Mobile HF UHF/VHF Install Questions

Discussion in 'Survival Communications' started by 3M-TA3, May 27, 2018.


  1. 3M-TA3

    3M-TA3 Cold Wet Monkey

    Stupid question time... I bought a new (to me) truck last winter and It's time to install my mobile transceivers and antennas. Equipment is the following:

    HF path:
    • Kenwood TS-480 SAT
    • Transceiver and antenna support 80m and up.
    • Chameleon Hybrid antenna base w/ Breedlove folding QD attachment
    • Chameleon V2L mobile antenna (covers 80 through 10 meters, plus 6 meters, 2 meters, 1.25 meters and 70 cm)
    • Chameleon Mil Extension (used only when stationary)
    • Always mounted in a Breedlove Camper Top stake bracket (driver side)

    VHF UHF path:
    • Kenwood TM-710DG (antenna has built in folding feature)
    • Diamond SG7500NMO dual band antenna
    • A 2 position antenna switch (likely a MFJ-2702) selects between:
      • In Town mounted on a Breedlove Camper Top stake bracket w/ NMO adapter (passenger side)
      • In outback antenna moves to a mag mount on the roof. Considering the longer higher gain SG7900NMO dual band antenna for this base. when not in use the mount can be stuck inside the truck bed ala @BTPost
    And a crude visual overview - most likely location for radios will be under the rear seat.
    upload_2018-5-26_18-45-31.
    And an oversimplified schematic (EDIT: Added CB antenna to Antenna 2 of the TS-480SAT
    upload_2018-5-28_15-46-3.
    Stupid questions inbound:
    1. What coax to select? As you can see the runs are pretty short likely 10' to 15'. Is Belden RG8 a good choice for both the HF and UHF/VHF signal paths or is there a better alternative? I am crimping my own connectors and sealing the connectors with waterproof silicone tape.

    2. Bonding, James Bonding. I plan to bond the snot out of this truck and from front to back the following:
      1. Hood (bonnet to non Yanks) at the hinges on both sides
      2. All four doors
      3. Cab to frame - what points do you suggest?
      4. Bed to frame at all four corners
      5. Dual exhaust in two places on each side
    3. The stake pocket mounts extend 4.5" from the center of the pocket to provide clearance for canopies and racks. When not using either or hauling would it make sense to turn them inwards to get more metal mass under the antennas? Here is what the stake pocket mounts look like:
      [​IMG]

     
    Last edited: May 31, 2018
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  2. Tevin

    Tevin Monkey+++

    As for coax, that decision is more or less going to be made for you as the tight spaces and tight turns will make the thick "good" coax hard to work with. The good news is that your runs are short so the losses will not be too bad no matter what you use. Getting RG8 through the cracks and around the bends will be a challenge, but if you can find a way to make it work, go for it. I am a truck guy too and always had to resort to the thin cheap stuff.

    I use and recommend this coax loss calculator: Coax Loss Calculator

    Bonding: There are a lot of arguments over this. Some say bond the hell out of everything. Others say that the metal parts of a car are already well interconnected electrically, so more bonding is redundant. Smaller cars with a lot of plastic may need additional bonding, but a full size truck with a lot of metal surface area gives you a built in advantage.

    At the very least make sure the coax braid is electrically connected to the truck, preferably at both ends. Beyond that, I suggest before undertaking any additional bonding projects you test your systems and see what you've got. If the SWRs are good, and you're getting consistently respectable signal reports, and not getting (or causing) interference, then leave it alone. Don't make this harder than it needs to be. Preemptively grounding everything is a lot of work and you may not see much if any benefit from it. It's possible you could even introduce trouble that was not there before.
     
    Last edited: May 27, 2018
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  3. techsar

    techsar Monkey+++

    "Crimp" your own connectors?!?! solder those puppies.
     
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  4. BTPost

    BTPost Stumpy Old Fart,Deadman Walking, Snow Monkey Moderator

    Howdy, I just finished a similar install on my 2006 White Toyota 4X4 Pickup Truck w/Fiberglass Canopy. since there are only two of us usually ever in the truck 99% of the time, and this vehicle is a Road Trip vehicle, we usually leave the Access Seats Folded down, and both T/R Units are mounted under the Passenger Seat side Access-Door Rear Seat. I ran a Single Power Feed, direct from the Battery, made of of #8 Marine Wire. (about 10ft) I used a Good Quality Beldon RG-58U Coax for all the Antenna Runs... I drilled a 3/4" hole thru the Back Cab just under the Rear Window, and installed a Rubber Grommet for the Three Coax Coax Cables.

