Return to KLUBNL.PL main page

rsgb_lf_group
[Top] [All Lists]
<prev [Date] next>
[Advanced]
 <prev [Thread] next>

LF: LF SWR Bridge

from [Rob, M0DTS] [Permanent Link][Original]
To: [email protected]
Subject: LF: LF SWR Bridge
From: "Rob, M0DTS" <[email protected]>
Date: Sun, 15 May 2011 11:09:06 +0100
In-reply-to: <D6B1B6FB2BE84EE5A37FB6B8A3522D5A@lindavideo>
References: <[email protected]> <EE1078C1AE1542A39B4A6054378AA79F@lindavideo> <[email protected]> <D6B1B6FB2BE84EE5A37FB6B8A3522D5A@lindavideo>
Reply-to: [email protected]
Sender: [email protected]
User-agent: Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US; rv:1.9.2.13) Gecko/20101207 Thunderbird/3.1.7
Hi All..

I'm trying to put together my 137KHz transmitter after it has gathered dust in the loft for a few years and will hopefully generate some signals again soon..
I'm not so good with this LF so need a bit of help with an swr bridge..  This will stop me blowing FET's this time i hope!

I've seen a couple of designs for an swr bridge and have tried out G0MRF's one here which appears so simple who could go wrong?!

I'm using a 3c90 core,  a very small one (13mm) but i should be able to get the same effect I'm sure,  i just can't get any difference between forward/reflect at all with 50R on the load port..  the only difference i have in my build is the different core size.
I've tried increasing the bifiliar turns but just gave more coupling as you would expect..

I guess I'm just very low on inductance by using the different core so the q is too low and i don't 'see' the dip in reflected signal when tuned?

Any ideas and a simple explanation of how it works would be useful..

Thanks

Rob
M0DTS

[More with this subject...]
<Prev in Thread] Current Thread [Next in Thread>
Previous by Date:  LF: FYI: DK2TX is testing in WSPR_Mode on 137.450 kc, Beckmann, Gerhard
Next by Date:  LF: Re: LF SWR Bridge, James Moritz
Previous by Thread:  Re: LF: Re: VLF - G3XIZ - 14th May 2011, Ken
Next by Thread:  LF: Re: LF SWR Bridge, James Moritz
Indexes:  [Date] [Thread] [Top] [All Lists]