Jump to content
Sign in to follow this  
ahab

Hong Kong 1.2 GHZ system

Recommended Posts

Hi Guys

I have just ordered from Maplins (UK) a Nikkai frequency counter and signal strength indicator.

My question is :

Once I have determined the actual frequency of my Hong Kong setup how do I determine the length the whip on the TX should be (at the moment it sticks 110mm out of the case.)

It would appear that the Nikkai counter shows signal strength as a bar graph, can I keep chopping bits off the whip until the graph shopws the highest output or am I missing something and being really dumb here.

I have some RG174 coax to make a ground plane ant but will this be too flimsy at nearly twice the size of a 2.4 GHz groundplane ant at 3cm.?

sorry to be a pain but I seem to be going arond in circles and getting nowhere

I also Have a TONY HILL 2.4GHz system from the UK ( Well RX actually, the TX got splattered.)

I took off the "stick with square elements"(Yagi?) of the RX as this was far too flimsy and too directional anyway and fitted a goof proof patch ant to the RX

I could not get hold of SMA connectors for love nor money so I have used an F type plug connector on the patch and an F socket to the RX case with about 1inch of coax to reach from rx module to socket

The F plug I used was the screw in type and I soldered the pug body to the brass reflector and a piece of copper wire is soldered to the element and goes straight into the hole in the socket . Does this sound OK?

I have another 2.4 GHz tx from "airwave" but I cannot find out the output or anythinig else about it It has a label on it which reads 610T006911 does this mean anything to anyone?

any help would be much appreciated by this Newbie Limey

Ahab (coz I'm havin' a "whale" of a time"

Edited by ahab

Share this post


Link to post
Share on other sites
I could not get hold of SMA connectors for love nor money so I have used an F type plug connector on the patch and an F socket to the RX case with about 1inch of coax to reach from rx module to socket
At 1.2GHz or so, the F is fine. At 2.4Ghz, they will attenuate your signal. If your system is 2.4Ghz, do not use F connectors.

Share this post


Link to post
Share on other sites

Ok thank for the info

I'll take the F off the 2.4 RX can I just solder a V short length of RG174 from the module to the patch?

Ahab

Share this post


Link to post
Share on other sites
can I just solder a V short length of RG174 from the module to the patch?

The success of the patch includes not using coax. What is the Rx's factory supplied connector? Use the mate that matches it.

Share this post


Link to post
Share on other sites

The factory supplied ant was a piece of glass fiber tube about 6" long with 7 or 8 square copper elements glued to it in a line .

a piece of coax led from the module to the 2nd element in the line so there was no connector at all

Share this post


Link to post
Share on other sites

Then just use the factory supplied coax and solder it to the Patch. Be careful of heat -- it can distort the coax's poly dielectric material, which is not a good thing to do.

Share this post


Link to post
Share on other sites

Ok thanks

I will have to replace the factory coax as I cut it so short will RG174 be ok

Share this post


Link to post
Share on other sites

ok

just done that I will let you know how it went

Thanks again

Share this post


Link to post
Share on other sites

I dont think I mentioned it but I picked up a pair of Olympus eyetrek gasses on Ebay for £77 absolutely brilliant. Have just got back from flying and tried out my Hong Kong 1.2Ghz gear. I built a scaled up Goof Proof Patch and mounted it on to the RX with an F connector ( from what I have read I guessed that my 1.2 set was probably 1.1 so I scaled the patch to that size)

The tx ant was 110mm long so I lopped it to 65mm The results were astounding !!! Flying a 1/5 scale stearman a long way off (400m?) I had some dropouts and the cmos camera quality was crud but heck it worked

I had the camera facing forwards attached to a cabane strut with the pp3 taped to the strut and I viewed through the eye treks while my mate flew then we swapped over.

The eye treks do need 240V but I have an inverter so it was portable

We are having a bit of a vibration problem as the camera was hastily fitted and may not have been shock proofed enough , any ideas on camera mounting.

The next trial will be with my 5m scale slope soarer ASW17 . I will attempt to fly the beast through the eye treks with my mate on a buddy lead for safety.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this  

×