RF beacon question - Page 44 - RC Groups
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Jul 08, 2012, 12:37 AM
Registered User
kempo's Avatar
Quote:
Originally Posted by fmkit
in Europe use PMR (446MHz) and LPD (433)
beacon's menu system has no limits - you can set 240-930
if out 400-470MHz RF much attenuated by LowPassFilter
if you're good with SMT rework bypass the filter
all walkie-talkies fall into beacon filtered band and no mod is needed.

NKT-3R was good 3 years ago, today for the same money one can buy dual-band VHF/UHF maybe even more compact.
Thank you fmkit for the clarifications.

The option to buy a NKT-3R or a dual-band VHF/UHF it is ok, but on the same money i found a pair of walkie talkies : http://www.ebay.co.uk/itm/Binatone-L...#ht_1461wt_905 .

I will choose the pair of walkie talkies because i can use them in other purpose (when i go fishing).

If you say that the pair of walkie talkies are ok, i will go with them.

Thank you.
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Jul 08, 2012, 07:25 AM
fast
fmkit's Avatar
Quote:
Originally Posted by kempo
Thank you fmkit for the clarifications.

The option to buy a NKT-3R or a dual-band VHF/UHF it is ok, but on the same money i found a pair of walkie talkies : http://www.ebay.co.uk/itm/Binatone-L...#ht_1461wt_905 .

I will choose the pair of walkie talkies because i can use them in other purpose (when i go fishing).

If you say that the pair of walkie talkies are ok, i will go with them.

Thank you.
sure these Binatone radios will work, I took one of these apart and noticed better build compared to average american FRS radio, there was RF front-end SAW filter and crystals (European standards are tough!) , these radios a bit more sensitive compared to chinese transcievers and mute works very good, my NKT picks noise off adjacent channels (low selectivity). Wikipedia says range of 536km was recorded using PMR radios.
Jul 09, 2012, 12:24 AM
FPV in Hawaii
iskess's Avatar
No removable antenna however. I'm still searching for the perfect UHF beacon tracker, which includes an affordable price. My Realistic police scanner seems to have terrible range. I couldn't hear it beyond 1km. What should I expect Peter?
Jul 09, 2012, 04:11 AM
FPV in Hawaii
iskess's Avatar
Quote:
Originally Posted by iskess
I just popped open one of those ubiquous AA battery powered Eflight 1s chargers and was pleased to see that it contains a very small PCB, actually 2. See photos. Sorry about the blurry images from the iphone.
Attachment 4911732
Attachment 4911736

This is the PCB for the 6v in jack. I wonder why it is attached to both 4 AA's for 6v, and also 3 of the AA's for 4.5v. It doesn't even need the AA's if using the jack. The yellow wire goes to the 3rd battery to get 4.5v.
Attachment 4911777

This seems like it would be easy to install in my airplane, it even has the LED that could show when the 1s is charging.
Should I hook the main ubec to the where the AA's went, or the DC jack? I don't understand what the second PCB that holds the jack is doing. Why does it look at both 6v and 4.5v from the AA's?

What do you guys think, will this work?
I finished the eflight 1s charger hack tonight. It turns out that the 4.5 wire was just for the charging LED. I kept the LED so i could mount it outside the fuselage to monitor that charge state of my 1s beacon battery. I used the external power jack PCB rather than the AA battery leads because it had a diode. The 1s battery could flow back into AA batteries, but not the 6v jack. I clipped the external power PCB very small so it only included the 2 diodes, the big black one to drop voltage to 4.5 for the LED, and another tiny one to keep the circuit unidirectional.
The charger plugs into the receiver providing the 5-6v. The other end attaches to the 1s, and the beacon. The 1s is now automatically being charged whenever the plane is powered up. The beacon is powered by the battery which would continue to be charged by the BEC long after the crash, assuming the big battery stayed attached to the plane. If not, the 1s would be certain to have a 100% charge when it starts it's duty. One caveat, the beacon will not run off the charging circuit alone, the 1s must be attached to activate the flow of electricity through the charger.

FMKit, yours will be so much cleaner, lighter, and more functional. I only offer this as a proof of concept to motivate your creative genius. I'm sure you already have several ideas of how to make this better. Ideally it would monitor a PWM output and be activated by a fail safe position, like RTH. Name: ImageUploadedByTapatalk1341824605.394176.jpg
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Jul 10, 2012, 06:12 PM
Quote:
Originally Posted by iskess
No removable antenna however. I'm still searching for the perfect UHF beacon tracker, which includes an affordable price. My Realistic police scanner seems to have terrible range. I couldn't hear it beyond 1km. What should I expect Peter?
Its illegal to sell one of the new radios with removable antennas, but you can open it up and make the antenna removable with an xacto knife (cutting the plastic around the antenna, leave screw out), thats what I did... SHHhhhhhhhhh, dont tell anyone, lol.
Jul 11, 2012, 02:40 AM
Registered User
joel0407's Avatar
Hey KillerCut. I couldn't quote your post for some reason.

