one in a million shot

[niceguy71]

I know the guys here dislike magnet mount antenna's. we all like something different... that's why we have red cars and blue cars because we all like something different.... ( all my vehicles are red)

I hear it said the coax gets damaged in the windows or doors on mag mounts........ I have my coax sitting on the roof dropped into the bed of the truck and into the cab..... it doesn't move in the wind so it should be perfectly safe for years.

I was taking a 175 pound water heater to the scrap metal yard, I have a very soft rubber mat in the back of my truck, and nothing moves on that mat! .... well the traffic backed up fast and the cars and trucks in front of me, all had to lock them up and swerve around the vehicles in front of them going into the breakdown lane.... I stepped on my brakes hard and stopped with plenty of room.... but that heavy heater slid into the bed.... I thought it was odd I didn't hear a metal to metal clank???? I heard a light thud.... but it was softer than it should have been????
so I got to the yard and saw the coax took the brunt of the impact.
I ran my fingers up and down the coax and it felt perfectly normal, that was a few days ago....

I checked my SWR on my little Chinese SWR meter that is on the side of my CB and it says my SWR is 1.2 .... so I figured good no damage?
the last couple days I have not had one contact??? I normally can get someone on Lower Side Band.... I heard a few people but could not contact them... but that's the way it works some days...... tonight I went to the post office and heard no one on our local channel 27??? ( I heard skip ... whistles.... Roger Beeps hundreds of miles away...but nothing local...... I called out several times... never got anyone... sometimes no one is there....... I tried radio checks on 19 but didn't hear anyone local on it so I wasn't expecting a radio check...
but now I am wondering if I did get some damage to the coax I can't see.
this weekend I'll hook up my cam-Corder pointed at the base station and go for a ride and see if I can get my usual range
but if that coax got damaged it's really a million to one shot.... and I won't be very happy.... they discontinued the Tram 3500, I used to always be able to buy one for around $30 bucks, not sure I want to pay more than $50 bucks,...... maybe it's time to try the Stryker SAR-10.

I think it must just be a flute not getting any contacts.... and I'll get contacts next time I drive the truck... but I guess the coax could be damaged?
so I finally see one disadvantage to the magnetic mount CB antenna.

 

[SmileySixguns]

I would pull the cable back out of the cab, then run it down between the cab and the bed and then back into the cab

 

[SmileySixguns]

And if you're careful, you can push that air vent that's in the back wall of the cab out of the back of the cab, rotate it slightly, and then pull it into the cab. This will give your hands much more room to work with to grab the cable end. Putting it all back in is just the reverse.

 

[niceguy71]

I would pull the cable back out of the cab, then run it down between the cab and the bed and then back into the cab

That wouldn't work for me.
I run my truck through the car wash once a week.... Keeps the truck looking brand spanking new.

When I go through the car wash I go in the bed and take the magnet off the roof and then place it in the bed on its side..... I stick the magnet to the wall of the bed so it's laying in its side with the magnet attached to the front wall of the bed.......
The car wash has huge brushes that go over the roof then go against the back glass of the pick up.... The brushes are wider than the truck so when the brushes get to the top of the bed they can't go lower and all my coax is in the bed where the brushes can't grab it... It's worked perfectly for over a year ..

.. If the coax was between the cab and the bed and I took the antenna off the roof to set it in the bed.... The coax would now be sitting on the top of the bed and the brushes would certainly grab it.....
My system is working great ... I just never thought anything would slide forward on me .... NOTHING has slid in that truck for 13 years..... And even if it did ... Out of a 5 foot wide bed wall it has to hit a 1/4 inch coax.... So it just happened to be a one in a million shot.

If you go to this video at 2:40 you will see how the antenna and coax is completely protected from the car wash
Video of my coax protected from car wash at 2:40

 

[RFI-EMI-GUY]

Ohm the cable out for continuity, open circuit and/or shorts.

 

[niceguy71]

Ohm the cable out for continuity, open circuit and/or shorts.

