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Can a 2.4ghz antenna be extended tto the top of the periscope ?

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  • Can a 2.4ghz antenna be extended tto the top of the periscope ?

    I'm giving this one more shot. Got out of the hobby after building a 32nd Parallel Type XXIII. I'm working on a Revell Gato and I have one of Dave Welch's kits. Finding a 75mhz radio is becoming frustrating. Can I extend the antenna for a 2,4ghz receiver to the top of the periscope or does it have to be the length if came with?

  • #2
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    "... well, that takes care of Jorgenson's theory!"


    • #3
      Check with Bob frist, he may still have the VEX 75MHZ radios , receiver and don't forget the add on crystal sets.
      someone have to pay the bill, I am a free loader as is.
      or quick look at this system
      Come with life time supply off receiver. Is very good transmitter. I have the same one. Is a hitec.
      When is gone is gone.
      I will pm you later.
      Just look at it ok.


      • #4
        Got VEX radios and receivers in stock and ready to go, at least for now. Once they're gone, they're gone!



        • #5
          Ok posted. I really want it bad but have one too many.
          just the 72MHz spectra rf module (no......) is over $60 or more. Is synthesized you could use every any channel one is very hard to find , if you running in back water, I know nothing, I see nothing. The transmitter is about $40 to $50, it can do + AND - shift. It will work with ANY FM receiver 72 and "75 " MHz Futaba, hitec, JR, airtronics, tower hobby, multiplex, chinese make odd and end, BUT no PCM. PPM ONLY
          want to try 433 MHz, it will work with it too. (Evil laughter).
          funny thing someone from Ebay want $100 just for the antenna.
          75 thing, if you really have to run on it, got a real hitec 75MHz module and some dual conversion RX .
          sine I started you on this, if you pick up the system. sent me 4 of receiver I put a Expander antenna on each.

          Sorry Bob, got carried away.


          • #6
            Bob, how about crystals? That seems to be the real tough item to find.

            I've had some experience with Futaba 2.4 receivers that had small connectors for the antennas on the board. I don't know about making up a cable with one of those connectors, but I do know that some laptop's I've disassembled have had the same connectors for the wifi, with long lengths coax cable with those connectors already on them. Might be possible to pick up some used laptop cables and use them with a futaba receiver.
            "It does not take so many words to speak the truth" Chief Joseph


            • #7
              Longest one I could find is 600mm / almost 2 ft..may be go to the "green center" find a big ass laptop take out the wifi cables .
              so i end up with cheap stuff RX, plan to cut the end off, solder to the pcb. Also have some cable like what Dave has. You really have to set up the RX frist, find out how long as needed.
              most of the dual conversion RX is huge. Single conversion is a bit smaller, please give Bob a call. To match things up for you.


              • #8
                Guess that settles that. I was concerned that the receiver would be affected by other than stock length of the antenna, but running it up the periscope works for me. I'm thinking a subdriver is the way to go until I use my other kit later.


                • #9
                  Periscope depth is my wheelhouse........I LOVE 2.4Ghz for Subs! I tolerate 75Mhz lol

                  Probably the only one who does, I see it's benefits outweigh the need to dive below PD in my waters.

                  As far as running the antenna, I just followed what Dave Merriman suggested above, here is the COMPLETE post:
                  How To Adapt The 'New' 2.4gHz Gear To R/C Submarines

                  More in my post here:
                  Right you are Bob Martin…..

                  You need to pop open the receiver and see if you have an IPX connector or if the antenna is directly soldered as in Dave's example.

                  Hopefully you have the IPX connector then you can buy 4 feet of Coax cable with one on each end, cut that in half, giving you two, 2ft antennas to strip and modify the "above water end" like Dave's example (1.25" exposed center conductor, SEAL with moisture proof heat shrink!!)

                  How to replace snap on IPX antenna on FrSky and many other brands
                  How To Repair 2.4Ghz Receiver Antennas
                  Just replace one of the two on the RX.

                  Order here (4 ft [48"] of RG178 w/an IPX /u.fl at each end cut in half gives you one + spare!)
                  SuperBat Custom Cable Assemblies

                  So friggin' easy, soooo reliable! I love 2.4Ghz!!

                  Don't use a floating wire like some have suggested on other forums, I just use a very tall mast. Who gives a $#*!. No one will go over to the boat and measure it, and you're not running that puppy in a pool to dive deep.
                  Look closely at the middle scope in this video....
                  1-The first is the Attack Scope (a modified Afghan Sewing needle!)
                  2-The second is the NAVSAT MAST, the white portion at the very top encloses the exposed 1.25" 2.4 Ghz antenna. I thread it up from below through the hollow mast and it's held in place with a clip.
                  3-The third is my snorkel induction mast, which is used like a real sub to draw air in through a waterproof diaphragm pump as a LPB to surface, saving on gas for just and Emergency Blow backup.
                  Getting ready for Groton , USS SHARK SSN-591: MOD 3 Sea Trials 2019-08-11 (1:48 DeBoer Skipjack)

                  I hope to make a video soon on the details of 2.4Ghz Radio setup for the RC Submarine.

                  Something further to consider:

                  You understand what I meant by purchasing a 4 ft length and cutting in two to have two antennas, right?

                  You can adjust that length as required.

                  Lets say the total distance from tip of antenna, through the scope, into and through the superstructure to the receiver compartment is three feet.

                  Then you'd need 6 ft total length when you purchased. Just try not to exceed 4 ft on the final cut length itself, losses over length does occur, that's why I wouldn't go with a "floating" antenna.

                  Another thing I do, for every receiver I have (5 boats all use the same RX) I buy a 10cm (4") length of RG178 with the IPX on one end, and an SMB straight Plug on the other.

                  Then I order the 2x Antenna length, but with SMB Jacks on each end. which of course will give you two antenna's, but with the SMB straight Jack's on the end

                  This way if the antenna becomes damaged and can't simply be repaired (IE, the tip broke, and you just need to shorten it) you can replace it without opening the Receiver. Plus it makes it easier to run through a bulkhead seal and relocate the RX as necessary without it hanging off a long as cable..

                  This is a photo of what I actually ordered at SuperBat.

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                  Here on SHARK you can see what I mean:

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                  Note, because the top of his box is at the surface waterline, I make use of the 2nd antenna I didn't change by running it through a Pressurization/Equalizing Tube, which is capped by that aluminum fuel plug. It is actually above the water in the superstructure when she's surfaced, and I have both antennas available for the best possible reception.
                  It's there, why not use it? The hose of course is used to check for leaks.
                  v/r "Sub" Ed

                  Silent Service "Cold War" Veteran (The good years!)
                  NEVER underestimate the power of a Sailor who served aboard a submarine.


                  • #10
                    I can almost hear" Igot You babe" by Sonny and Cher... Thanks for reposting that ...