[600MRG] Views on Heros Longwave Converter?

[Edward R Cole]

At 05:49 PM 1/14/2013, 3up3down wrote:
>Anyone have an opinion about the Heros Technology VLF-LF receiving converter
>from England? It seems to be a more sophisticated (and costly) design than
>other converters on the market. Filtering should be much better than my
>Palomar  which works pretty well. I find no reviews of the Heros unit on the
>web.
>
>http://herostechnology.co.uk/pdf/VLF_LF_Converter_brochure_web.pdf
>
>Thanks!
>
>Jeff K0OD
>K0OD at arrl.net

Good use of filters in the unit.  Note the IF trap to isolate the LO 
from leaking into the antenna.  But there is no preamp so sensitivity 
is that of the balanced mixer.  Also LO is rated for +/- 10ppm at 
either 3.5 MHz or 4.0 MHz that translates to a frequency error of +/- 
35 or 40 Hz.

I suppose that is not so important in a receiver.  It would be 
totally unacceptable for transmitting on 472-479 KHz since one could 
find themself completely out of the band.  1ppm is still marginal.  I 
think one should look for 0.1ppm at least.

Construction looks very nice.

of course one could add a preamp.

73, Ed - KL7UW