Go Back  RCU Forums > RC Airplanes > Questions and Answers
Reload this Page >

What to do w/ 72mhz?

Notices
Questions and Answers If you have general RC questions or answers discuss it here.

What to do w/ 72mhz?

Old 02-22-2014, 04:36 AM
  #26  
SrTelemaster150
Senior Member
 
SrTelemaster150's Avatar
 
Join Date: Feb 2012
Location: Brasher Falls, NY
Posts: 3,904
Likes: 0
Received 2 Likes on 2 Posts
Default

Originally Posted by Neverlost1
I know what you mean. I have five or six 72MHZ radios I haven't used in years. I just can't seem to part with them because of all the money invested over the years. I would still be using them, but, I transitioned to 2.4 because most of my airplanes now have gas engines. The ignitions throw out a lot of RF "noise" that 2.4GHZ seems to be more immune to.

I almost lost my first gasser using a 72MHZ radio. I had two problems on my maiden flight. The throttle servo failed at the full position so I couldn't land until I ran out of gas. The bigger problem was every time the airplane was at one end of the field, it would go "wild" from radio glitching, but I managed to save it each time, just before it hit the ground. I did a radio ground range test prior to flying, but not with the engine running (big mistake). Range testing after that flight, I could only get about 10 paces from the airplane before the servos went wild when the engine was at full throttle. I then changed over to 2.4GHZ and have never had any more "glitching" problems (but I still range test at full throttle, just in case).
I flew CDI for years W/72 Mhz & never had any problems. A grounded shield plug lead & a few other precautions eliminated RF. That's not to say that 2.4 isn't less prone to RF.
Old 02-22-2014, 04:45 AM
  #27  
TomCrump
 
TomCrump's Avatar
 
Join Date: Apr 2003
Location: Traverse City, MI
Posts: 7,614
Likes: 0
Received 5 Likes on 5 Posts
Default

Originally Posted by Neverlost1
I know what you mean. I have five or six 72MHZ radios I haven't used in years. I just can't seem to part with them because of all the money invested over the years. I would still be using them, but, I transitioned to 2.4 because most of my airplanes now have gas engines. The ignitions throw out a lot of RF "noise" that 2.4GHZ seems to be more immune to.

I almost lost my first gasser using a 72MHZ radio. I had two problems on my maiden flight. The throttle servo failed at the full position so I couldn't land until I ran out of gas. The bigger problem was every time the airplane was at one end of the field, it would go "wild" from radio glitching, but I managed to save it each time, just before it hit the ground. I did a radio ground range test prior to flying, but not with the engine running (big mistake). Range testing after that flight, I could only get about 10 paces from the airplane before the servos went wild when the engine was at full throttle. I then changed over to 2.4GHZ and have never had any more "glitching" problems (but I still range test at full throttle, just in case).
Your problems could be due to your setup. I flew 72MHZ on gassers for years.
Old 02-22-2014, 05:30 AM
  #28  
Neverlost1
My Feedback: (1)
 
Neverlost1's Avatar
 
Join Date: Sep 2008
Location: Ohio
Posts: 38
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by TomCrump
Your problems could be due to your setup. I flew 72MHZ on gassers for years.
Setup definitely played a roll and It was a combination of issues. The "electronic" Melody ignition was notorious for throwing out a lot of RFI (I had read one post where the comment was "Melody ignitions could shoot down a full size aircraft"). I replaced it with a RCExel ignition. And yes, by re-arranging components, I could get a successful range check with the engine running using my 72MHZ radio. I continued to fly a few times with the 72MHZ radio and still had some unexplained glitches. By now, my confidence was shaken, so I switched over to 2.4GHZ, and have not had any issues since.
Old 02-22-2014, 07:35 AM
  #29  
SrTelemaster150
Senior Member
 
SrTelemaster150's Avatar
 
Join Date: Feb 2012
Location: Brasher Falls, NY
Posts: 3,904
Likes: 0
Received 2 Likes on 2 Posts
Default

All of my Saito engines are converted to CDI W/glow fuel.

I flew that combination way back in the late '90s.

Some of the precautions I took in addition to the grounded shield plug lead that is standard on CH Electronic CDI were:

Keeping the Rx as far from the actual ignition components as pracical
Always using a non metalic pushrod for throttle such as Sullivan "Goldenrod".
Never installing the Rx in close proximity to any metal pushrods.
On the old metal cased modules, using an auxiliary ground from the engine block to the module case.