I'm just wondering why it's illegal to sell a radio with a removable antenna? I would think it more likely the manufacture would make it not removable because some transmitters can be damaged by transmitting without a load (antenna) attached.
Jul 11, 2012, 08:50 AM
yea, i should have mentioned that too. do not transmit with your radio without the antenna, but you can receive no problem.
Jul 11, 2012, 09:21 AM
You can't take the sky from me
Rastislavko's Avatar
In the Europe using PMR radios (446 MHz) with removable antennas is really prohibited. As well as using higher output than 500 mW. With LPD (433 MHz) it's even worse - the maximum legal output is only 10mW. In both cases you can use only the internal (non-removable) antennas. For higher output or removable antennas you need radio amateur licence... This is why all walkie-talkies are with fixed antennas.

PS: This is why I'm also looking for good radio outside the EU, best with BNC antenna connector, can anyone suggest? :-)
Jul 11, 2012, 01:52 PM
FPV in Hawaii
iskess's Avatar
Quote:
Originally Posted by Rastislavko
In the Europe using PMR radios (446 MHz) with removable antennas is really prohibited. As well as using higher output than 500 mW. With LPD (433 MHz) it's even worse - the maximum legal output is only 10mW. In both cases you can use only the internal (non-removable) antennas. For higher output or removable antennas you need radio amateur licence... This is why all walkie-talkies are with fixed antennas.

PS: This is why I'm also looking for good radio outside the EU, best with BNC antenna connector, can anyone suggest? :-)
FMKit mentioned earlier that the SMA connector is less RF leaky than the BNC connector, so better for fine tuning the beacon location with the antenna removed.

I too am hoping someone can locate the best radio for this purpose.
I am suprised how quiet this thread is. It used to be so active before I showed up. Is is something I said, do I have BO?
Jul 11, 2012, 03:13 PM
Suspended Account
Quote:
Originally Posted by Rastislavko
In the Europe using PMR radios (446 MHz) with removable antennas is really prohibited. As well as using higher output than 500 mW. With LPD (433 MHz) it's even worse - the maximum legal output is only 10mW. In both cases you can use only the internal (non-removable) antennas. For higher output or removable antennas you need radio amateur licence... This is why all walkie-talkies are with fixed antennas.

PS: This is why I'm also looking for good radio outside the EU, best with BNC antenna connector, can anyone suggest? :-)
Sounds like you may be looking for something like I have for sale?

http://www.youtube.com/watch?v=0B535...ature=youtu.be
Jul 11, 2012, 08:56 PM
FPV in Hawaii
iskess's Avatar
Quote:
Originally Posted by goldsworthy
Sounds like you may be looking for something like I have for sale?

http://www.youtube.com/watch?v=0B535...ature=youtu.be
What are you selling?
What is the point of the video? Just that you can take the antenna off?
I have one of those Realistic police scanners and looking for something better. My range sucks.
Jul 11, 2012, 09:01 PM
FPV in Hawaii
iskess's Avatar
Peter,
My beacon activated while I was flying today and the good new is it didn't affect the RSSI on my Dragon Link at all. The really bad news is that my range was so terrible I couldn't hear anything beyond about 300 meters away while airborne.
Either my Realistic police scanner really sucks, or something is wrong with your beacon.
What range should I expect?
Are you still here?
Jul 11, 2012, 09:18 PM
fast
fmkit's Avatar
I've seen pair of Uniden GMR322 at WalMart for $14, these are as sensitive as $100 HAM-radio. Atleast antenna is resonating spot-on FRS channels unlike your old police scanner that has unknown antenna. Try different radio, while airborne all 3 tones should sound clear within 300m , w/beacon on the ground range drops 5 times,
Jul 11, 2012, 11:21 PM
-NEFPV-
Quote:
Originally Posted by fmkit
I've seen pair of Uniden GMR322 at WalMart for $14, these are as sensitive as $100 HAM-radio. Atleast antenna is resonating spot-on FRS channels unlike your old police scanner that has unknown antenna. Try different radio, while airborne all 3 tones should sound clear within 300m , w/beacon on the ground range drops 5 times,
I can hear all beacons for about 2500 ft. I lost the tri in weeds one day. I could not find it. I was on the complete other side of the field and getting all the beeps (500ft away) and I only found it by accident while crossing the field to leave.
Jul 11, 2012, 11:23 PM
-NEFPV-
Quote:
Originally Posted by iskess
I finished the eflight 1s charger hack tonight.
great idea! I think this would work with the the USB charger that came with my Syma 107 heli. I use a syma lipo to run my beacon and it would be awesome to be able to keep it topped up in flight. Although I fear this would increase my chances of puffing the cell.


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