Don't know how well it works, because I haven't put it together yet,
but these guys sell a kit for rx upconversion which I bought after
hearing it discussed here a few weeks ago:
http://wb9kzy.com/lfconv.htm
Jerry W4UK
At 02:25 PM 2/16/2012, Robert Costa, KB6QXM wrote:
As we all know that the receive of the flex is marginal at best
below 1.8 mhz. The images and birdies would make it difficult at
best to use the flex down there. Flex Radio does not even supply
sensitivity specifications for the receiver at those frequencies. As
I have an intense desire to use the Flex at VLF and LF, I have been
researching band pass filters and would love to see someone design a
variable preselector for Vlf/Lf that can make the Flex a respectful
receiver at those frequencies. My only thought is to use a
transverter that outputs at 4 mhz.
I would like to hear how you geared up as I would love to experiment
with my flex on the lowfer(160-190 khz) band.
73,
Robert
KB6QXM
"Ham Radio Open Conversation"
Yahoo group owner/moderator
----- Reply message -----
From: "Lloyd Berg N9LB" <lloydb...@charter.net>
To: <flexradio@flex-radio.biz>
Subject: [Flexradio] The new 472-479 kHz band - Technical Info
Date: Thu, Feb 16, 2012 10:32 am
All,
While the 1 watt to 5 watt power seems small, it really isn't because
the specification is Effective Radiated Power. An efficient dipole
antenna at this frequency would be about 1000 feet long, a 1/4 wave
vertical would be over 500 feet tall.
If you are running a 60 foot vertical ( requiring a huge matching
network ), your efficiency would only be a few percent, therefore your
transmitter power output would be somewhere around 100 watts.
That is still very low communications power, but quite suitable for CW
and some digital modes over 100's of miles - maybe more.
I plan to gear up for it and be ready to go on the first day operation
becomes legal. Yes I'll be using my FLEX-5000. Transmitting will
probably require some form of low frequency transverter. Receiving
might just require filtering and possibly a pre-amp.
I'm looking forward to exploring a whole new band!
73
Lloyd - N9LB
Message: 3
Date: Wed, 15 Feb 2012 12:55:14 -0800
From: " Robert Costa, KB6QXM " <kb6...@yahoo.com>
To: " Stephen Victor " <victo...@yahoo.com>, "
flexradio@flex-radio.biz " <flexradio@flex-radio.biz>
Subject: Re: [Flexradio] The new 472-479 kHz band
Message-ID: <648839.89845...@smtp217.mail.gq1.yahoo.com>
Content-Type: text/plain; charset=utf-8
1 watt maximum EIRP. Big deal.
Not too exciting news. I am glad to hear that we have some Medium
Frequency spectrum, but 1 watt output and the size of the antenna is
almost not worth the effort. The requirements remind me of the lowfer
band (160-190 khz) limitations.
This is almost part 15 output.
How about giving back the lower portion of the 220 band.
73,
Robert
KB6QXM
"Ham Radio Open Conversation"
Yahoo group owner/moderator
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