Greetings all.....I sometimes feel like I abuse this forum because I have asked a bunch of question (and received a bunch of help), but I have contributed very little in terms of assistance or supplying information.  As I gain knowledge and proficiency, I hope I can contribute.

Ok.....so my latest abuse is this..... I could not find a specific reference to this so I apologize if it's already been asked and answered.  Ok Ok...I'm getting there.....A bush reached out and grabbed my quad yesterday and in the process, ripped off my VTX antenna. Took me about 3 or 4 minutes to get to it and unplug the lipo.  It was one of those cheapo linear antennas (new ones on order).  It was a 600mw VTX connected to the antenna by about 2 inches of shielded cabling which was left intact.  I now have no video sig at all....even a couple feet from the receiver, nothing, no static, nothing.  There IS power to the board.  What are the chances that the 3 or 4 minutes of running without the antenna fried the VTX?

Pretty likely. But check other wiring first to make sure video feed is intact and all other related wiring to the VTX from the camera is ok.

(18-Apr-2016, 12:50 PM)Hebrews12v2 Wrote: Pretty likely. But check other wiring first to make sure video feed is intact and all other related wiring to the VTX from the camera is ok.

+1

Thanks guys.....that's what I was scared of....was hoping that perhaps the couple inches of cable left intact would have absorbed some of the output and taken some of the strain off the amplifier....sigh....oh well.....another one on the way....

(18-Apr-2016, 01:56 PM)sirdude Wrote: Thanks guys.....that's what I was scared of....was hoping that perhaps the couple inches of cable left intact would have absorbed some of the output and taken some of the strain off the amplifier....sigh....oh well.....another one on the way....

nah, it doesn't work that way unfortunately...
The antenna has to be tuned to the frequency of your VTX is broadcasting, in order to "absorb" the energy... 
in your case the antenna is ripped... so it wasn't "tuned to the 5G8 Frequency any more... energy goes all back to VTX and heat build up! and BOOM!

That's why when using a VTX with a tuned antenna, it gives you good range, and it normally stays cooler as well

(19-Apr-2016, 11:36 PM)Oscar Wrote: nah, it doesn't work that way unfortunately...
The antenna has to be tuned to the frequency of your VTX is broadcasting, in order to "absorb" the energy... 
in your case the antenna is ripped... so it wasn't "tuned to the 5G8 Frequency any more... energy goes all back to VTX and heat build up! and BOOM!

That's why when using a VTX with a tuned antenna, it gives you good range, and it normally stays cooler as well

Yeah....I guess I knew that.  I got my new antenna today and hooked it back up....nothing....even within 6 inches of the receiver.  The VTX still gets hot, just like it always has, but apparently NO output.  New ones arrives tomorrow, if that works the death of the previous one is confirmed.

Well, I guess I got lucky.  Got the new VTX hooked it up and nothing.  Before I ordered it I had looked at all the connections and they appeared fine, but I didn't take the time to ring the circuits out.  I wanted to get another VTX for my next build anyway, so I just ordered another one.  Anyway, when I started checking all the connections I found that the video wire coming of the camera was not connected to the PDB like it had been.  At first gland it appeared to be ok because I had covered t he connection in liquid tape after I soldered it.  It "looked" fine, but checking with a MM verified it wasn't.  Anyway, long story short, I re-soldered it and everything worked fine!  So just for fun I put the old VTX in and tried it....it worked too!!  So, I now have a spare one, or I'll use it on my next build.
Anyway, thanks for all the help/suggestions folks.....as always, very much appreciated!

(22-Apr-2016, 01:37 AM)sirdude Wrote: Well, I guess I got lucky.  Got the new VTX hooked it up and nothing.  Before I ordered it I had looked at all the connections and they appeared fine, but I didn't take the time to ring the circuits out.  I wanted to get another VTX for my next build anyway, so I just ordered another one.  Anyway, when I started checking all the connections I found that the video wire coming of the camera was not connected to the PDB like it had been.  At first gland it appeared to be ok because I had covered t he connection in liquid tape after I soldered it.  It "looked" fine, but checking with a MM verified it wasn't.  Anyway, long story short, I re-soldered it and everything worked fine!  So just for fun I put the old VTX in and tried it....it worked too!!  So, I now have a spare one, or I'll use it on my next build.
Anyway, thanks for all the help/suggestions folks.....as always, very much appreciated!

Sweet! Glad you found the base issue! and on the plus side you have a backup VTX!

I've accumulated some parts like that. I also have a pile of parts that are my "probably still working but replaced to troubleshoot anyways"... parts. One day I'll get around to verifying if they are actually faulty

Yeah......if I had not planned on getting another one anyway, I would have been more careful about troubleshooting the problem before I ordered a replacement, but they way it's working out, all I need is motors, ESC's, camera and frame and I'm ready to start another build. : )