[AMRadio] DX 100 question

Sat Apr 23 16:57:13 EDT 2011

Hi Jim,

On My DX-100 I have trouble getting enough drive on 10 meters also. I think
that it only provides 4 ma grid current if I remember.
The Apache drive control has to be cranked up all the way to make 5 ma of
grid current on 10. There is way more than enough drive on the lower bands.

There was a modification for adding a neutralization stub latter on. Mine
has it in there and you get less grid current with it. Without the stub
there is more feed back and that gives an apparent grid current increase and
of course max power out of the final is not at minimum plate current and
grid current does not peak at max power out either.
But when the neutralization is close grid drive is marginal. At least on
mine.

The second tap on the coils does seem strange though.

73
Gary  K4FMX

> -----Original Message-----
> From: amradio-bounces at mailman.qth.net [mailto:amradio-
> bounces at mailman.qth.net] On Behalf Of Jim Wilhite
> Sent: Saturday, April 23, 2011 4:41 PM
> To: Discussion of AM Radio in the Amateur Service
> Subject: Re: [AMRadio] DX 100 question
> 
> Thank you Gary and Craig,
> 
> Yes this has 11 meters on it but no separate tap for that band.  It uses
> the 10 meter coil and the tuning cap is varied a bit is all.  With that
> information I can rewind this one .  It is also 17 turns but tapped at 8
> 1/2 and 12 1/2 turns from the bandswitch.  That 2nd tap only leaves 5
> turns on the coil, not enough for 10.
> 
> I have good grid drive on all band but 10 and I can fix the problem, I
> could make this work, but want it like the book so the next person will
> know what is going on.  Another odd thing is some one in this
> transmitter's previous life added a wafer behind the driver bandswitch.
> It was a break then make 7 position switch and they had moved the final
> coils tap points to it rather than the ceramic shorting switch designed
> for it.
> 
> Strange stuff can be found it Heath equipment.
> 
> 
> ----- Original Message -----
> From: "Gary Schafer" <garyschafer at comcast.net>
> To: "'Discussion of AM Radio in the Amateur Service'"
> <amradio at mailman.qth.net>
> Sent: Saturday, April 23, 2011 3:09 PM
> Subject: Re: [AMRadio] DX 100 question
> 
> 
> > Hi Jim,
> >
> > The total turns on that coil are 17. it has the tap at 9 1/2 turns
> > from the
> > grid end. That leaves 8 turns on the 15 meter part of the coil.
> > The 10 meter part is wound tightly with the turns touching each other.
> > On
> > the 15 meter part the turns are spaced at around 1/8 inch between
> > turns.
> > Actually the last turn on 10 meters near the tap is spaced out about
> > 1/4
> > inch.
> >
> > I wonder if your DX-100 is an early model with 11 meters on it? Did
> > they
> > have a separate tap for 11 meters?
> >
> > 73
> > Gary  K4FMX
> >
> >> -----Original Message-----
> >> From: amradio-bounces at mailman.qth.net [mailto:amradio-
> >> bounces at mailman.qth.net] On Behalf Of Jim Wilhite
> >> Sent: Saturday, April 23, 2011 3:32 PM
> >> To: Discussion of AM Radio in the Amateur Service
> >> Subject: Re: [AMRadio] DX 100 question
> >>
> >> Thanks for looking Gary,
> >>
> >> Yes that is the plate coil of the driver, one end to the final grids
> >> and
> >> the other tied to two point on the bandswitch.  What has me going is
> >> the
> >> one in this DX 100 is 3/4" in diameter (same as yours) and has two
> >> taps
> >> rather than the one you have.  I didn't, and still don't, know were
> >> this
> >> coil came from.  I though the Apache used the two tap coil for 10 and
> >> 15
> >> + part of 20, which the DX 100 didn't.
> >>
> >> Evidently I was wrong.  If you still have the transmitter where you
> >> can
> >> see, how many turns on the total coil?    I sure appreciate your
> >> help.
> >>
> >> 73
> >>
> >> Jim/W5JO
> >>
> >>
> >>
> >>
> >> ----- Original Message -----
> >>
> >>
> >> > Hi Jim,
> >> >
> >> > I have my Apache turned on its side right now so I can see the
> >> > coils
> >> > underneath. My DX100 is in the cabinet and buried under a bunch of
> >> > stuff.
> >> >
> >> > The coil in the Apache has only 1 tap in the center. This is the
> >> > small
> >> > air
> >> > wound coil about 3/4 inch in diameter. Part of it is spread out.
