On Thu, 24 Jul 2014 00:50:28 -0400, Michael Black
wrote:

On Thu, 24 Jul 2014, Barry OGrady wrote:

I recently obtained a Yaesu FTDX-400. I have operation and
service manuals but I can't find how to add bands.

Well there are no diodes to clip on that baby, if that's what
you're asking.

You'll have to take out the bandswitch, put in a new one with more
positions, then add any needed coils and crystals for the new bands.

You probably thought it was a silly question but the FTDX-400
comes standard with the ability to add three 500Khz bands.

This rig dates from 1967. The bands had been more or less stable for some
time (well 11 metres was lost in the US and mostly lost in Canada in the
late fifties). That only changed in 1979 when the original WARC bands
were added. Some rigs did have auxiliary band positions, so you could
accomdate a new band. But for the most part, the old rigs stayed on the
old bands, while new rigs came along (now 35 years old) that could
accomodate the new bands. My TS-830 covers the WARC bands, it came out
just at the right time. But something a bit earlier likely lacked the
capability.

I do believe some WARC bands can be added to the FTDX-400 or could
be CB and so called freeband.

Then shortly after the WARC bands came into use, the rigs started
changing, no crystal for each band, it was all synthesized so the
potential for broader tuning was there. That's where the "clip
the diode" notion comes from, later rigs that could tune wider, but
had restricted tuning as they came from the factory. After a bit,
every new rig had a general coverage receiver, any control over
frequency coverage was about transmitting.

I was able to expand transmit and receive of my Yaesu FT-50 without
opening the case.

So I know my boatanchor can have three bands added but still don't
know how.

Michael

--
There is something outrageous about such a huge body of evidence being
put together, then being confirmed in all kinds of other scientific
disciplines, particularly genetics, and having other people just sort
of deny it for reasons that have nothing to do with truth.
– Matthew Chapman, Darwin's great-great-grandson.