I never had a radio failure. (as long as I didn't range check in flight)
Old 02-22-2014, 09:11 AM
  #30  
RCFlyerDan
My Feedback: (54)
 
RCFlyerDan's Avatar
 
Join Date: Apr 2002
Location: SWFL
Posts: 2,000
Received 67 Likes on 50 Posts
Default

Retire it and throw it out, as you did with beta and VHS video recorders. Time and technology is moving on.
Old 02-22-2014, 05:14 PM
  #31  
mike31
My Feedback: (67)
 
Join Date: Aug 2002
Location: York, ME
Posts: 724
Likes: 0
Received 0 Likes on 0 Posts
Default

Use them!
Old 02-22-2014, 05:29 PM
  #32  
flycatch
Senior Member
My Feedback: (26)
 
Join Date: Jul 2002
Location: Barstow, CA
Posts: 2,027
Likes: 0
Received 6 Likes on 5 Posts
Default

Originally Posted by RCFlyerDan
Retire it and throw it out, as you did with beta and VHS video recorders. Time and technology is moving on.
What an ignorant comment to make.
Old 02-22-2014, 05:36 PM
  #33  
[email protected]
My Feedback: (1)
 
Join Date: Aug 2002
Location: hemet , CA
Posts: 1,164
Likes: 0
Received 0 Likes on 0 Posts
Default

keep the radios on 72 the most flyers at my fiels at any time are 8 all on 2.4 me iam on 72 they forget what plane thechannel is on and have a lot trouble not me
Old 02-22-2014, 05:46 PM
  #34  
flycatch
Senior Member
My Feedback: (26)
 
Join Date: Jul 2002
Location: Barstow, CA
Posts: 2,027
Likes: 0
Received 6 Likes on 5 Posts
Default

Gassers on 72mhz PCM work fine until the CDI systems fails. I have been there and done that. Replaced the CDI and problem solved but I stopped using gas engines. Word to the wise is never use a FM receiver for anything other than gliders. I test flew a H9 PA18 today on 72mhz with a PCM receiver and flew it out to a measured distance of 3000' ft with no problems. For all those who are advocates of 2.4 kHz talk to those who have lost their airframes while flying this technology. The new technology has not only helped the manufactures save money but has also taken the responsibility away from the modeler.
Old 02-22-2014, 07:07 PM
  #35  
skylark-flier
 
skylark-flier's Avatar
 
Join Date: Sep 2002
Location: VA, Luray
Posts: 2,226
Received 15 Likes on 13 Posts
Default

Pm sent
Old 02-22-2014, 07:20 PM
  #36  
JPMacG
My Feedback: (2)
 
Join Date: Jan 2002
Location: Ivyland, PA
Posts: 2,299
Received 1 Like on 1 Post
Default

72 MHz is actually a better frequency than 2.4 GHz for communications using omni-directional antennas. However, spread spectrum is better than FM or PCM. The best system would be spread spectrum on 72 MHz, but that will never happen because of the bandwidth required and other frequency allocations on 72.

Anyway, nothing wrong with 72 MHz FM or PCM as long as no one else is on your frequency. In fact it even has some advantages over 2.4.

Higher end 72 MHz computer radios still sell used for good prices.
Old 02-22-2014, 09:31 PM
  #37  
jester_s1
Moderator
 
Join Date: Dec 2006
Location: Fort Worth, TX
Posts: 7,266
Received 35 Likes on 30 Posts
Default

2.4ghz eliminated the most commonly encountered problems in RC- radio interference caused by stray signals, transmitter conflicts, gas ignitions, and vibrating metal on metal connections. True, it doesn't penetrate as well as 72mhz and never will because of simple physics. But it penetrates well enough for our purposes.

To my mind the old radios aren't worthless because they are 72mhz. They are worthless because of features. JPMacG made a good point that high end 72mhz radios are still somewhat valuable, but even they are hard to compare favorably to the 10-12 channel radios being currently produced. And when you add to that the years that are on these old radios that do take their toll on pots and solder joints, it's hard to make a case to keep using them.
Old 02-22-2014, 10:59 PM
  #38  
dlinares126
Junior Member
 
Join Date: Nov 2013
Posts: 3
Likes: 0
Received 0 Likes on 0 Posts
Default

I stopped flying in 2001 and just got back in 2013. I feel like I traveled back to the future, lol
Got a spektrum DX7s and it's bullet proof and not to mention the telemetry is really awesome, rx battery voltage, ignition voltage, engine temp, RPM, and flight log. Now I'm going to get a G force sensor just for s.... and giggles.

Last edited by dlinares126; 02-22-2014 at 11:02 PM.
Old 02-23-2014, 03:07 AM
  #39  
my05monte
 
my05monte's Avatar
 
Join Date: Feb 2007
Location: Louisville, KY
Posts: 133
Received 0 Likes on 0 Posts
Default

I learned on 72mhz and still use them today. I bought a 2.4 2 years ago, but its never left my shop. Guess I'm not comfortable with it yet. To me, its a matter of how much I trust my radio to do what I want.
Old 02-23-2014, 05:36 AM
  #40  
cigartoyz
 
cigartoyz's Avatar
 
Join Date: Oct 2013
Location: Coral Springs Fl
Posts: 58
Likes: 0
Received 0 Likes on 0 Posts
Default

If you fly FPV on 2.3ghz or 2.4ghz for your video tx/rx the 72mhz is perfect. Other than that its kind of old tech.
Old 02-23-2014, 08:23 AM
  #41  
proptop
My Feedback: (8)
 
proptop's Avatar
 
Join Date: Oct 2002
Location: Rome, NY
Posts: 7,036
Likes: 0
Received 2 Likes on 2 Posts
Default

I have no intention of getting rid of my 72 mhz stuff...some of the transmitters just fit in my hands so nicely, that they feel comfortable, and well balanced, unlike some of the stubby antenna's 2.4 tx.'s
I have a lot of it...(72mhz stuff)...and several newer radios on 2.4 as well...
Used to be when I'd go to the field, I would have to share the freq. board pin with someone else...now I can go out, and since most guys are using 2.4 I typically can have the freq. pin all day, if I want it...

