Can anyone kindly advise?
I 'retroed' an old 2.4 gh Radiolink (10+ yrs?) to make it work like a reeds set and put it in an ali box (Thanks Martin for the advice replacing pots with resistors)
I'm now having serious range issues - 4ft
The case is bent aluminium with 3 d printed sides
The new layout runs the antenna cable near the other electrics (reed switches) - not near power supply though
I unsoldered the antenna from the board to run it through a hole in the casing
Because it was close to the pots I shrouded the antenna wire inside the tx using a bit of coaxial cable shroud and enclosed that in heat shrink tubing - keep it neat(ish) and avoid possible grounding
I'm pretty sure the solder join is good.
I didn't run tx without an aerial
Got to the slope with it in the Zeitgeist - and obviously didn't fly
Any genius thoughts?
Thanks
Nick
2.4 conversion - range problem
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Re: 2.4 conversion - range problem
I suspect this is the heart of your problems! Soldering at these sort of frequencies is a bit of a black art - especially with such thin wires!I unsoldered the antenna from the board to run it through a hole in the casing
The ground (outer) sheath is just as important as the inner - which carries the signal. It is very easy to leave a whisker of wire or solder bridging the lands. The exposed portion of the inner needs to be as short as possible. Even a blob of excess solder on one of the joints can be detrimental.
Personally, I will only unsolder and resolder leads at these frequencies when there is no other alternative, and will move heaven and earth to find an alternative!
It will be difficult to diagnose without some fairly sophisticated test equipment . Ideally you need an RF power meter that you can connect in place of the aerial to see what is actually arriving at the aerial. I use one of these: https://www.hobbyrc.co.uk/immersionrc-rf-power-meter-v2
Beware of cheap ones from the bay of evil! They may not provide the correct 50 ohm termination at UHF frequencies! I've run in to this problem even at 459MHz, where a 50 ohm termination was anything but at that frequency!
A spectrum analyzer is also very useful, but ones that operate at this sort of frequency are very expensive - even old second-hand ones!
Best of luck!
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Pete
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Re: 2.4 conversion - range problem
What 2,4 GHz module are you running?
As Pete mention proper wiring is a must and wiring can include twisted wires, ferrites, low ESR caps, inductors, shielding, positioning etc. I know by experience that many of the processor we use in our conversions i.e. ATmel Mega 328P/168PA are quite sensitive for RF interference which often shows in extreme low range if any.
Any pictures?
As Pete mention proper wiring is a must and wiring can include twisted wires, ferrites, low ESR caps, inductors, shielding, positioning etc. I know by experience that many of the processor we use in our conversions i.e. ATmel Mega 328P/168PA are quite sensitive for RF interference which often shows in extreme low range if any.
Any pictures?
Cheers,
Tobe
Tobe
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Re: 2.4 conversion - range problem
I also suspect a soldering problem where the co-ax antenna cable attaches to the PCB. I've repaired quite a few receivers for club members who have managed to pull the whisker antennas off - either in a crash or with careless handling: it's always a nightmare and I always insist on them doing extensive range checks before flying again, even though I do the soldering as carefully as possible, using a tiny soldering tip, good lighting and magnification.
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Re: 2.4 conversion - range problem
Thanks all
Will invent time machine to avoid having unsoldered antenna...
I unsoldered initially to route through hole in case - could actually have left intact with a bit of thought
This the Tx - which has worked well for years = 'vintage' of a sort
I have lots of receivers for this tx - hence the interest
I haven't actually soldered the coax to the PCB... just fairly tight shroud round almost all of the cable inside the tx (pulled tight to be close around cable, heatshrink around it to prevent and contact with case, etc
Perhaps unsoldering and having cabling outside tx and see what range is a sensible next step
Cable inside tx is fairly long - didn't want to shorten in case had to rearrange components as thought proximity to reed switches might be a problem
I'll remove shroud, put cable outside tx and see what happens
I'll check soldering
Thanks all
I have another radiolink 4 ch tx (more primitive, no lcd) if all else fails will tray that
Best
Nick
Will invent time machine to avoid having unsoldered antenna...
I unsoldered initially to route through hole in case - could actually have left intact with a bit of thought
This the Tx - which has worked well for years = 'vintage' of a sort
I have lots of receivers for this tx - hence the interest
I haven't actually soldered the coax to the PCB... just fairly tight shroud round almost all of the cable inside the tx (pulled tight to be close around cable, heatshrink around it to prevent and contact with case, etc
Perhaps unsoldering and having cabling outside tx and see what range is a sensible next step
Cable inside tx is fairly long - didn't want to shorten in case had to rearrange components as thought proximity to reed switches might be a problem
I'll remove shroud, put cable outside tx and see what happens
I'll check soldering
Thanks all
I have another radiolink 4 ch tx (more primitive, no lcd) if all else fails will tray that
Best
Nick
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- Joined: 19 Jun 2019, 04:09
Re: 2.4 conversion - range problem
By "pictures" pretty sure Tobe was referring to the new layout internals etc.
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- Posts: 92
- Joined: 19 Dec 2018, 20:39
- Location: Camberwell london
Re: 2.4 conversion - range problem
Many thanks for all your help
I have had some time and got back to the project
My fault (not a surprise)
The aerial required very careful soldering and I had assumed it needed to be soldered to a larger area than turned out to be the case
I re soldered and range certainly good for 50 yards at least - and will do a proper range check before committing aviation
Going to be used in Zeitgeist and with W of Oz with a non lifting tailplane
It'll be up Cook Peak and single channel too demanding for me but reeds will be ok hopefully - most slopes are spine backed
I have had some time and got back to the project
My fault (not a surprise)
The aerial required very careful soldering and I had assumed it needed to be soldered to a larger area than turned out to be the case
I re soldered and range certainly good for 50 yards at least - and will do a proper range check before committing aviation
Going to be used in Zeitgeist and with W of Oz with a non lifting tailplane
It'll be up Cook Peak and single channel too demanding for me but reeds will be ok hopefully - most slopes are spine backed