[Hallicrafters] More on digital display for SX-71

[Philip Atchley]

Hello all,
I provided Neil with all the LO info on the SX-71.  It looks like a version
of the DFD1 will be coming down the pike, here's his reply and other
correspondence below my signature.

73 from the "Beaconeers Lair".
Phil, KO6BB

<Neil>

I have been working on a DFD1-National, similar to the DFD1-Hammarlund,
which includes the NC-183D.
I will add the SX-71 to that unit then we can test it somehow.
Sales a slow in April, probably because of income tax shock, so I will have
time to work on that some today.

Hi Neil,
Thank you for your help.  This evening I used a digital portable and checked
the LO frequencies for each band except for Band 5 (47-55MHz) as I didn't
have anything that could "hear" that one.  See the chart below.

Band    Freq spread of Band           Actual LO spread       LO offset
1          560 - 1600 KC                  1015 - 2055 KC        + 455 KC
2          1700 - 4500 KC                 2155 - 4955 KC       + 455 KC
3          4800 - 13,000 KC              6875 - 15,075 KC     +2075 KC
4          13,000 - 34,000 KC           15,075 - 36,075 KC  +2075 KC
5           47,000 - 55,000 KC          Unknown                    Don't
know if LO is above or below the frequency.

73 from the "Beaconeers Lair".
Phil, KO6BB

> I looked at the manual copy I have and it has absolutely nothing about how
> the radio works or the LO frequencies.
> Without details of LO frequencies for each band I cannot develop the unit.
>
>
> > This works similar to the hammarlunds and I could add this radio to the
> > DFD1-hammarlund software.
> > Otherwise you can use DFD3 and manually program it for the SX-71
> >