drake CW TX sidebands? (newbie ?)
 

I just aquired a Drake TR4c.

It's my first "boatanchor" rig... and am still getting use to it.

Question;

In CW, the the Sideband switch must be on the "X" side to TX.... But as
I cycle thru the bands, some (80,15,10m)are on the wrong sideband (as
shown by the indicator light).

Is this a problem? The manual says the freq is shifted during CW TX but
does the Drake TX on the normal ( upper above 40m ) sidebands
Or does it shift to the sideband as indicated on by the light??
Which would make it wrong on the above listed bands.

thanks in advance
Tom aa2vk

drake CW TX sidebands? (newbie ?)
 

In CW, the the Sideband switch must be on the "X" side to TX.... But as
I cycle thru the bands, some (80,15,10m)are on the wrong sideband (as
shown by the indicator light).

The sideband concept is only meaningful for SSB. Convention is to use LSB on 80 and 40, and USB on 20, 15 and 10.

On CW you transmit just a plain carrier that has no sidebands. Therefore noone can determine which filter you use when transmitting CW. In principle you could use either of the two filters without fear of infringing any convention. But the TR-4 requires that, on CW, you always use the same filter (that marked X). That filter, on SSB, is for the upper sideband on certain bands or for lower sideband on other bands. But this matters only when you work SSB. For CW you put the switch to X and forget.

Tony I0JX

drake CW TX sidebands? (newbie ?)
 

Hi

Your question on the Drake TR-4 in c.w. mode,
you should always keep the switch in the "x" sideband
position for c.w. In the "x" position, during c.w. or a.m. transmit,
the 9mc BFO crystal frequency will be shifted into the passband
of the "x" SSB filter, to reduce carrier loss through the filter.

On some bands, in c.w. mode, you will be listening on USB,
and other bands you will be listening on LSB,
as indicated by the red indicator lights. Thus, you talk about
the "x" filter instead of USB or LSB filter, because
the "x" filter will be for USB on some bands and LSB
on other bands.

The "upper" or "lower" light varies with the band switch
for the same reason that the frequency dial calibrations
read +lower+ on some bands
when you advance the dial clockwise.

The reason for this behavior is that Drake used either a sum
of two frequencies or a difference of two frequencies
to generate a third frequency, depending on the band.

The sideband filters are near 9mc,
the VFO runs between 4.9 and 5.5mc.

This was done for economy:
The sum and the difference will put you on 80m or 20m
without any other mixers needed.
(single conversion design on 80 and 20m).

73,
Ed Knobloch


TJM wrote:
I just aquired a Drake TR4c.

It's my first "boatanchor" rig... and am still getting use to it.

Question;

In CW, the the Sideband switch must be on the "X" side to TX.... But as
I cycle thru the bands, some (80,15,10m)are on the wrong sideband (as
shown by the indicator light).

Is this a problem? The manual says the freq is shifted during CW TX but
does the Drake TX on the normal ( upper above 40m ) sidebands
Or does it shift to the sideband as indicated on by the light??
Which would make it wrong on the above listed bands.

thanks in advance
Tom aa2vk