The Tram 3500 when you do a continuity check from center pin to threaded barrel will always show a direct short
I sent the first one back as defective and the replacement did the same thing so I called Tram, they said that's the way they work and not to worry about it. I actually wrote Erik from Far Point Farms and asked him to check his as I knew his worked fantastic from all his test videos .... He checked his . . Yup dead short... They all show that on a ohm meter but work perfectly.
Great idea though, thank you

Where I can't feel a flat spot and the swr is 1.2 I think it may be ok and I just need to spend some more time trying to make a contact.
Just weird I've not had one contact for two days. I'll hook up my cam corder ... I don't want to take a chance on hurting my radio

 

[robertwbob]

The Tram 3500 when you do a continuity check from center pin to threaded barrel will always show a direct short
I sent the first one back as defective and the replacement did the same thing so I called Tram, they said that's the way they work and not to worry about it. I actually wrote Erik from Far Point Farms and asked him to check his as I knew his worked fantastic from all his test videos .... He checked his . . Yup dead short... They all show that on a ohm meter but work perfectly.
Great idea though, thank you

Where I can't feel a flat spot and the swr is 1.2 I think it may be ok and I just need to spend some more time trying to make a contact.
Just weird I've not had one contact for two days. I'll hook up my cam corder ... I don't want to take a chance on hurting my radio

They got a ceramic disc soldered from center load to ground side of coax .i discovered that a few years back A99 same way even my sirio 2008 shows continuality

 

[FKimble]

Is the coax connection to the radio internal and not a screw on/off connector?

Frank

 

[niceguy71]

I've seen a antenna coax that doesn't screw / unscrew from the radio .. but to answer your question the Tram 3500 is an antenna that can be screwed to a CB..... So yes it can be unscrewed.

 

[FKimble]

Coax to radio, not coax to antenna.

Frank

 

[slowmover]

Recently moved — and to get to the office across the property versus a seven-mile drive — I take the 4-whlr track in my 9,000-lb 2WD whacking live oak and pecan tree branches both directions of the half-mile idling along in First using clutch & brake for headway.

I usually have 3’ of vertical clearance. When I don’t is when I’m leaning against the drivers door due to the cant . . so it’s more, sorta.

.

 

[FKimble]

If your coax unscrews fron the back of the radio, then the damaged spot can be cut out and a male and female connector can be attached to the cut ends. Then these will be screwed together and wala, a whole working coax! No need to have to buy a new antenna.

Frank

 

[sumradioguy]

As a computer engineer, I can tell you that it's junk if a coax cable took a hit like that. Just replace it. You probably aren't seeing the capacitance issues at your levels you are measuring. Capacitance can really screw up signals at VERY SPECIFIC frequencies.

 

[niceguy71]

As a computer engineer, I can tell you that it's junk if a coax cable took a hit like that. Just replace it. You probably aren't seeing the capacitance issues at your levels you are measuring. Capacitance can really screw up signals at VERY SPECIFIC frequencies.

I don't know.... the coax feels perfectly fine....
the water heater and dolly slid forwards... I don't bother to tie it down as it can only go back and forth a couple feet... never had one move... that rubber mat makes things next to impossible to slide..... I generally only do 35MPH to the scrap metal yard a few miles away..... but as I said one in a million shot as the round arch of the dolly just happened to hit that 1/4 inch wide coax

it's just the strangest thing, every time I take my F150 out, I talk to locals in my area... since it's happened I have not been able to talk to one person??? but I have not heard any local traffic either... I hear tons of skip
so tonight I went to the Texas Road house ( once a week) I tried a radio check on 19 for half way there. maybe 10 minutes...... NOTHING... so I tried the guys on Channel 27... again quiet just some skip off in the distance.....so I put on 37 LSB.... it was nothing but people talking on top of people!!!
I was doing 75 MPH and got contacts in Washington State.... Texas..... Florida.....New Mexico and Jamica.... in less that 2 minutes.... so it seems to work??? ?but this is the longest I've ever not heard or talked to anyone on AM.... guess I'm just not finding people on AM like I normally do... if I don't hear someone next time I go out I'll do the video camera test.... and that will tell me if I got lucky or not.
I was thinking I could glue two small pressure treated boards/ blocks on either side of the coax..... but in 40 years of owning a pick-up, I've never had anything slide and hit the front of the bed... so I'm not changing a thing.