Very Low Frequency Up Converter
 

I have searched the web looking for a good VLF up converter and came to the
following conclusions:

1. The Palomar converter is not a good choice.
2. There was a converter article that was published by "Burhans
Electronics" but I cannot find any info on it.
3. There is a design by KF5CQ but cannot find anyone that has built one and
commented on it.
4. There is a company called North County Radio that sells a kit called
LFCON and again cannot find anyone that has built this and commented on it.
5. I saw a product from LF Engineering that uses a SBL-1 mixer, where the
KF5CQ design uses a SBL-3 mixer

Does anyone on the group have any experience with the LFCON?

I would also appreciate any info on experiences with the above mentioned VLF
up converters or any other up converters.

Thanks

Jim

see http://home.att.net/~jacksonharbor/lfconv.htm Jackson Harbor Press
kit - $12 for the basic kit (10 to 300 khz to HF) with the crystal
included, parts and circuit board etc. They take paypal etc.

hope this helps bobm
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************************************************** *********************
* Robert Monaghan POB 752182 Southern Methodist Univ. Dallas Tx 75275 *
********************Standard Disclaimers Apply*************************

Bob,

Thanks for the info.

Do you have any experience with this kit?

One question I have is the since the converter has a simple local
oscillator, will the "readout" be accurate and will the frequency be
"stable"??

Thanks

Jim


Bob Monaghan wrote in message
...

see http://home.att.net/~jacksonharbor/lfconv.htm Jackson Harbor Press
kit - $12 for the basic kit (10 to 300 khz to HF) with the crystal
included, parts and circuit board etc. They take paypal etc.

hope this helps bobm
--
************************************************** *********************
* Robert Monaghan POB 752182 Southern Methodist Univ. Dallas Tx 75275 *
********************Standard Disclaimers Apply*************************

"Jim" ) writes:
Bob,

Thanks for the info.

Do you have any experience with this kit?

One question I have is the since the converter has a simple local
oscillator, will the "readout" be accurate and will the frequency be
"stable"??

Thanks

Jim


A crystal controlled converter is a very old scheme to add coverage
to an existing receiver. Since it's crystal controlled, there would
have to be very odd circumstances for it to be unstable.

All you do is add the frequency of the crystal to the frequency
displayed on the receiver. It's easy so long as the crystal in
the converter is a nice even frequency. In the analog days, the calibration
of the dial would likely be more significant than the exact frequency
of the crystal. With digital redout receivers, this is likely somewhat of
an issue, since while the crystal will stay on frequency, in the circuit
it may oscillate at a slightly difference frequency from the marking on
the case. If you're lucky, the converter has a trimmer capacitor for
this sort of adjustment; all you'd have to do is tune in the oscillator
frequency with your receiver and see if it's on frequency. If not, then
you adjsut the trimmer. If there's no trimmer, you still take note of
the crystal frequency in the receiver, and use that knowledge to adjust
your mental readout. If it's 1KHz off from the marked frequency, then you
know you know you will have to add or subtract that amount (depending on the
direction of the offset) when looking at the receiver's readout.

Michael
Bob Monaghan wrote in message
...
see http://home.att.net/~jacksonharbor/lfconv.htm Jackson Harbor Press
kit - $12 for the basic kit (10 to 300 khz to HF) with the crystal
included, parts and circuit board etc. They take paypal etc.

hope this helps bobm
--
************************************************** *********************
* Robert Monaghan POB 752182 Southern Methodist Univ. Dallas Tx 75275 *
********************Standard Disclaimers Apply*************************

there is not a trimmer capacitor in the crystal circuit IIRC, though you
could probably add one if needed. You have (or I had) a choice of 3
crystals and bands, and I picked the 10.000 Mhz crystal since I could
check it against WWV and it would be a handy item for use as a frequency
reference if I ever junked the kit ;-)

You will want a well shielded housing if you live in an urban area with
powerful transmitters (AM..) nearby. In bad cases, an outboard low pass
filter might be needed (see ARRL handbook for circuits etc.).

Many of the digital dials on moderate cost digital receivers are not zero
beat-able against WWV, and BFO settings etc. may interact as well,
so an approximate readout is all most of us will get anyway ;-)

hth bobm
--
************************************************** *********************
* Robert Monaghan POB 752182 Southern Methodist Univ. Dallas Tx 75275 *
********************Standard Disclaimers Apply*************************