. They actually loved my installation and attention to detail, and said it was great, except that it would never work.

Then the third guy came out, and a customer, and they pretty much all laughed at me.

What was kind of interesting is that they both said that if I moved it to the side of the cab, and just raised them up about 12 inches, they would probably work perfect.

I researched the literature before I did all this, and my understanding was that they would “always“ broadcast forward and backward, but they could interfere with each other to the left or to the right. The amount of interference has to do with the distance between the antennas. Apparently I picked the best distance to make sure it’s the best interference in all directions.

Sooooo, I am going to move them around to the side, but not right now, there are so many other things to do first. But I don’t want to be without a radio, so I’m going to put a temporary up on top of the headache rack. I don’t want to be without the radio when I’m riding up and down the road with the long trailer.

it’ll just be another thing everybody can laugh at….

 

[Rick W]

Before I redid the radio and stuff for the fifth or sixth time, I stopped by a great ham radio shop that’s not too far from me when I was over in that area. I explained what I did and showed them these pictures and asked if they could tell what I was doing wrong.

View attachment 101803View attachment 101804

The guy I know looked at it, and then he called over their antenna guru. Their consensus was that I had done a masterful job of not doing one thing wrong, but doing everything wrong, actually putting the antennas in the worst possible location to actually broadcast or receive considering the way I put the truck together.

Too much of the antenna is too close to the exhaust stack and (he said) probably the aluminum riser on my headache rack. And I had them mounted behind the cab which interferes with broadcasting and receiving from forward. They actually loved my installation and attention to detail, and said it was great, except that it would never work.

Then the third guy came out, and a customer, and they pretty much all laughed at me.

View attachment 101806
What was kind of interesting is that they both said that if I moved it to the side of the cab, and just raised them up about 12 inches, they would probably work perfect.

I researched the literature before I did all this, and my understanding was that they would “always“ broadcast forward and backward, but they could interfere with each other to the left or to the right. The amount of interference has to do with the distance between the antennas. Apparently I picked the best distance to make sure it’s the best interference in all directions.

Sooooo, I am going to move them around to the side, but not right now, there are so many other things to do first. But I don’t want to be without a radio, so I’m going to put a temporary up on top of the headache rack. I don’t want to be without the radio when I’m riding up and down the road with the long trailer.

it’ll just be another thing everybody can laugh at….

afterthought, but the thing I found most shocking is, there was no way I could fix it with Rustoleum….

 

[RobbieD]

Don't stress over it.

If we did everything perfectly, every time, life would be boring as hell.

 

[sgtsandman]

I was wondering if that setup was going to work. From everything I’ve been told, a full size truck is the minimum size for dual antennas to work.

As far as antenna performance, height is might. The higher you can put it, the better. Thus why my antennas and the types of antennas are what they are.

The only antenna I compromised significantly on is the quad band on the fender. Since you can not get a spring loaded antenna for that type of antenna, I had to drop it down. Otherwise, trees would either bend the heck out of it or just plain rip it off.

 

[Curious Hound]

Radios at these frequencies are “line of sight”. In other words, everything interferes with the signal - the cab, the stacks, the headache rack, the other antenna, the full-size semi you’re driving next to. Etc. like Sandman said, height is might. Get them up high and unobstructed. Then there’s some kind of magic voodoo called ground plane that figures into it. Nobody really understands ground plane. It’s just a term they fling around to sound all technical and nerdy.

 

[sgtsandman]

Radios at these frequencies are “line of sight”. In other words, everything interferes with the signal - the cab, the stacks, the headache rack, the other antenna, the full-size semi you’re driving next to. Etc. like Sandman said, height is might. Get them up high and unobstructed. Then there’s some kind of magic voodoo called ground plane that figures into it. Nobody really understands ground plane. It’s just a term they fling around to sound all technical and nerdy.

The best I can describe ground plane is the antenna whip is only half of the antenna. The ground plain is the other half.

