Maybe flying with a sorter FM antenna
12-06-2021, 01:43 AM
#1
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Join Date: Aug 2005
Posts: 304
Maybe flying with a sorter FM antenna
I still have some RC electric airplanes on the futaba FM transmitters , I noticed the last telescoping end was so loose that when flying it drops down back into the next section and just stays there , I cant tight it ,I was thinking od roughing it up with a little sand paper. well anyway it dosent make a difference when flying even though the full rod that drops is about 5 " any one ever have this happen ? and is it OK
12-06-2021, 06:50 PM
#3
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I had similar with an old Futaba M series 35Mhz .....
Most antenna like that - the telescoping sections have 2 brass tabs that sit around the end of the rod ... when rod is pulled up - the top of tabs hits the curved in top of preceding and stops it coming all way out. The tabs also provide the friction to keep rod extended.
If you can remove the screw base of the antenna (usually Futaba have a self-tapper screw in centre) ... unscrew the screw .. remove base and you can then carefully drop out that top section while keeping all other sections in place. You will probably find that the brass tabs are not in place. I managed to put back in place - rod and tabs carefully slid back in .. base refitted ... Fixed. BUT not long after - it happened again - basically the tabs are loose and fall of again. Second time - I just took pair of crimp pliers and crimped that top section permanently extended. But all other sections still telescoped.... note - I made sure that second from top- section that I crimped to hold top section could not be fully telescoped to avoid it getting stuck etc.
Most antenna like that - the telescoping sections have 2 brass tabs that sit around the end of the rod ... when rod is pulled up - the top of tabs hits the curved in top of preceding and stops it coming all way out. The tabs also provide the friction to keep rod extended.
If you can remove the screw base of the antenna (usually Futaba have a self-tapper screw in centre) ... unscrew the screw .. remove base and you can then carefully drop out that top section while keeping all other sections in place. You will probably find that the brass tabs are not in place. I managed to put back in place - rod and tabs carefully slid back in .. base refitted ... Fixed. BUT not long after - it happened again - basically the tabs are loose and fall of again. Second time - I just took pair of crimp pliers and crimped that top section permanently extended. But all other sections still telescoped.... note - I made sure that second from top- section that I crimped to hold top section could not be fully telescoped to avoid it getting stuck etc.
12-07-2021, 02:55 PM
#4
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Thread Starter
Join Date: Aug 2005
Posts: 304
antenna loose on FM 72 Mhz transmitter
Originally Posted by solentlife
I had similar with an old Futaba M series 35Mhz .....
Most antenna like that - the telescoping sections have 2 brass tabs that sit around the end of the rod ... when rod is pulled up - the top of tabs hits the curved in top of preceding and stops it coming all way out. The tabs also provide the friction to keep rod extended.
If you can remove the screw base of the antenna (usually Futaba have a self-tapper screw in centre) ... unscrew the screw .. remove base and you can then carefully drop out that top section while keeping all other sections in place. You will probably find that the brass tabs are not in place. I managed to put back in place - rod and tabs carefully slid back in .. base refitted ... Fixed. BUT not long after - it happened again - basically the tabs are loose and fall of again. Second time - I just took pair of crimp pliers and crimped that top section permanently extended. But all other sections still telescoped.... note - I made sure that second from top- section that I crimped to hold top section could not be fully telescoped to avoid it getting stuck etc.
Most antenna like that - the telescoping sections have 2 brass tabs that sit around the end of the rod ... when rod is pulled up - the top of tabs hits the curved in top of preceding and stops it coming all way out. The tabs also provide the friction to keep rod extended.
If you can remove the screw base of the antenna (usually Futaba have a self-tapper screw in centre) ... unscrew the screw .. remove base and you can then carefully drop out that top section while keeping all other sections in place. You will probably find that the brass tabs are not in place. I managed to put back in place - rod and tabs carefully slid back in .. base refitted ... Fixed. BUT not long after - it happened again - basically the tabs are loose and fall of again. Second time - I just took pair of crimp pliers and crimped that top section permanently extended. But all other sections still telescoped.... note - I made sure that second from top- section that I crimped to hold top section could not be fully telescoped to avoid it getting stuck etc.
12-07-2021, 03:37 PM
#5
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Join Date: Oct 2010
Location: Ex UK Brit now in Latvia west coast - Ventspils
Posts: 12,909
Originally Posted by Rhondas
thank You Il atempt it I think my bottom brass screw is pressed in I don't see a set screw ae you saying maybe it will unscrew the whole brass piece
The best solution is to either crimp the top section fixed in place ... or buy a new antenna of suitable length and with screw base .... replace the antenna .... no need to pay Futaba prices ... just check full length and lower section diameter needed and eBay / radio shop etc. will have for small money.
