75 MHZ radios AVAILABLE!!!!!!!!!!!!!!!!!!!!!!

[greenman407]

I was feeling quite comfortable with my Polk Tracker. That is to say......until it died. I tried to get it repaired but that was not successful. Ive been watching EBAY for them for the past year and theyve all but disappeared. In fact......any and all usable 75 mhz radios have VANISHED from the face of the Earth!!! With the help of Bob Martin, I not only acquired another Polk, but thanks to him I have discovered a STASH of almost 2000 six channel transmitter and receiver sets. If you are interested......and you should be I would think, check out this link. Bob Martin bought two of them and hes testing them out now. Hes supposed to give me an accessment of them soon.http://www.vexrobotics.com/75mhz.html

[greenman407]

If you will notice on the back, there are two buttons for ch. 5 and two for ch. six. Im hopeing that you hold the button and it will move your servo up thru its range and stop where you need it to. The other one will move it back down. Perfect for a throttle or a bow plane. I dont know about the receiver setup however. Im hopeing that I can use the transmitter only and use it to drive my Sombras. Bob Martin is checking that out. We will know soon. I for one will purchase one If all goes well with the tests.

[RCSubGuy]

VEX radios work perfectly with Sombra receivers. The pairing was virtually instantaneous and they seem to work well. Each radio does come with a receiver, and when paired with the splitter module, can then run standard servos with no problem. The four rear buttons operate channels 5 and 6. Pressing the top or bottom button of the channel moves the servo to the corresponding end throw and releasing the button returns the servo to center.

The radio does have many programming features that may allow you to change the behavior, but I haven't researched that aspect yet.

Good news, for sure!

[george]

Hi
Excuse me for jumping in here. I have two of the same radios,NOS for sale at a MUCH better price than that company.
George

[vital.spark]

I noticed that they have a regional office here in Hong Kong so I gave them a call. They actually have some stock here so if I purchase no need to pay shipping!

[He Who Shall Not Be Named]

What bothers me is that channels 5 and 6 are latched to full throws only. Damn! Other than that, looks like a deal. And how big is the receiver and the associated device that interfaces servo-ESC-MPC-LipoGuard-ADF- leads?

M

[trout]

So far I read it interfaces with sombra labs with no problems. My only concern is only one channel I see offered, 89. I am sure there has got to be other modules, but where? Or can the module be hacked to have changeable crystals?

[RCSubGuy]

It looks like they use standard transmitter crystals, but I don't have any spares (or extra time) here to check with.

Yeah, momentary throws on 5 and 6 area bummer, but they're still useful for torpedo firing, APC emergency override, sound module activation or any number of other applications.

The receiver is just a bit bigger than a standard hobby-grade one, but the splitter is a bit bigger than that. Basically you'd need to allocate double the room in the cylinder. Just fine for big boats with lots of room, but crappy for small boats with tiny cylinders.

Like I said, they play nice with the SL-8, so really that's not a huge issue if they'll talk with standard receivers on the same channel.

[greenman407]

So for all intents and purposes we have here a four channel radio. Most subs only need four channels. My Skipjack and Albacore and Seaview will work fine on it. The Oscar and the type 23 have bow planes so I need five channels for them. I wonder.

[vital.spark]

5 or 6 can be used for ballast tank and LP blower?

[greenman407]

Not ballast tank, that needs to be proportional

[RCSubGuy]

Why does the ballast tank need to be proportional? Vent is either open or closed. Blow valve is the same. I suppose you could do some very fine tuning with proportional control once you got very familiar with where the throws were, but at the rates the SubDrivers expel or release gas, full throw is just fine.

[greenman407]

Thats a good point Bob. I prefer a more scale-like Blow with a Gas system, which most of my submarines are. Ive been able to "Hover" , by carefull proportional control of the ballast channel. I guess it depends on the user. Case in point. The following short video of my Albacore which uses the D&E 3" WTC which uses a Propel operated gas system.https://vimeo.com/10523913

[vital.spark]

I agree with SubHuman on this point Mike. I have a visitor in town now but I'll see if I can make time next week to get over to VEX nest week.

[trout]

Mark,
You negatively balance your subs?
I thought you positively balanced your sub and ran as dynamic (SubHuman, I can guess what you are thinking or going to say "You think I am confused", probably)