Posts: 183 Threads: 36 Likes Received: 13 in 9 posts Likes Given: 54 Joined: Apr 2020 Reputation: 0 30-Apr-2020, 09:46 AM (This post was last modified: 30-Apr-2020, 06:26 PM by doronba.) HI, My Tinyhawk 2 VTX antenna was hurt, and the signal wire touches the shielding, so I have to replace it. It gonna take too much time to wait for a replacement antenna to arrive here, so I wish to improvise. I have at home some components like a Lollipop antenna, a MCX male to RP-SMA cable, the original antenna, with the hurt area in the middle of it (I am sorry for not finding the right word for that area, English is not my native tongue). Here is a pic of what I have : https://photos.app.goo.gl/gRR8eXRgDJJRgyCdA Any ideas of how to get the job done ? I have been thinking of taking the rp-sma connection off the lollipop antenna, take the rp-sma off the cable, and connect them (will it work at all ? Is there a way to maintain the shielding effect in this way ?), and then, take the MCX off, and solder tis edge to the VTX board. Can it work ? Any better solutions ? waiting for shippmetns from bangood will take at least 2 months... Doronba ![[-]](https://intofpv.com/images/collapse.png) • Posts: 21,416 Threads: 595 Likes Received: 9,039 in 6,690 posts Likes Given: 1,428 Joined: Jun 2018 Reputation: 796 30-Apr-2020, 10:03 AM (This post was last modified: 30-Apr-2020, 10:04 AM by SnowLeopardFPV.) I can't see what you have working too well TBH. If you were to hack the SMA connector off the end of the Lollipop then the gauge of the coaxial on it is probably too heavy to solder directly to the VTX. If you make use of the pigtail then the soldering is easier but you are then carrying around a load of extra bulk and weight of the SMA connectors and wiring, plus you need to find somewhere to strap/mount them on the TinyHawk so not an easy task. Are there any RC hobby shops in Israel? I see this place so it might be worth giving them a call and seeing if they have anything: https://zdrone.co.il • Posts: 183 Threads: 36 Likes Received: 13 in 9 posts Likes Given: 54 Joined: Apr 2020 Reputation: 0 30-Apr-2020, 10:13 AM (This post was last modified: 30-Apr-2020, 10:15 AM by doronba.) Thats the problem Leopard, any 5.8 products can not enter here formally, so I have to improvise. I have already talked to them today - they can't help they prefer build ready to fly racers (w/out the VTX). I was thinking of cutting in the marked places in the pic. : https://photos.app.goo.gl/iR7nr4SUuK31FT3u6 Soldering the edge to the VTX - I believe that I will manage to do it. My main question is : is it possible to connect the pig tail to the Lollipop, with soldering ? I have'nt done such a thing before, and I don't know if it is even possible (shield to shield, signal to signal) About connecting it to the Tinyhawk, I have already some ideas, that's my last problem right now. • Posts: 21,416 Threads: 595 Likes Received: 9,039 in 6,690 posts Likes Given: 1,428 Joined: Jun 2018 Reputation: 796 30-Apr-2020, 10:18 AM (This post was last modified: 30-Apr-2020, 10:18 AM by SnowLeopardFPV.) Yes, you can do what you are proposing. It's worth a shot. How well it will work is to be seen but nothing ventured, nothing gained  At the end of the day, the pigtail is just a small gauge coaxial cable with braided shielding and a centre signal wire just like the dipole antenna. So strip it back and solder it to the VTX in exactly the same way as the dipole is soldered (coax shielding to the ground pad and centre signal wire to the other pad). • Posts: 183 Threads: 36 Likes Received: 13 in 9 posts Likes Given: 54 Joined: Apr 2020 Reputation: 0 Going to give it a shot....
Holyland - Living in in imaginary island, separated of the rest of the world....
Thanks man,
I will update.
BTW, if you read my last post, it seems that the problems were from the faulty antenna (which I am going to fix now) and also might be du the an ugly soldering of the main power cables - going to fix that also later... • Posts: 21,416 Threads: 595 Likes Received: 9,039 in 6,690 posts Likes Given: 1,428 Joined: Jun 2018 Reputation: 796 OK. I didn't realise that 5.8GHz was banned in Israel, but I just read about it  It's the join between the pigtail coax and the Lollipop coax that is going to be tricky, and that could be critical to the signal. Ideally you want a complete ring of shielding around the whole centre signal wire but that is going to be difficult with having to soldering two different gauge wires together. You could wrap some tin foil around that section and then cover it in heat shrink or insulation tape, but how well that will work or whether that has a detrimental effect on the overall signal I don't know. I'm not an antenna expert unfortunately. So it will be an experiment of trial and error. • Posts: 183 Threads: 36 Likes Received: 13 in 9 posts Likes Given: 54 Joined: Apr 2020 Reputation: 0 30-Apr-2020, 01:37 PM (This post was last modified: 30-Apr-2020, 01:42 PM by doronba.) Done, and succesfully (but different than what I planned originally) What I did, was : cutting the pig tail of both sides, one side connected carefully to the vtx, other side was connected to the bolbous part of the original antenna (the effective part), in the pics you can see the new combined antenna : https://photos.app.goo.gl/xYeeKXwn1Bhag3cr9 the process : https://photos.app.goo.gl/aPXS9BJ1TKcJA9yt6 it works, and I am very excited - it was my first nano soldering of micro parts, and everything worked !!! now, I would like to re-solder the main power cables, as the XT30 is crooked of previous soldering, and the cables seem burned. my question, is, should the ground leg of the VTX be bridged with the main ground cable or not ? Its hard to see, as the area is very dirty due to previous soldering. currently, I checked conductivity, and they are connected, but should it be like that ? or the ground leg ov the VTX gets its ground from some other place in the circuit ? Its hard for me to figure this out. Iam terribly sorry for the pics quality, I have to hold the torch in one handn the camera in the other hand, and somehow press the button.... LOL Posts: 21,416 Threads: 595 Likes Received: 9,039 in 6,690 posts Likes Given: 1,428 Joined: Jun 2018 Reputation: 796 Well done. It looks like you made a really nice job of that. I previously thought you were intending to use the head of the Lollipop but I see what you've done done is effectively created your own new dipole antenna instead.
Ground is ground. All ground points connect to to a common ground plane. Whether the ground leg of the VTX is bridged with solder to the main ground cables matters not. If it wasn't, they would still be connected via the common ground plane. Bridging solder to the VTX ground pin with solder will just make for a stronger mechanical connection because the ground cable won't then just be attached to a pad that could easily be ripped off. So bridging solder to a physical solid pin creates some additional mechanical strength for the XT30 pigtail. • Posts: 183 Threads: 36 Likes Received: 13 in 9 posts Likes Given: 54 Joined: Apr 2020 Reputation: 0 Thanks Loepard, You understood correctly, What I was planning was indeed use the lollipop, but, after cutting its rp-sma connector, and soldering it to the pig tail, I checked conductivity, and at the first time it was ok, I then, added some more solder, and it probably melted the shrink that I put to separate the signal wire from the outer part, and I gave up on the lollipop direction, and went for a more flexible idea, uising the other active antenna part. here are some pics for inspiration : hehehehe https://photos.app.goo.gl/ve54cAzUNCD1BebUA I am really appreciating your support along these long 3 days of trial and error, hpoefuly tomorrow, I will be already flying the little beast :-) Doron • |
