Skipjack 1/72

[greenman407]

I wonder how a "loaded" antenna would work underwater. The model airplane guys use them and I have one on my Airboat.
Maybe I shouldnt add complexities. If it works....dont fix it.

[roedj]

I wonder how a "loaded" antenna would work underwater. The model airplane guys use them and I have one on my Airboat.
Maybe I shouldn't add complexities. If it works....dont fix it.

The question of a "loaded" antenna is, well, a loaded question - sorry, sometimes I just can't help myself.

Seriously, if by loaded you mean to insert a coil (inductance) at the base of the antenna to lower its resonant frequency - then yes you could do it. But to what end? By cramming this straight antenna (again, this discussion assumes that the antenna is of a resonant design and not an "active" type) into the confines of a submarine hull you have already added inductance (some of the antenna looks like and acts like a coil) and capacitance (some of the antenna will have parallel wires somewhere) which alter the resonant frequency in different directions. Inductance in series lowers the resonant frequency - capacitance raises it. After cramming that wire in there a 'super computer' couldn't figure out the resonant frequency so why should we try to intentionally adjust it?

As I said, don't sweat it. Do the best you can and be thrilled the damn thing works at all.

Dan

[greenman407]

Yeah..........what you said.......yeah

[greenman407]

Ok, here we go with how Im hooking up my accessories to my reciever. If anyone sees something out of place, speak up. After Consultation with HWSNBN I have edited this post to reflect the recommended order.

CH. 1 Rudder servo
CH. 2 ADF- Rear Planes Servo
CH. 3 Sail Plane Servo
CH. 4 LIPO Guard-ADF Failsafe- Y connector-SAS Pump
...........................................Y connector-ballast vent servo
CH. 5 Blank
CH. 6 Speed Control
CH. 7 Blank
CH. 8 BEC


Ch. 6 I have assigned to the rotary control on the upper left on the Polk. I use it for throttle on all my subs for 1 screw and for two screws I use the rotary knob on the right for the other prop.
Weird thing is that on my Polk, ch. 3 and ch.4 are reversed in the radio. Perhaps because I asked Polk to send me a radio with a ratchet action left stick. Perhaps they plugged the wrong plug into the wrong slot. Possibly. Anyway, when I go into the menu to reverse servo direction. I have to change ch.3 if I need to change 4. Confusing aint it.

[He Who Shall Not Be Named]

Your transmitter assignments is non-traditional -- but you're likely a left-hander too, so I won't ***** at you on that matter.

However, you want both the LPB and ballast sub-system servo (vent) working off a Y-lead that plugs into the fail-safe portion of the ADF2.

Neutral and the LPB does not run and the vent is closed. Stick/switch in the 'blow' position and the LPB motor runs and the vent remains shut (servo moves, but linkage arm elasticity prevents servo stall). Stick/switch in the 'vent' position and the LPB motor does not run and the vent opens.

http://support.caswellplating.com/index.php?/Knowledgebase/Article/View/363/23/the-sas-system---how-it-works

third page.

David

[greenman407]

Dave, if your going to send the back up ballast system, then why cant I leave the LPB on the toggle switch and the Back up emergency ballast system can then go in the traditional location on the stick opposite the direction of the vent? Whadaya think? Just exploring all my options to increase my entertainment without giving you a headache.

[greenman407]

If not I guess I need to order a Y lead.

[He Who Shall Not Be Named]

When you set the fail-safe side of the ADF2, you set it with the transmitter 'blow' stick/switch at 120%. After setting up the fail-safe, you then return the transmitters end-point back to 100%. When actuated via fail-safe operation the ballast sub-system servo will travel 120% to the 'blow' position. However, as you operate the ballast sub-system via the transmitter, a normal 'blow' will be 100% travel -- and no engagement of the emergency gas will happen.

Aboard the SD, you dial-in the ballast sub-system linkage so that you get a normal blow, without blow-valve engagement, at the 100% 'blow' position, However the blow valve will be engaged when the linkage arm goes to the 120% 'blow' position.

So, you will get an emergency blow (gas) only when the sub-system goes to fail-safe or you command a blow from the transmitter and add full trim to that stick.

The entire SAS ballast sub-system is operated from one channel.

You people!

M

[alad61]

Thank you Dan, that was helpful! Very helpful.
David likes to say "it is not rocket science" and I am learning how in so many ways that is true, but antenna dynamics seems to go beyond rocket science it goes into the realm of magic and pixie dust to me.
Alec, I hope my question did not come across as questioning you or your abilitities. It is not. I respect your skills and knowledge immensely. It is me just trying to sort out the little knowledge I have.

No worries Tom and no offence taken. As I tell my staff if in doubt ask a question, I know I do... A lot :biggrin:

[greenman407]

OK, Can do.

[greenman407]

After reading, again, the info provided on the SAS, it seems clear now why the LPB and the gas emergency system should be operated from the same channel, a spring loaded joystick. Its all together on one control and you wont accidentally leave the LPB running and forget to turn it off. Youd be venting and Blowing at the same time. Not good.

[greenman407]

Using A Deans plug to be able to disconnect the Motor bulkhead from the rest of the Subdriver for ease of maintenance. Also one up front at the water proof switch. I gave up the Tamiya plugs years ago as being unreliable. After the connection is made to the Motor Bulkhead, the extra wire is pulled up into the front compartment and stored there with the Battery.

[greenman407]

Not to change the subject but I was thinking.(actually I already thunked it before). The Klikon magnetic pushrod joining devices. Great Idea. I have never used them because I was afraid that they might come loose. I plan to strengthen the magnetic attraction forces by "Double Teaming". Just epoxy or CA two additional ones on for double the force. "May The Force Be With You...........young Padawan."

[greenman407]

When hooking up all the Gizmos dont forget that, because we are using an additional BEC, we need to disable the BEC built into the Speed Control. Take the plug from the Speed Control that plugs into the receiver and remove the red wire, the one in the middle. Take a small sharp pointy thing and lift the tab(see picture). Then remove the wire and tape it back to the wire with something. Its said that having two BECs going at the same time can cause interference.

[He Who Shall Not Be Named]

Excellent close-up photography, Mark! New camera?

M