Return to KLUBNL.PL main page

rsgb_lf_group
[Top] [All Lists]

LF: A simple ULF/MF diplexer?

To: [email protected]
Subject: LF: A simple ULF/MF diplexer?
From: DK7FC <[email protected]>
Date: Fri, 26 Aug 2016 13:46:23 +0200
In-reply-to: <[email protected]cal>
References: <[email protected]cal>
Reply-to: [email protected]
Sender: [email protected]
User-agent: Mozilla/5.0 (Windows; U; Windows NT 6.1; de; rv:1.9.1.8) Gecko/20100227 Thunderbird/3.0.3
Hi all,

I would like to run some transmissions on MF WSPR but i also like to run a longer transmission on 2.97 kHz. In the current ULF TX installation i'm using a parallel 2 nF capacitor anyway. This is just -j167 Ohm on MF. I could series compensate it with 65 uH (which is just j1.2 Ohm at 2970 Hz :-) ) to ground. The 65 uH could be parallel compensated for MF, using 280 nF. Then i could add a ferrite transformer to apply the MF RF across the 65uH/280nF parallel circuit. The large loading coil of 1.3 H will be a high impedance, hopefully, as long as there is no internal resonance on MF due to its own winding capacity. The 2 nF capacitor will have to handle the sum current of ULF and MF. QRO is not possible on MF i think but it will handle a few watts which is fine for WSPR. Hmm, worth a try?
73, Stefan

<Prev in Thread] Current Thread [Next in Thread>