The original cable was Belden 8421 Low Capacitance microphone shielded
wire. It was the same size and flexibility of the other 'audio' cables,
and about one-half the capacitance. RG-62 will work, but is MUCH
thicker, stiffer and damage prone if bent over too tight a radius. It's
also somewhat difficult to solder without melting the almost
non-existent dielectric. That said, it IS cheap, as many miles of it
was pulled out of attics (and many miles still remain!) as relics of
earlier computer networking systems.
The original cable, 38" long tip-to-tip, had a total capacitance of 60
pF. RG-59A/U will also work, but is about the same size as RG-62,
although it is considerably more flexible. A list member bought a
quantity of 8421 a while back, and may still have some. I think it's
still available by the foot from ACK in Atlanta, but everyone else wants
to sell you a 500' spool!
Also use good quality connectors, I prefer Switchcraft 3502. They have
a nice backshell that encourages you to pull on that rather than just
yank on the cable! :-)
Regardless of what cable you use, it's best to tweak up the INJ trimmers
on the receiver and transmitter with the two units cabled together.
This will provide the highest levels of received and transmitted signal
when in transceive mode. There is almost always a slight reduction in
the 'non-controlling' unit, but should be very little.
73, Garey - K4OAH
Glen Allen, VA
Drake 2-B, 2-C/2-NT, 4-B, C-Line&
TR-4/C Service Supplement CDs
<www.k4oah.com>
Eugene Balinski wrote:
The injection cable is nominally RG-62. It is available
from a number of sources if want to make your own cable
for the Drakes
73, Gene
K1NR
On Sat, 04 Dec 2010 20:19:34 -0500
Garey Barrell<k4...@mindspring.com> wrote:
Joe -
When all else fails.... :-)
Yes, the INJ cable provided by Drake was a special, low
capacity cable, cleverly marked for 'INJ'. It will
definitely increase the transmitter output when
transceiving under RCVR control. Works the other way
too, received signals are louder when using XMTR control
as well.
I believe your 'double PTO' problem was just corrosion on
the 'non-INJ' cable's pins.
All's well that .....
73, Garey - K4OAH
Glen Allen, VA
Drake 2-B, 2-C/2-NT, 4-B, C-Line&
TR-4/C Service Supplement CDs
<www.k4oah.com>
Joe Loverti wrote:
Gary,
I found the original drake injection cable... it has a
metal tag
crimped to it that reads: INJ. When I use that cable my
RF output on
the T-4XB increases nearly 30 watts! It feels like I
installed a new
set of finals. And the problem of the PTOs has
disappeared. Nothing
like original equipment!
Thanks!
73,
WW8X
Joe Loverti Sr.
Miamisburg, Ohiio
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