[Moon] Antenne coupler for 70 cm

[Hans van Alphen]

John,

I hope you measured this with the correct source impedance, but I don't 
think that you have done that correctly.

The impedance of the two antenna's coupling point is no longer 50 ohm but 
two 50 ohms in parallel.
To correctly measure the return loss of this you can do two things:
- measure with a impedance of  25 ohm
- measure with a 50 ohm impedance and a quartre wave impedance matching 
network to convert 50 ohm to 25 ohm.

So the measurement you did was not good and therefore the results you 
measured are not strange.

I expect the coupler you have is working fine.

73 and HNY.

Hans PA0EHG
----- Original Message ----- 
From: "John Lambo" <pa7jb at ziggo.nl>
To: <moon at moonbounce.info>
Sent: Wednesday, December 31, 2014 2:25 PM
Subject: [Moon] Antenne coupler for 70 cm


> Hello Lunatics
> Yesterday i made a antenne coupler for my 70 cm systeem with 2 time K1FO
> The first coupler got a Returnloss at 460mhz off -40 db but after i made 
> it a bit longer i do see a RL  off -40 db on 432mhz .
> But now the point.
> After a question  from  Hans PE1CKK to look at the port where i put my 
> antenne i see a RL off -7 db .
> My question is does some one else also measure this and what to do about 
> it ??
> So i made a coupler with on one side there is a N-connector and on the 
> other side 2 times a N-connector.
> Thuse from 50 ohm to 35,34 ohm in a pice off copper pipe  10mm inside and 
> a brass rod off 5,52mm .
> Thank you for reply .
> Wish you all a Happy and healty 2015
>
>
> 73  John  PA7JB
>
>
> PS sorry if this is now all correct English
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