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Mobile Roof Puck Mount

Discussion in 'CB Antennas' started by Slowmover, Dec 13, 2019.

  1. Slowmover

    Slowmover Sr. Member

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    A5A184ED-6C85-42EE-B78C-30547EDB0ABB.jpeg

    For those not familiar, a pickup tends to haves pair of “squared” plastic grille vents spaced equidistant on the rear of the cab wall near the beltline in height. (Shown with truck bed removed).

    Mounted behind the rear seat-back and the whole of that wall covered with sound-absorbing material, there will be openings nearby to accommodate air movement. A one-way air flap prevents exterior air entry (rain).

    When you go to shut the doors with the windows all rolled up, the vents equalize the pressure.

    Their HVAC role is low, but real. If interior air pressure were to build to a number above that of the exterior, they relieve the discrepancy.

    But I wouldn’t go so far as to think of them as vents that do very much in that regard. (Removing stale air).

    WEATHERTECH interior-window-channel “vent visors” mounted at the top of the doors exterior are quite effective vents . . literally pulling more air thru the HVAC vents than can be heated or cooled at times.
    292344B0-B6B7-4102-AC0D-316962B84E89.jpeg

    I recommend them highly. Also a handy pathway to run coax thru a back window and route to back of cab. Then use black, “gaffers tape”, both sides of window to seal gap. No rain, no extra noise. No one can see window cracked.



    As a pathway for coax, the cab vents are out of sight and out of mind. I’d imagine most would route down passenger side door threshold after installation. Those mounting HAM equipment under the rear seat (detachable head) have a truly short coax run to an antenna for mag mount.

    It’s probably one-dozen bolts to get rear seat from 3rd Gen Quadcab free to lift seat back off of hooks.

    I’ll count tomorrow. Whenever. Son came by today and nothing much got done except exercising jawbones.

    .
     
    #46 Slowmover, Dec 27, 2019
    Last edited: Dec 27, 2019
    Handy Andy and Woody-202 like this.

  2. Slowmover

    Slowmover Sr. Member

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    A783BDB8-BFF6-4BA0-BEAC-FDEC891ABF73.jpeg

    - Tapered the leading edges.
    - Adjusted the magnet cover drain holes for lowest aero resistance.
    - Found the TopGunTec multi-part HD SS antenna stud.
    Bobs CB
    PID-2274
    $19.95

    Some MoJo brand metal polish to lower skin friction to a null value.
    (by Roadworks; thru the IOWA 80 chain)

    Get out your pocket comb and adjust your part with that shine.
    The SuperStar Launchpad is ready.
    Latest alien tech antenna aboard.

    (No, it didn’t look like this 20-years ago when I bought it.
    An old hairy hippy truck driver clued me in on this polish.
    That’s five minutes work.
    Now, I can say I got something done today after all).

    18’ Mini-8 + chrome, baby.
    QRM/QRN problems cease to exist.

    I’ll have to adjust the radio.
    Signal may now be too fast for others to catch.

    .
     
    #47 Slowmover, Dec 27, 2019
    Last edited: Dec 27, 2019
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  3. Mudfoot

    Mudfoot Elmer

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    Purdy....

    I bet that plate would shine up nice. I have a mount like that. I like it, but my Jeep has the roof panel ridges that keep it from making full contact. It'd be expensive, but I'd like to replace my existing magnets with Neodymium. That would make an extreme magnetic bond.
     
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  4. Slowmover

    Slowmover Sr. Member

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    This mag-mount is already hard enough to remove from the roof.
    That’s with the leverage afforded by using a ladder.
    I can’t imagine an even stronger magnet set.
    One would need some sort of non-marring plastic-covered pry bar.

    I guess a flat nail-puller with multiple coats of liquid plastic.
    And a handle extension.

    Or just mount some electro-magnets on the interior side.
    Hit the juice and watch that mother launch itself.
     
    #49 Slowmover, Dec 27, 2019
    Last edited: Dec 27, 2019
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  5. Woody-202

    Woody-202 Sr. Member

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    Wow Slow, that tidbit of information scratches an itch I've had for awhile(y) and now I'm off to WeatherTech...
     