    The Vhf/Uhf Antenna is a DualBand Loaded Whip, mounted in the center of the Cab on a Big Heavy Duty MAG-Mount. My Brother (The Engineer) helped me install the Two HF Antennas, which I had planned to install just above the Canopy/Bed Seam, just in front of the Canopy side Windows, on each side, and Ground to the Bed with a Braided Ground Jumper of about 6". The Driver's side Antenna is the KW Super CB mounted on a Ball Mount that is mounted thru the Bed's Outside Vertical Wall , half way between the Read Seam of the Access Door, and Gas Cap Door, at the level of the Gas Cap Door. We decided this was a better install, due to RF Grounding Issues, ( I found the Truck Bed to Frame mounting had Issues with RF Grounding Impedance, so I added TWO Braded Ground straps, ONE on each side from the Bed Sheet Meta, to the Truck Frame) as well as He could reach up, from the underside of the Bed's Outside Metal to install the Ball Mount Hardware. I used SO259 connected Ball Mounts for Both Antennas. The Passenger side HF 80-10 Meter Tapped Base Loaded Antenna w/ Ball Mount was installed in the same spot as the Driver's Side HF Antenna, but on the Passenger side of the truck.... The Kw Super CB Antenna is connected to ANT1 on the TS-480, and Ant1 is connected to Ant2. Because my TS-480 SAT was down getting Referred at Kenwood Factory Service, (My eyes are getting to OLD to effectively work on Surface Mounted PC Boards) I mounted my backUp Base Radio from the Cabin, a TS-480Hx for this trip. The TS-480SAT is now back, and I will install it in the Truck, for our October Road Trip, coming up this fall. Both HF Antennas have a Nylon String that goes from the TIP of each Antenna and pulls each Antenna toward the Rear of the truck, and connects to the two Canopy Rear Door Latch Handles. This lowers the Vertical Height of the Antennas, to about 12 ft above Road Level, for Underpasses, and Garages... This doesn't seem to effect reception much, buy transmission is still being evaluated...

    Because you have a TM-D710GA, you may find that if you mount the Control Head where I installed mine, it may not pick up the GPS SAT Signals as well as if you mount it on the DashBoard, since the GPS Antenna is under the Plastic Bezel on the Top of the Control Head... In My Instal, the GPS Data comes from the AvMapVi which is mounted on the top of the DashBoard in the center, where the GPS Signal is more than adequate... I mounted both my Control Heads, on a Piece of moulded Plastic that fits over the Top of the Central Console Cup Holders, just behind the Standard Transmission Gear Shift. TM_D719a in front and TS-480 just behind. The Mic is the TM-D710a TouchTone Mic that is connected to an 8 Pole Double Throw switch, mounted on the forward vertical Face of the Center Console... that then connects to both Radio's Mic Connectors. The only thing i lose, is the UP/Down Frequency Buttons, that are on the TS-480... Those need the same wires as the TT-Pad on the TM-D710a Mic...I installed two External Speakers, one under each Front Seat. Driver's side is the for the TM-D710As VHF Radio, and the Passenger's side is the TM-D710As UHF Radio's speaker. The TS-480's external Speaker is mounted at the TOP of the rear vertical surface of the Center Console, that still allows access to the Center Console Folding Top Storage area. (where the travel Munchies live)...
     
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  5. Tempstar

    Tempstar Monkey+++

    Since I've done this, I'll offer up what I did differently:
    Run 2 mics. Run two external speakers. Didn't need additional grounding with either a Silverado or an F-150. I ran RG-58 (20' each) inside of 3/4" flexible conduit under the truck, and exited under the back seat instead of thru the cab wall. The V2L will whip around quite a bit at speed and I finally put heat shrink on the steel portion to stop it. This could have just been my particular mounting position. Make sure to use the HYBRID and not the mini. The mini will not stand up to the stress. Use putty on the connections because water will get in mobile that wouldn't in a standing still application. Don't expect HF performance like you get at home. Drill the hole and mount the V/UHF antenna on top center of the cab as the difference in antenna propagation makes it worth it. I've never had an NMO mount to leak.
     
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  6. DKR

    DKR Raconteur of the first stripe

    Do you have any problems drilling into the side ot he bed? A 3/4 in hole?

    If drilling is OK< consider a heavy duty ball mount for the HF antenna. You will get a 'better' ground...
     
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  7. 3M-TA3

    3M-TA3 Cold Wet Monkey

    Technically I'm doing both. I was just trying to indicate I was building my own cables more than anything else. Best practice from what I've read (and you know just how reliable Internet and vendor information is) to solder the center pin (also makes is waterproof) and crimp the braid since solder can cause work hardening. I invested in a high quality crimp kit that uses Andy-Crimp pro crimpers that will solidly crimp any connector I'm likely going to run across.
     
    Last edited: May 27, 2018
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  8. 3M-TA3

    3M-TA3 Cold Wet Monkey

    • The conduit idea is brilliant.
      • How did you seal the conduit to prevent water from coming in under the cab?.
      • How about the exit? Just fill it full of silicone caulking or did you use silicone tape?
      • EDIT - just saw you used putty - what product did you use?
    • I dig the heat shrink idea and thanks for that insight. Using the pocket mounts the antenna will be hanging about 3 or so inches outside the bed. I do plan on folding it down or even removing it when I'm not actively using the HF rig.
    • I did get the full size HYBRID.
    • I am thinking more about the permanent roof mount and using a cover when the antenna isn't installed. Several of the parking garages here only give me a few feet of clearance and I don't want to have to wonder if I'm up or down, which is why the cab mount is an "outback" only option. The stake mount locations I can check visually when I'm in the city.
     
