72 MHz

This is the place to hang and talk.

72 MHz

PostPosted: Sun Nov 29, 2020 5:00 pm

Guys, went flying with my dad today. He has always religiously used 72mhz Futaba with no issues. FM ch29 to be exact. He had a dead stick landing today. I walked out to grab his plane less than 75 yards. When I got there I noticed right away the ailerons were jittering roughly 1/8 . The antenna was fully extended! Upon further inspection all of his plans on 72 are experiencing this problem. If you are still on 72 it maybe worth while to preform a good radio check. To be honest we only did his once every 4th or 5th trip. Never seen anything like it.
Heinz57
Pro Bro
 
User avatar
 
Posts: 297
Joined: Tue Jan 28, 2020 7:33 am
Location: Toano, VA

Remove Advertisements

TheProfileBrotherhood.com
Advertisement
 

Re: 72 MHz

PostPosted: Mon Nov 30, 2020 8:38 am

If he's still using NiCd, look at that. Low voltage may be the cause.
"That can't be un-fucked" - Clay @Nash 2012
Fly like you have no tomorrows.

*Asshole Disclaimer*
If you think you have been offended, please unread this post.
Mike
ThumbSkull
Pro Bro
 
User avatar
 
Posts: 8308
Joined: Mon Feb 11, 2008 11:39 pm
Location: Greenwood, IN

Re: 72 MHz

PostPosted: Mon Nov 30, 2020 10:37 am

Or if you switched out to LiFe batteries, some of the old JR and Futaba servos didn’t like a fully charged 5 cell nicad... once you got the first flight in, the servos would settle. Also check e tensions for corrosion, if it was only the ailerons on all planes, I would suspect something else. The pot on the aileron gimbal could be getting worn out.
Motowncali
Pro Bro
 
User avatar
 
Posts: 4327
Joined: Thu Oct 17, 2013 4:17 pm
Location: Crowley, TX

Re: 72 MHz

PostPosted: Mon Nov 30, 2020 1:01 pm

aileron flutter ruining the pots.
Everyone's entitled to their opinion.

No matter how wrong they are.
Wild Fred
Pro Bro
 
User avatar
 
Posts: 16054
Joined: Fri Jun 04, 2004 10:56 am
Location: sitting on the seawall fishing

Re: 72 MHz

PostPosted: Mon Nov 30, 2020 5:28 pm

have you had time to check it out,at home. if all planes did it,not the planes. transmitter or interferance. has unit fallen down. cystals are weak point of fm. transmitter may have shifed frec slighty. we wait for updates,bros waking up,lots new post.
sparkplug
Pro Bro
 
Posts: 952
Joined: Fri Apr 17, 2020 10:45 pm
Location: 1 mile from lake Thurmond 15miles north of augusta ga.

Re: 72 MHz

PostPosted: Mon Nov 30, 2020 5:38 pm

there's absolutely nothing wrong with 72mhz. Still works just fine. Just make sure your batteries and connections are solid and you should have a worry free experience, seeing as most have switched to 2.4
Tim
tcipolla
Pro Bro
 
User avatar
 
Posts: 3045
Joined: Wed May 19, 2010 4:49 pm
Location: Shiloh, IL

Re: 72 MHz

PostPosted: Mon Nov 30, 2020 7:23 pm

To be a little more specific, the radio is a 6ex pcm that I ordered for him from tower about 10 years ago just before we got out of flying. I’d say less than 30 hours on it. He uses 2600 mah nimh packs at 4.8v “4 cell” all purchased about 5 months ago. He does have another Ch29 Futaba transmitter we can test with. The incident occurred on his first flight of the day. I’m really not a fan of nimh or the resistance they make. But being older equipment, I’m not sure if it would be happy on A123 voltage. Also, I didn’t mention the flutter was non existent in close range. If it was the radio, would it do it all the time? I’m not by any means trying to bad mouth 72 as it has served well for many years. Just wanted to note what we experienced. Honestly I can’t believe we didn’t loose the plane. Just wanted to encourage bros still using it to preform a good radio check.

Our location could possibly play a roll. I retired my 72 stuff in 2008. One morning I fired up my radio in the Pitts and another club member was experiencing interference/bleed over from my radio. We use and still have a peg board. My radio was a old AM ch18 conquest. His was a 6ex-pcm FM ch36 if I recall.
Heinz57
Pro Bro
 
User avatar
 
Posts: 297
Joined: Tue Jan 28, 2020 7:33 am
Location: Toano, VA

Re: 72 MHz

PostPosted: Mon Nov 30, 2020 7:31 pm

Could be interference from an outside source. If you have an extra 2.4ghz RX, maybe install it and take it to the field and see if you have the same issue. That would at least rule out a radio issue.
Tim
tcipolla
Pro Bro
 
User avatar
 
Posts: 3045
Joined: Wed May 19, 2010 4:49 pm
Location: Shiloh, IL

Re: 72 MHz

PostPosted: Mon Nov 30, 2020 7:41 pm

fm is much better than am. i have had no problems at all. i use nimh batterys in plane,4.8 v and trans. recheck at house,then try no2 trans. i have bunch jr fm,all work great,on nimh,at long range.
sparkplug
Pro Bro
 
Posts: 952
Joined: Fri Apr 17, 2020 10:45 pm
Location: 1 mile from lake Thurmond 15miles north of augusta ga.

Re: 72 MHz

PostPosted: Mon Nov 30, 2020 10:54 pm

Just spit balling here but I would check the internal antenna connection. It is also possible that there is a new source of interference where you fly. The servos in my AM plane jitter when close to town but is very smooth and steady when many many miles away from town and nothing is within sight.
Mojo 60 in construction
1-1/2” shorty
Peace and chicken grease
Montana3D
Pro Bro
 
Posts: 134
Joined: Mon Jul 25, 2016 8:58 am
Location: Montana

Re: 72 MHz

PostPosted: Tue Dec 01, 2020 12:09 am

Just a thought i picked up. the small, flat , washer size capastiors,i killed that one,slowly dry out in el stuff. Someone way smarter than me might tell us about it. Could this be why a radio gets out of tune.
sparkplug
Pro Bro
 
Posts: 952
Joined: Fri Apr 17, 2020 10:45 pm
Location: 1 mile from lake Thurmond 15miles north of augusta ga.

Re: 72 MHz

PostPosted: Fri Dec 04, 2020 6:23 pm

did you have time to look at that radio any more.
sparkplug
Pro Bro
 
Posts: 952
Joined: Fri Apr 17, 2020 10:45 pm
Location: 1 mile from lake Thurmond 15miles north of augusta ga.

Re: 72 MHz

PostPosted: Sun Dec 06, 2020 5:53 pm

Plug- unfortunately not yet. Was so tied up this weekend, we couldn’t make it to the flying field :( I’ll definitely post results :tu:
Heinz57
Pro Bro
 
User avatar
 
Posts: 297
Joined: Tue Jan 28, 2020 7:33 am
Location: Toano, VA


Return to Pro Bro General Chat

Who is online

Users browsing this forum: Heinz57, Wild Fred and 6 guests