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  6. Slowmover

    Slowmover Sr. Member

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    The brand quality is excellent — and being able to moderate airflow past what the HVAC fan can accomplish — is by itself worth the price of admission.

    .
     
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  7. 2NC995

    2NC995 DAN

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    My truck got visors and front/ rear weather-tech mats the week I bought it. Haven’t seen the floor since..lol.
     
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  8. Slowmover

    Slowmover Sr. Member

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    I’ve been at home longer than I thought I’d be. Nothing happens till after the year starts. Probably have up to a week before I leave again. Determined, thus, to organize the Silver Streak better than its been the past three years.

    Have decided to dedicate a set of cabinets upper & lower to radios and gear. But that has entailed one helluva lot of organization & condensing gear, tools etc down to minimal dimensions. Wow.

    Have found quite a few things . . is that funny or pathetic?

    Every time I think, “okay, I’m done with this, I can go outside and start some bonding or whatever” — and I look for tools, etc — I realize, nope, still more to do.

    Funny or pathetic guys? ‘Cause I just found a roll of toolbox drawer liner and of course that’s EXACTLY what I need to line those cabinet shelves since, as it’s a travel trailer, I might move it.

    Hmmm, . . .

    I’m just glad I haven’t started buying the cabinet lights I’ve been eying.

    .
     
  9. Slowmover

    Slowmover Sr. Member

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    Thinking right now I’ll try that “mount” you've used. The 99v2 Galaxy on a raised height mount I bought from Clays Radio Shop. Must be close to a foot tall. That leaves room for an RM ITALY 7405 plus another WEST MOUNTAIN RADIO CLEARSPEAKER and I can leave it all in one place. A UNIDEN BC-20 in the meantime. Just need a third leg to brace it.

    I haven’t closed out the thread on the Peterbilt, it went well enough till putting the TAC COMM carriers together (too many pieces to spread around without a proper tabletop) so I think I’ll carry along the Unidens 989 & 885 from hereon whilst truckin’.

    So,
    am actually closer to getting tri-mag up after I yank rear seat. No more decisions what gear to run “permanently “ in the pickup. Have measured power runs (and what’s already installed, but needs new terminations), and it can handle 20A (100w+) for the circuit length.

    Edit: And I guess I’ll have to take some underhood pics for Redbeard.
    Do justice to a double-battery Cummins-engined Ram. Get that 2970 of his installed.

    .
     
    #54 Slowmover, Jan 1, 2020
    Last edited: Jan 1, 2020
    22racer likes this.
  10. Slowmover

    Slowmover Sr. Member

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    Past few days have spent a few hours each on laying out coax plus power runs.

    Yesterday and today has been RF bonds after cleaning nearly all the factory DC grounds (have done this now three times over past dozen years; glad I don’t live in snow country).

    Most of today was on my back under truck and figuring (based on current supplies) where to use my limited number of lugs.

    Got a question: the BATT grounds (dual battery system) are both to the engine block one each per side. K0BG & W8JI both stress connecting radio NEG to chassis adjacent to the vehicles BATT ground. Not on it. How would you proceed? (No, I’m not going to connect directly to BATT NEG).

    I have some fairly heavy cables (4-AWG; can raid the 2-AWG bag) I can connect to the batteries and run to frame. Drill x2. Drill a third hole for radio. Just doesn’t seem right. Or from engine grounds. (Past that I’m a dry hole).

    The Dodge system is a primary and a secondary battery. One to starter. And an 8’ POS cable across radiator to secondary (which exists primarily to provide the juice for the air intake grid heaters; no glow plugs).

    My radio POS run will be to the primary battery (10-AWG at present; 6-AWG would be tops in future; am guesstimating 12’ total with a near NEG connection)

    Thx

    .
     
    #55 Slowmover, Jan 5, 2020
    Last edited: Jan 5, 2020
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  11. Handy Andy

    Handy Andy Do Your Research First, Then Decide...

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    My own experience of being a Company truck driver (yeah, the ones that get told to go, whether they have HOS issues or not...)