Then antenna placement gets thrown into the mix. If it’s placed in the middle of the roof, the output is omnidirectional. If put on the back corner, the strongest signal lobe is toward the opposite corner. Beyond that, I start to get lost. But anything other than the center of the roof is going to effect the transmission pattern of the antenna and create weak points and strong points that focus in different locations depending on where the antenna is mounted.

 

[Curious Hound]

The best I can describe ground plane is the antenna whip is only half of the antenna. The ground plain is the other half.

Then antenna placement gets thrown into the mix. If it’s placed in the middle of the roof, the output is omnidirectional. If put on the back corner, the strongest signal lobe is toward the opposite corner. Beyond that, I start to get lost. But anything other than the center of the roof is going to effect the transmission pattern of the antenna and create weak points and strong points that focus in different locations depending on where the antenna is mounted.

See? Magic voodoo that nobody understands.

 

[Rick W]

Amen, amen. My desire for this radio is just a little bit up and down the road as I’m driving, and the guy next to me to tell me if the trailer is doing anything funny. I knew it wasn’t an ideal set up, but again, I never expected it to not work at all. Again, from what I read, when you have dual antennas, you should be able to broadcast further perpendicular to the line between them, but maybe not along the line between them. Live and learn.

It’ll get worked out. If we love what we do, any job worth doing is worth doing twice.

 

[sgtsandman]

Most CB setups are good for only a few miles with a good setup since they only put out 4 watts. IIRC, 10 miles with a good radio and a 102” whip.

Now, if you get a radio with single side band, you can go quiet a good ways if atmospheric conditions are good. I heard a guy from Louisiana and another from Oklahoma talking to another in Maine on the way home from AOAA.

 

[Rick W]

Yeah, yeah, yeah, but you have to admit it looks cool! That’s like 2/3 of my mission!

Seriously, I just had the thought, troubleshooting in my mind, what if I just disconnect one antenna? That would tell me in a heartbeat how much of the problem is the antennas are too close and how much of the problem is the super structure around it.

 

[sgtsandman]

Yeah, yeah, yeah, but you have to admit it looks cool! That’s like 2/3 of my mission!

Seriously, I just had the thought, troubleshooting in my mind, what if I just disconnect one antenna? That would tell me in a heartbeat how much of the problem is the antennas are too close and how much of the problem is the super structure around it.

Sounds like solid troubleshooting to me. Do one thing at a time and see what fixes or partially fixes the problem and by how much.

 

[Rick W]

I have a couple of classic Cobra 148GTLs (SSB), one of which is a night watch sound tracker. Scuttlebutt says they’re the best SSBs ever made, but I really wouldn’t know. The SSB is fascinating, and I’ve had a couple of long-distance talks just sitting at the workbench in the garage, but that doesn’t do you much good when you’re just trying to talk up and down the road about weather and such, or talking to the guy next to you about the wheels flying off your trailer.

I’m planning on pulling the antenna coupling and just double checking that the coax isn’t grounded somewhere. Then I’ll try disconnecting one antenna and just see what that does, but my plan is to just quickly mount a single antenna in the center of the headache rack on a new coax while my interior is out. Then I’ll have some communications, and proceed on with all the different things I still want to do to the truck and trailer. It’s just sitting right now which really makes me crazy. I love working on them, but it really would be nice to actually drive one once in a while…..

 

[Rick W]

Last thought about ground planes, and I’m just making conversation here, I’ve been researching it most of the day.

When I was imprisoned with my health and handicaps, I set up a nice CB set up in my garage, mostly to test the radios, mostly to pass the time. I did my homework on how to set up the antenna, and which ones were good and not so good.

It turns out even for home use, a 102 inch whip on a 6 inch spring (total 108) is the best broadcast poll. That’s because it is exactly 1/4 wave length of the CB broadcast wave length. So I went in the shed of miracles and got one of my extras, and started with that.

Literature said to mount it up high enough so that you can run grounding guy wires, which act as the ground plane, at a 45° downward angle from the bottom of the spring. The guy wires themselves should not be grounded at the far end. They are attached to the ground at the antenna, but should terminate at the same length (108 inches) down the 45° angle. I accomplished this by simply putting a loop in the end of my copper wires at 108 inches, and then using a nylon cord to pull them taught to the mounting point.