One thing you need to remember though, if you get used to using radios on 2.4 and then switch to a plane w/ a 72mhz radio, is that you gotta remember to pull out the antenna!
A friend has an old 10X that has about 6 or 8" of antenna that doesn't collapse into the case...and he flew an entire flight w/o extending the antenna...kind of embarrasing, but luckily there were no problems. (good ad for an old JR radio, I guess)
Old 02-23-2014, 08:32 AM
  #42  
Sabreryder
Junior Member
My Feedback: (6)
 
Join Date: Oct 2002
Location: Plainview, NY
Posts: 5
Likes: 0
Received 0 Likes on 0 Posts
Default

72 works fine and there are very few people on 72 so you don't really have to worry about frequency conflicts. But do check and make sure that there is nobody on your frequency. One more caveat, if you fly both 2.4 and 72 remember to pull out your antenna on 72. Did it twice and crashed 2 planes. I then converted my Futaba 9c to Hitec 2.4 and it works great!
Old 02-23-2014, 11:42 AM
  #43  
hairy46
My Feedback: (1)
 
Join Date: Jan 2007
Location: Sinclair, WY
Posts: 2,393
Received 0 Likes on 0 Posts
Default

Older planes have 72 newer planes have 2.4, I fly both"
Old 02-23-2014, 12:03 PM
  #44  
Rob2160
Senior Member
 
Rob2160's Avatar
 
Join Date: Jun 2010
Location: Sydney, AUSTRALIA
Posts: 4,786
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by TomCrump
To be honest, you may not be able to give them away.
Very true unfortunately. I paid over $700 for my Kraft 7C in 1980.

Found a 5C on Ebay now for $0.99

http://www.ebay.com/itm/Kraft-5c-Ser...item20e0351207
Old 02-23-2014, 12:13 PM
  #45  
coachdavis10
Senior Member
 
Join Date: Aug 2006
Location: Cusseta, AL
Posts: 159
Likes: 0
Received 0 Likes on 0 Posts
Default

Use it... I still put my JR 10X in a couple of planes... Especially a 40 sized that has a small fuse and it's a pain to get mt ATX antennas at 90* angles..
Old 02-23-2014, 02:48 PM
  #46  
lopflyers
Senior Member
My Feedback: (12)
 
lopflyers's Avatar
 
Join Date: Jun 2010
Location: Orlando, FL
Posts: 1,520
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by RCFlyerDan
Retire it and throw it out, as you did with beta and VHS video recorders. Time and technology is moving on.
And glow engines........
Old 02-23-2014, 07:50 PM
  #47  
cap 580
My Feedback: (40)
 
Join Date: Dec 2009
Location: Ainsworth, NE
Posts: 51
Likes: 0
Received 0 Likes on 0 Posts
Default

I agree with Live Wire. 72mhz has saved me a lot of money because of the 2.4 technology. Only sacrifice is the antenna sticking out.
Old 02-23-2014, 09:47 PM
  #48  
GallopingGhostler
 
GallopingGhostler's Avatar
 
Join Date: Oct 2004
Location: Clovis, NM
Posts: 2,301
Received 79 Likes on 62 Posts
Default

We've had some people lose airplanes on 2.4GHz, non-responsive to transmitter signals. Reading between the lines, appeared might be related to their aircraft receiver antenna orientation. I've never lost a plane on 72 MHz. Some of us still fly 72 MHz. Never had antenna problems on 72 MHz.

Although 2.4 GHz overcomes the frequency sharing problem, if fliers are not careful about their installations and other precautions, can experience unintended results.
Old 02-23-2014, 11:32 PM
  #49  
airplanenut1
My Feedback: (19)
 
Join Date: Nov 2004
Location: South Wales, NY
Posts: 25
Likes: 0
Received 0 Likes on 0 Posts
Default

my 72Mhz still works great i'm not putting it down and if i ever did get rid of it i would make sure to give it to some one so they come into the fold and enjoy this hobby like i did when i started
Old 02-24-2014, 04:00 AM
  #50  
sensei
 
sensei's Avatar
 
Join Date: Jul 2002
Location: SAN ANTONIO, TX
Posts: 2,826
Received 17 Likes on 15 Posts
Default

What to do with 72mhz.? I tossed all my old 72mhz. stuff in late 2006 when I purchased my first 2.4 and never looked back. This is a hobby and as most hobbies; their nothing short of a money pits so I have never looked at any of this stuff as an investment; because it's not.

Some clubs won't even let you fly if your not on 2.4 now and many of the larger flying events are the same, no 2.4, no fly... Anyway, that is my take on it.

Bob

Last edited by sensei; 02-24-2014 at 04:06 AM.

Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service -

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.