DX-60 QUESTIONS

[Sandy W5TVW]

At 01:01 PM 7/25/98 -0400, you wrote:
>Hi, I just bought 2 dx-60's......Has anybody replaced the caps in your rig?
>I mean the big 40Ufd 450 volt ones.  can I substitue the 40 Ufd ones for
>47ufd?  I am not sure the 40 ufd ones are still available.  Would switching
>caps make a big difference, or are the values close enough?
>    There is another cap  its a 2X20ufd.  it has one lead going in and 2
>coming out.  I guess it is just 2 self contained caps in parallel.  does
>anyone know of a replacement .

        The 40 Mf @ 450 volt caps are NOT critical, value wise.  You can use
anything from 30-100 Mf. @ 450 volts.  They can be individual pigtail types,
"Snap-in" types...whatever you can get in the rig in the provided space.
Generally, on filter capacitors it is better to err on a larger value rather
than a small value in Microfarads, as long as the working voltage is 450.
        On the dual 20 Mf. @ 200 volts cap, you can use two seperate 20 or 25 or
30 Mf capacitors @ 200 or 250 volt rating.


>    other questions....One of the models is the dx-60, and the other is the
>dx-60a.  The dx-60 has a 1/4" jack for the microphone, and the 60A has like
>a screw on type mic, ???? can the jack just be replaced with a 1/4" jack.
>any mods i dont know about that.

        The DX-60 series all used the single contact Amphenol 75PC-1M (screw-on)
connector.  This was pretty standard on all rigs at the time not using
push-to-talk
microphones.  The 1/4" phone jack is someone's modification!

>I got the 60A in the mail yesterday, and went thru it and it looked good so
>tried it out and no smoke....but the rig puts out a carrier upon selection
>of AM, OR CW.  I thought it would only key up if the key was held down, or
>the microphone was engaged.  any ideas?

        The rig will transmit in the AM or CW position with no key inserted!
The
key jack shorts when the key is unplugged.  This is normal.  The rig should be
loaded up to 150 ma. plate current with 2-3 ma. of grid drive on CW.  When
you switch to AM the plate current will drop to a low value and the rig will
deliver 10 watts or so.  When you talk into the nicrophone and fully
modulate the rig, the
plate current will peak around 150 ma or so.

>    ok, only one more question....next to the 6146 in the final section,
>there is a separate wire thats just loose..  it comes up thru the bottom of
>the rig tray...what is it for.?
>  seems like it performs nothing.

        This is the "neutralizing stub" or capacitor actually.  It should be
positioned around 1/4" from the 6146 envelope.  There is detailed
instructions in the manual
on how to neutralize the final stage.  This procedure is normally done on
the 10 meter band.  Usually just positioning the stub 1/4" from the tube
does the job.
The idea is that the final stage shouldn't oscillate on its own.
"Neutralization"
is the process whereby it's adjusted to prevent this happening.73,

        Hope this helps.
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>
E. V. Sandy Blaize, W5TVW
"Boat Anchors collected, restored, repaired, traded and used!"
417 Ridgewood Drive
Metairie, LA., 70001

***Looking for a Hallicrafters SR-400, SR-75, SR-34******
*** TRC-10 transceiver, and an RAL receiver ******

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