Re: LF: Re: Mini-Whip Antenna

["Ken" <ken.h.wright@btinternet.com>]

Hello Roelof.
Very interesting, I am just about to commission my MiniWhip, the hold up has 
been several things, firstly winding a high value power take-off inductor, 
but mainly what to seal the ends of the plastic pipe with to make it really 
water tight. I assume that you terminate the coax directly onto the pcb, no 
connectors. How do your experimental J310 bias values compare with the 
original circuit component values?.This MiniWhip is certainly attracting a 
lot of attention, at least it will keep the J310 manufacturers busy.
73s and best regards
 Ken
M0KHW


----- Original Message ----- 
From: "Roelof Bakker" <roelof@ndb.demon.nl>
To: <rsgb_lf_group@blacksheep.org>
Sent: Tuesday, January 18, 2011 8:20 PM
Subject: Re: LF: Re: Mini-Whip Antenna


> Hello Minto,
>
> In laboratory tests it is possible to tweak the bias of the J310 for a 
> very high IP2 of +80 dBm and a IP3 of +33 dBm.
> However this does not hold in off air tests.
>
> I use the medium wave stations at Orford Ness, UK as off air signal 
> generators.
> The station at 648 kHz is on 24/7, but the one at 1296 kHz only in part of 
> the morning and between 16:00 and 17:00 UTC.
> I found IP3's ranging from about + 15dBm to + 20 dBm depending on supply 
> voltage.
> Maybe you can use these stations as well for test purposes.
> At my location they produce each -20 dBm at the output of a mini-whip 
> mounted 5 metre up.
> Except for the directive properties of a loop, both loops and whips can 
> deliver stellar performance on reception.
> It depends on the local noise situation which type of antenna gives best 
> results.
> 73,
> Roelof, pa0rdt