[amsat-bb] Re: 23cm TX converters with 435 MHz IF

[Yoshihiro Imaishi <imaishi@xxxxxxxxxxxx>]

Hello This is Yoshi.

At 2002/04/02 13:49:58 Wayne Estes W9AE wrote:
> I'm looking for commercially made (or kit) 23cm TX converters that use a 435
> MHz IF.  The only one I can find is the Kuhne MKU13OTX with the 70IF option
> which is described in the SSBUSA web site, but isn't included in the SSBUSA
> price list.  Are there others?

  I think that the design of ALL-Mode Transverter (NOT only for FM)
from 70cm to 23cm has a problem of image signal. In the Japanese
market, there is no 1.2GHz transverter model like that (except a
model of MAKI DENKI but no stock already).
  1295MHz -> 435MHz conversion reqires 860MHz LO, but that frequency
is too close to the double of original signal 435MHz (870MHz). Maybe
this mixing products many images at around 435MHz/1295MHz and it is
difficult to cut out by normal filter. I think this is the main
reason that most manufactures do not make models for 23cm-70cm
transvert.

  But, in the case of up-conversion for AO-40, 435MHz -> 1268MHz
requires 833MHz LO and this is not so much close to the doube of
435MHz (870MHz), and it will possible to cut images out by normal
filter. MKU13OTX might stand on this theory I think.


Yoshihiro Imaishi JF6BCC/KH2GR
GL:PM53JV, ex KC6IY(T88IY),V63BP
mailto:jf6bcc@jarl.com
<http://plaza16.mbn.or.jp/~palau/index-hame.html>

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