    If there is a BRACKET that bolts to this relay that kicks in the 2nd battery, the system usually runs like a battery isolator - allow charging of both. That bracket should be the best Ground point or at the best equidistant point of least resistance TO ground as well as current load SHARING. That is why they recommended the SEPARATE close to frame and BATT ground - to reduce the likelihood of a load induced sharing incident.

    I've seen battery cables "spark" under load so I know that if you don't have things equal - one battery can blow it's own plates trying to start the truck because the other battery isn't at the same voltage potential as the other. The highest voltage output wins the race, but it can kill itself dumping into the demand in the process.
     
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  12. Slowmover

    Slowmover Sr. Member

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    Thanks, HA.

    The difference in potential had (has) my attention.

    Here, (repeat for myself) both BATT are common via a 8’ POS cable (one GRP 65 battery each side of engine bay) and each grounds respectively via bolt on its side of the engine block. Close to exactly-equal lengths NEG.

    I installed (2) 4-AWG cable left over from another job to connect frame rails to “their” side of the engine at those existing DC ground points.

    Then doubled up on the ALT feed cable to BATT (an upgrade 2-AWG from a few years ago, now also a 1-AWG).

    I may run another 4-AWG cable from Starboard frame rail to ALT case bracket. That’s where thinking came to a stop. (ALT is connected to block via OEM mounting bracket; two ground paths?).

    Radio NEG will be to a fastener on Starboard frame rail. That’s the theoretical closest I could figure.

    While I’m not burdened with the post-2010 Hall Effect Sensor which calls for this approach, there are yet other power additions to come (non-radio), and I’d rather have established a common ground point. (The weighs-a-ton starter is on the Port side).

    To sum up where the project stands:

    A). I have pairs braided jumpers at hood hinges installed, and from cab to bed. This evening finished fabricating (8) more jumpers to do the corners of both cab & bed.

    B). I’m guessing up to (12) more past that for the body and it’s attachments, plus about (4-6) for the 4.0” I.D. X 20’ exhaust. Looks like maybe (30-34) total will get me overall coverage, then it will be time to test. (Crawling under truck not so bad, it’s in standing back up; my survey isn’t yet thorough).

    C). Temp coax & power to go in tomorrow (just so I can hook up a radio to find l what I can hear across the mag-mount PRESIDENT TEXAS while parked here at home).

    D). Have yet to order BREEDLOVE mount. Or decide how to brace sheetmetal from underside (no survey done). Hoping they have insight to go with what I’ve read elsewhere.

    E). Will be getting back out of town shortly so project on hold till more time off avails itself (and weather is reasonable). Am surprised I had a weather window into the New Year. Other projects had precedence.

    I’m planning on being home every two weeks this year versus staying out 4-6/weeks at a time the last couple of years. A few hours more often ought to keep it going smoothly.

    Final Note: Condensing down my radio-related gear, tools and supplies to the least number of toolboxes, bags and transport cases involved far more time than I’d have imagined. Ha! Storage space is at a premium. Dividing it between home & big truck had gotten out of hand. (The upside being, “huh, forgetten I’d bought this”, about a half-dozen times).

    .
     
    #57 Slowmover, Jan 9, 2020
    Last edited: Jan 9, 2020
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  13. Handy Andy

    Handy Andy Do Your Research First, Then Decide...

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    Oh, ok.

    We have a Horse of a Different Color here....
    HorseColor.jpg

    Ok, you answered my question within the first 2 paragraphs...

    Then...and it's good to see this, use the ENGINE Block for your ground return. Alternator / Charging system aside, you'll need a reference so start there. Your Regulator is on the Alternator - so why not keep the electrons busy...back at the Block...

    However, there is also a reference here to SINGLE grounding Point designs - kinda like the Podal - Anti-Podal approach if this may work better.

    First Podal refers to location of there you're at - where your feet or foot - is.

    Antipodal - refers to the opposite side (in light of planets and spheres, Earth)

    But since you're dealing with a radiating body, hence the use of the term...

    Use the ANTENNA ground (the Shields braid) as the point of return for the NEGATIVE Ground lead - therefore any ground current losses or issues would be lost on the sheer volume of metal as radiating body the triuk becomes. Ground opposite the Power feed.

    Coaxial Braid and simple power feeds can work together. Just not with big amps or high-power (read Amerage-hungry) radios that require AWG that exceeds the rating of power the Braid can safely supply.