> >> >
> >> > Is this the coil you are looking at?
> >> >
> >> > 73
> >> > Gary  K4FMX
> >> >
> >> >> -----Original Message-----
> >> >> From: amradio-bounces at mailman.qth.net [mailto:amradio-
> >> >> bounces at mailman.qth.net] On Behalf Of Jim Wilhite
> >> >> Sent: Saturday, April 23, 2011 11:54 AM
> >> >> To: AM Radio Discussion List
> >> >> Subject: [AMRadio] DX 100 question
> >> >>
> >> >> Hi all,
> >> >>
> >> >> I have a DX 100 that has the wrong coil in the driver plate
> >> >> circuit
> >> >> or
> >> >> at least it seems.  The one in it has two taps, which I believe
> >> >> is
> >> >> for
> >> >> an Apache, but I am not really sure.  The DX 100 version is
> >> >> supposed
> >> >> to
> >> >> have just one tap about midpoint.  The taps on this one is not as
> >> >> specified for the DX 100.
> >> >>
> >> >> What I would like to know is how many turns the coil for the DX
> >> >> 100
> >> >> has.
> >> >> I can redo this one if I know how many turns to wind.  Thanks for
> >> >> any
> >> >> help.
> >> >>
> >> >> Jim/W5JO
> >> >>
> >> >> ______________________________________________________________
> >> >> Our Main Website: http://www.amfone.net
> >> >> AMRadio mailing list
> >> >> Searchable Archives: http://www.mail-
> >> >> archive.com/amradio at mailman.qth.net/
> >> >> List Rules (must read!): http://w5ami.net/amradiofaq.html
> >> >> List Home: http://mailman.qth.net/mailman/listinfo/amradio
> >> >> Post: AMRadio at mailman.qth.net
> >> >> To unsubscribe, send an email to amradio-request at mailman.qth.net
> >> >> with
> >> >> the word unsubscribe in the message body.
> >> >>
> >> >> This list hosted by: http://www.qsl.net
> >> >> Please help support this email list:
> >> >> http://www.qsl.net/donate.html
> >> >
> >> > ______________________________________________________________
> >> > Our Main Website: http://www.amfone.net
> >> > AMRadio mailing list
> >> > Searchable Archives:
> >> > http://www.mail-archive.com/[email protected]/
> >> > List Rules (must read!): http://w5ami.net/amradiofaq.html
> >> > List Home: http://mailman.qth.net/mailman/listinfo/amradio
> >> > Post: AMRadio at mailman.qth.net
> >> > To unsubscribe, send an email to amradio-request at mailman.qth.net
> >> > with
> >> > the word unsubscribe in the message body.
> >> >
> >> > This list hosted by: http://www.qsl.net
> >> > Please help support this email list: http://www.qsl.net/donate.html
> >> >
> >>
> >> ______________________________________________________________
> >> Our Main Website: http://www.amfone.net
> >> AMRadio mailing list
> >> Searchable Archives: http://www.mail-
> >> archive.com/amradio at mailman.qth.net/
> >> List Rules (must read!): http://w5ami.net/amradiofaq.html
> >> List Home: http://mailman.qth.net/mailman/listinfo/amradio
> >> Post: AMRadio at mailman.qth.net
> >> To unsubscribe, send an email to amradio-request at mailman.qth.net with
> >> the word unsubscribe in the message body.
> >>
> >> This list hosted by: http://www.qsl.net
> >> Please help support this email list: http://www.qsl.net/donate.html
> >
> > ______________________________________________________________
> > Our Main Website: http://www.amfone.net
> > AMRadio mailing list
> > Searchable Archives:
> > http://www.mail-archive.com/[email protected]/
> > List Rules (must read!): http://w5ami.net/amradiofaq.html
> > List Home: http://mailman.qth.net/mailman/listinfo/amradio
> > Post: AMRadio at mailman.qth.net
> > To unsubscribe, send an email to amradio-request at mailman.qth.net with
> > the word unsubscribe in the message body.
> >
> > This list hosted by: http://www.qsl.net
> > Please help support this email list: http://www.qsl.net/donate.html
> >
> 
> ______________________________________________________________
> Our Main Website: http://www.amfone.net
> AMRadio mailing list
> Searchable Archives: http://www.mail-
> archive.com/amradio at mailman.qth.net/
> List Rules (must read!): http://w5ami.net/amradiofaq.html
> List Home: http://mailman.qth.net/mailman/listinfo/amradio
> Post: AMRadio at mailman.qth.net
> To unsubscribe, send an email to amradio-request at mailman.qth.net with
> the word unsubscribe in the message body.
> 
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html