I put my antenna about 18 inches off the side of the peak of the roof on my garage, on top of about a 6 foot PVC pole. I used a - wait for it – piece of scrap aluminum diamond plate to mount the antenna on the pole, drilling the four corners to run the four guy wires.

Three guy wires are apparently ideal, but they have to be perfectly spaced and equally angled, which can be hard to do with three wires. It’s very easy to get four wires aligned properly and spaced evenly, especially on a pitched roof, where the shingles are one giant graph paper.

I used a stranded 58 ohm coax cable down to my test bench ten feet below, routing the coax so I ended up with an 18 foot run (2×1/4 wave length). I also ran a double 10 gauge ground wire across the roof (under the guy wires), all the way to the soil/ground, and put in a new ground rod about 6 feet into the ground. Information said not to connect to the ground wire from the electrical panel, which can add noise to the system.

And let me say, holy cow, does that antenna work well!

From that research, and researching my current dilemma, I learned that (obviously) the signal emanates in all directions from the antenna, with the signal coming from the antenna being the strongest part of the signal. But the second the signal leaves the antenna, it reflects off of cotton pickin’ everything, whether it is metal or not, but especially metal. Regardless of the direction from the antenna, if there is reflected signal, unless it’s reflected at the exact right angle and distance, it will cause wave interference with the signal from the antenna, and diminish or defeat the effectiveness of the signal from the antenna. The reflections create noise upon the main signal, disorienting that signal.

The reason a flat surface on the roof of a vehicle is the best mobile set up is because there is nothing in the intended broadcast direction (horizontally outward) that will reflect off the antenna and interfere with the signal. Actually, the flat roof interferes, but it only interferes with the signal that would be going upward or downward, which is of no consequence on a vehicle. But that does actually still weaken the overall signal.

The 45° angle for the ground plane is ideal (apparently from literature), because when it reflects the antenna signal, it reflects it in the same direction, and in a complementary wave length to the signal from the antenna. So it can actually enhance the antenna, signal and distance rather than interfere with it.

If you think of looking down on the antenna from above, it’s the centerpoint in a broadcast circle. Anything that might reflect the signal is only going to reflect a small amount of the signal. The antenna broadcasts 360°, but only a few degrees of that would be reflected back by any single item. Apparently, my problem with The Road Ranger is that there’s so much junk around it that a large portion of the signal is being reflected back, and/or reflected at an angle and frequency that interferes with the travel of the signal. Also, the strongest interference would be from a matching broadcast point (the second antenna), and (I learned today) they should be a minimum of 6 feet apart, and then in additions of 3 feet, but ideally 9 foot (108”, quarter wave length) increments.

So, in my defense of my work so far, remember that the antenna is the strongest point of the signal, broadcasting the full 360°. I knew there would be interference from the reflection and the second antenna, but geometry told me I should still be able to broadcast forward and backward at a decent level. But my brain is a chemical engineering brain, and not an electrical engineering brain, and I underestimated the capacity of the interference.

Having chatted with these gentlemen this morning, I can also see where just moving the antennas to opposite sides of the outside of the cab, instead of the back of the cab, and moving them up just a little bit, will accomplish my goal of being able to broadcast forward and backward, and have some broadcasting ability to vehicles close by, but having very limited distance from side to side. That is now my ultimate plan, but I’m still going to put in a temporary for the time being.

If there are any questions, I will have office hours at 7 PM on Thursday….

It all sounds good in theory….

 

[Curious Hound]

Last thought about ground planes, and I’m just making conversation here, I’ve been researching it most of the day.

When I was imprisoned with my health and handicaps, I set up a nice CB set up in my garage, mostly to test the radios, mostly to pass the time. I did my homework on how to set up the antenna, and which ones were good and not so good.

It turns out even for home use, a 102 inch whip on a 6 inch spring (total 108) is the best broadcast poll. That’s because it is exactly 1/4 wave length of the CB broadcast wave length. So I went in the shed of miracles and got one of my extras, and started with that.