  9. 3M-TA3

    3M-TA3 Cold Wet Monkey

    Any recommendations for an SWR meter? This Daiwa CN-801 1.8~200Mhz HP type cross needle SWR power meter is on Craigslist locally for $70
    [​IMG]
     
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  10. techsar

    techsar Monkey+++

    Not a bad meter...or price. I've got one similar..IIRC cn-501 v/uhf.
     
  11. Tempstar

    Tempstar Monkey+++

    I used the connectors made for the conduit. Sealtite is what it's called around here, Lowes has it. Keeps water out of the cab. The other end comes up under the bed with no connector, just HVAC sealing putty:

    https://www.amazon.com/dp/B07BK77DVF/?tag=survivalmonke-20

    An HVAC supply house has this as either Permagum or NRP Refrigeration Sealant in 2 lb. blocks. I use it on any connection outdoors. It will turn ugly looking in the weather but remains pliable and water tight forever. It's made for refrigeration use so it will take the cold easily.

    A 3/4" hole saw will make short work of the hole in the floor, just make sure no brake or fuel lines in the way, and no wiring.

    I have gone to crimp connectors as well. Picked up some that have a crimp on center conductor pin as well as the shield sleeve. They are nearly as waterproof as N connectors.
     
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  12. 3M-TA3

    3M-TA3 Cold Wet Monkey

    Playing around with mounting options. I'm going to place the TM-D710GA control head in the cubby above the console radio/nav unit (also Kenwood) on top of the dash. That gets the GPS in a higher position as @BTPost mentioned, and I don't like cubby/clutter trap areas anyway so it never got used. The TS-480 SAT will get mounted to the console drawer (but not crooked like in the photo) which is plenty strong and the drawer latch is still easily accessible. All the control heads will be easily accessible yet won't interfere if I have a third passenger up front in the middle seat. I may have to fiddle with the panel mount brackets a bit or even make my own bases to fit the QD panel holder. That QD holder is nice since I can quickly remove the control heads for security or maintenance.
    upload_2018-5-28_10-19-50.

    upload_2018-5-28_10-36-2.

    Now, where the heck would I mount a CB? I'd like to work in a Uniden BearTracker 885 because of it's additional emergency bands. Too bad CB's don't come with control heads like HAM equipment.
     
    Last edited: May 28, 2018
  13. Tempstar

    Tempstar Monkey+++

    You could use the TS-480 for CB.
     
  14. 3M-TA3

    3M-TA3 Cold Wet Monkey

    Ohhhhh.... explains why @BTPost was using the CB antenna above, and it looks like the MARS mods opens it up which I have already done. More money for other stuff - thanks!

    EDIT: My intent for CB is more RX rather than TX, which my understanding is only OK during an emergency with HAM equipment.
     
    Last edited: May 28, 2018
  15. ghrit

    ghrit Bad company Administrator Founding Member

    TS480 will Rx CB without mods. Tx will require internal mods to permit use in the CB frequencies. And yes, FCC rules will allow emergency transmissions by any means available, including using equipment that is not normally legally used on any particular band. I do NOT know if the MARS freqs ovelap CB or not.
     
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  16. 3M-TA3

    3M-TA3 Cold Wet Monkey

    Decided I'm going to cover the CB aspects with a compact off road type that has all functions in the handset and a small remote mount body/ Currently looking at a few like the Uniden CMX760 and the Cobra 75WXST; likely others as I become aware of them. These have small bodies that can be mounted under a seat or on the firewall. Looking to see if any support SSB.
     
  17. ghrit

    ghrit Bad company Administrator Founding Member

    When I left CB all those years ago, they had SSB, should be no problem. Had a Cobra in the pickup and a President as the base.
     
  18. BTPost

    BTPost Stumpy Old Fart,Deadman Walking, Snow Monkey Moderator

    What I did was dial back the Power on the Memory Channels that had CB Frequencies in them to about 5 watts.... Since CB has gone to the FCC Blanket country-wide License, and doesn't require an individual Station License, I figure that since the TS-480 is Bets the TECH Specs for a CB Radio, in all respects, I figure that is good enough for my uses... Sure is nice to listen to the Truckers chat about Road Conditions in front of us... That is info you just can't get anywhere else while traveling... You wouldn't believe how many Trucks we pass, that see the KW Super CB Antenna, on the Drivers side and comment about it when we pass them... I usually give them a chat, when that happens....
     
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  19. 3M-TA3

    3M-TA3 Cold Wet Monkey

    Did you have to do anything beyond the MARS mods to open them up for TX?
     
  20. BTPost

    BTPost Stumpy Old Fart,Deadman Walking, Snow Monkey Moderator

    Nope....
     
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