    In my younger days, I got slammed for offering some advice on how to keep whine out of the HR2510 - the thread unwound beautifully into a great discussion about single point grounds. Single POSITIVE power wire to the harness close to a battery feed, and let the Antennas' own Ground Contact (being Braid to Mount point) be your NEGATIVE return as well as for Counterpoise - to lessen the eddy current ground loop effects.

    Since you're using a Mag-Mount, (correct?) It's best to stick with the Engine Block or EQUIDISTANT bonding point (Antipodal) of the Grounding Lead for the two batteries. You can bond ground to Frame - somewhere on the firewall - close to the center hump, by the Air Conditioning Heater Defroster Climate Control system - like a mounting bolt - heck they may even use it as the ground point for much of the Dashboard, including the on-board AM/FM entertainment system.

    To tear apart a dash is not for the feint of heart, nor one to be done alone.

    I know you don't have time - but try the engine block and then onto a more permanent bonding system when you get back - at least you'd try out the newer stuff you got (in combinations thereof) and work out solutions and different trials as you go thru your work days...

    We'll be here on your return trip.
     
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  14. Slowmover

    Slowmover Sr. Member

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    Thanks, HA. Your ability to organize thinking cogently does you great credit.

    1). A mag-mount first. (A puck-mount roof center second).

    2). One or another AM/SSB radio for now (might be capable of “more”, but I’m not. Yet).

    3). Initial power will be an approx 15’ 10-AWG circuit. I may “up” that at some future point. (30A peak draw).

    4). Truck will also get front & rear Anderson Powerpole jump-start capable cabling. (Charging trailer from either position is part of that).

    5). In addition, a power point near tailgate interior so as to run transceivers, whatever.

    6). First step towards 4 & 5 is an ambulance-spec alternator and 3/0 battery-cabling.

    I don’t anticipate using this Cummins as a generator for the trailer, but I’m not leaving it on the table either. Thus 4,5 & 6 are goals for the future. Not part of this project.

    For now, a roof-located puck mount for a tall antenna, (and an NMO-Mount to follow). (A screwdriver antenna I would mount off the bed; assuming I ever got that far).

    You can see why a central ground appears attractive. With the engine having a ground for each battery, I reached a stopping point for now. Initial radio swaps won’t be anything high-powered (30-50W).

    Not trying to talk past your thoughts. A restatement of mine.

    The distance from that hypothetical dash base ground point to an engine/batt ground is about (4) feet. That’s shorter than the distance from dash base to transceiver (seat mount for now; cabling run stays at perimeters to passenger B-pillar up to seat base).

    I actually have interior-to-engine bay access at passenger A-pillar near windshield. Comes out about 1.5’ from BATT NEG. Distance to Engine Ground is about the same as what’s on the inside. (It would be a longer run to go from dash center above Starboard frame rail).

    Think (roughly) straight line from B-pillar up to windshield base on A-pillar to Batt, then 90-degree turn plus height change down to Engine Ground (following current BATT NEG ground ground).

    At this point in time, the BATT POS lead would be 3’ shorter than the NEG home run to Engine Ground.

    I’m in favor of the simplicity in having Engine be central ground point.

    Thanks again for your insights/suggestions.

    .
     
    #59 Slowmover, Jan 10, 2020
    Last edited: Jan 10, 2020
  15. Slowmover

    Slowmover Sr. Member

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    As things stand, continuing RF bonding will be where the project picks up again. I’ll be ordering more 1” wide tinned copper strap in a long roll, plus lugs & heat shrink.

    For S & G I’m going to look into using Redbeards reply of trying expanded metal mesh to line Fiberglas topper. I see that Lowes carries it in aluminum sheets. As I can use an amount for an unrelated job, I’ll be curious to see how easily I could bend it for close fit.

    Were that undertaken, it would be the finish to RF bonds (besides a better one to/from the trailer in conjunction with a better DC ground).

    K0BGs idea of 3/16’s aircraft cable as static drains for both vehicles, also

    .
     
    #60 Slowmover, Jan 10, 2020
    Last edited: Jan 10, 2020

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