Literature said to mount it up high enough so that you can run grounding guy wires, which act as the ground plane, at a 45° downward angle from the bottom of the spring. The guy wires themselves should not be grounded at the far end. They are attached to the ground at the antenna, but should terminate at the same length (108 inches) down the 45° angle. I accomplished this by simply putting a loop in the end of my copper wires at 108 inches, and then using a nylon cord to pull them taught to the mounting point.

I put my antenna about 18 inches off the side of the peak of the roof on my garage, on top of about a 6 foot PVC pole. I used a - wait for it – piece of scrap aluminum diamond plate to mount the antenna on the pole, drilling the four corners to run the four guy wires.

Three guy wires are apparently ideal, but they have to be perfectly spaced and equally angled, which can be hard to do with three wires. It’s very easy to get four wires aligned properly and spaced evenly, especially on a pitched roof, where the shingles are one giant graph paper.

I used a stranded 58 ohm coax cable down to my test bench ten feet below, routing the coax so I ended up with an 18 foot run (2×1/4 wave length). I also ran a double 10 gauge ground wire across the roof (under the guy wires), all the way to the soil/ground, and put in a new ground rod about 6 feet into the ground. Information said not to connect to the ground wire from the electrical panel, which can add noise to the system.

And let me say, holy cow, does that antenna work well!

From that research, and researching my current dilemma, I learned that (obviously) the signal emanates in all directions from the antenna, with the signal coming from the antenna being the strongest part of the signal. But the second the signal leaves the antenna, it reflects off of cotton pickin’ everything, whether it is metal or not, but especially metal. Regardless of the direction from the antenna, if there is reflected signal, unless it’s reflected at the exact right angle and distance, it will cause wave interference with the signal from the antenna, and diminish or defeat the effectiveness of the signal from the antenna. The reflections create noise upon the main signal, disorienting that signal.

The reason a flat surface on the roof of a vehicle is the best mobile set up is because there is nothing in the intended broadcast direction (horizontally outward) that will reflect off the antenna and interfere with the signal. Actually, the flat roof interferes, but it only interferes with the signal that would be going upward or downward, which is of no consequence on a vehicle. But that does actually still weaken the overall signal.

The 45° angle for the ground plane is ideal (apparently from literature), because when it reflects the antenna signal, it reflects it in the same direction, and in a complementary wave length to the signal from the antenna. So it can actually enhance the antenna, signal and distance rather than interfere with it.

If you think of looking down on the antenna from above, it’s the centerpoint in a broadcast circle. Anything that might reflect the signal is only going to reflect a small amount of the signal. The antenna broadcasts 360°, but only a few degrees of that would be reflected back by any single item. Apparently, my problem with The Road Ranger is that there’s so much junk around it that a large portion of the signal is being reflected back, and/or reflected at an angle and frequency that interferes with the travel of the signal. Also, the strongest interference would be from a matching broadcast point (the second antenna), and (I learned today) they should be a minimum of 6 feet apart, and then in additions of 3 feet, but ideally 9 foot (108”, quarter wave length) increments.

So, in my defense of my work so far, remember that the antenna is the strongest point of the signal, broadcasting the full 360°. I knew there would be interference from the reflection and the second antenna, but geometry told me I should still be able to broadcast forward and backward at a decent level. But my brain is a chemical engineering brain, and not an electrical engineering brain, and I underestimated the capacity of the interference.

Having chatted with these gentlemen this morning, I can also see where just moving the antennas to opposite sides of the outside of the cab, instead of the back of the cab, and moving them up just a little bit, will accomplish my goal of being able to broadcast forward and backward, and have some broadcasting ability to vehicles close by, but having very limited distance from side to side. That is now my ultimate plan, but I’m still going to put in a temporary for the time being.

If there are any questions, I will have office hours at 7 PM on Thursday….

It all sounds good in theory….

Now you're getting it. And I am now obligated to say that you sound very technical and nerdy.

 

[Rick W]

Now you're getting it. And I am now obligated to say that you sound very technical and nerdy.

engineers always take that as a compliment!