[Premium-Rx] 3030 keypads, etc

refmon monitor at referencevideo.com
Tue Jul 1 21:47:23 EDT 2003 

Hi,

Points well made and I even learned a concept or two, however, I'm not sure
this line of exploration applies to the Cubic radios, or others, either.
The situation on these receivers is quite different than the software
scenario described.  Entries (keypushes) are made in a comparatively
deliberate, slow manner.  I expect that under original specs, the front
panel controls were mainly considered maintenance controls, as these
receivers typically were used in remoted banks under tasking software.
While mid 80's technology would allow sophisticated debounce and other such
considerations, I expect it was deliberately decided not to bother.  The
Cubic keypad is column/row matrixed and a 74C923 keyboard encode/decode IC
with internal debounce is used...pin 7 provides for a user-selected damping
cap.  Relatively crude but effective.  Actually, if I didn't have a
3030A...just 3030's, which don't bounce, I'd never have paid any attention
to this aspect of the receiver;  once you have the feel, the existing system
works just fine.  Worthy of note is the fact that some, if not most, of us
want to keep the receivers as true to original as is consistent with our
usage.

Particularly interesting to me is the fact that inquiries to the Cubic
factory get a "bad keypad" diagnosis...Cubic does not have any spares, so
doubtful that's a sales-driven thing....more likely a nice guy trying to
help, but no docs in hand.  Also interesting is the docs indicate that rev B
incorporated the adjusted cap value of 10uf, but we're finding rev B boards
with the old cap values of 3.3uf.  Further, these keypads have buttons of
the "oil can" variety, which are prone to be bouncy...a plain old button
pushes in when you push it and opens when you release....these buttons, on a
vary small scale, fight your push...I found that the more respect I showed
for the vintage keypads, the more they bounce.  Until the cap thing was
discovered, a Cubic operator developed a debounced pushing finger...fast and
crisp...sneaks in under the 3.3uf time constant.

It is always worth remembering that for most of these premium rx's, we are
using them well outside their originally intended applications.  I seriously
doubt that these receivers were ever envisioned plugged into a wall outlet
in someone's house, nor were they designed to have someone listen to them
endlessly while trying to dig out minimum discernable signals.  These
receivers are intended to be in computer-controlled banks receiving highly
processed RF from large scale antenna systems.  Enclosures and facilities
are shielded, power is processed.

Anyway, problem solved...on to the next one.

regards

John Collins
______________________________________________________
----- Original Message ----- 
From: "John Perlick" <p at mn.rr.com>
To: "Henry Kolesnik" <wd5jfr at oklahoma.net>; "refmon"
<monitor at referencevideo.com>
Cc: <premium-rx at ml.skirrow.org>
Sent: Tuesday, July 01, 2003 04:03 PM
Subject: Re: [Premium-Rx] 3030 keypads


> Gary G brought up some good points, for Form-C switches, and yes, you can
> make an excellent hardware debounce with SPDT switches.  And, he is right,
> no one ever makes SPDT switches in keypads or keyboards.  So you are left
> with software debounce.
>
> When I say software, I guess this really would be firmware.  In any
> keyboard, there is a microprocessor (or microcontroller) which reads the
> matrix keyboard switches (typically an 8051 or Z-80 or something related).
> The uP also serializes the data and sends it to the computer.  All the
> computer knows is that a "C' key was pressed once.  The micro usually
> fulfills the repeat function in the keyboard.
>
> In the case of keypads, which are often matrixed also (if matrixed is a
> word), then this debounce "software" function is also usually done in the
> local micro.   This is not something that  you see running in DOS
software.
>
> The software debounce typically does a couple of things (that are
> accomplished MUCH more easily in software than in hardware):  First, it
will
> see a key closure.  It will watch to see that the key stays closed for a
> certain amount of time (not bouncing).  THis is a noise filter--assuming
> that you might have had a noise pulse look like a key closure, but
typically
> not a few consecutive reads.  If they key is closed for 3-5 consecutive
> reads, then you assume you have a valid key hit.  Then you start a second
> read sequence to see that the key is opened within a certain time.  If
not,
> then you assume you want multiple characters.  And, finally, when you
> finally do read an open on the key read, you assume that the key is open
and
> you ignore any possible closure for a short interval (this is the actual
> debounce).  So, keypad/keyboard debouncing is not trivial, and best done
in
> firmware.  Yes, software can lock up or screw up (my keyboard does once a
> year or so) so you have to deal with that.  On the other hand, it is much
> more immune to noise this way.  Fast is really not the point...even with a
4
> MHz clock (typical for most keyboards) you can do all of this debouncing
> MUCH faster than anyones  fingers can move!  So, fast hardware gets you
> nothing because all you are doing is slowing down fast hardware for noise
> immunity.  I do like the last comment....I'd love to bounce...just not on
my
> keyboard.
>
> John
> K0UM
> ----- Original Message -----
> From: "Henry Kolesnik" <wd5jfr at oklahoma.net>
> To: "John Perlick" <p at mn.rr.com>; "refmon" <monitor at referencevideo.com>
> Cc: <premium-rx at ml.skirrow.org>
> Sent: Tuesday, July 01, 2003 4:02 PM
> Subject: Re: [Premium-Rx] 3030 keypads
>
>
> > I may be a off on this but I would think a hardware debounce would be
much
> > more effective than software debounce because:
> > 1. it's a hardware feature that's not wanted or a malfunction..
> > 2. hardware would be faster!
> > 3. firmware would be the second choice..
> > 4. don't waste software doing something that easily done in hardware
> unless
> > you've got the resources and may need bounce later..
> > 5. when would anyone want bounce or the ability to control it in
software?
> >
> > tnx
> > 73
> > hank wd5jfr
> > ----- Original Message -----
> > From: "John Perlick" <p at mn.rr.com>
> > To: "Henry Kolesnik" <wd5jfr at oklahoma.net>; "refmon"
> > <monitor at referencevideo.com>
> > Cc: <premium-rx at ml.skirrow.org>
> > Sent: Monday, June 30, 2003 2:22 PM
> > Subject: Re: [Premium-Rx] 3030 keypads
> >
> >
> > > Keypad debouncing is best done in software...
> > > ----- Original Message -----
> > > From: "Henry Kolesnik" <wd5jfr at oklahoma.net>
> > > To: "refmon" <monitor at referencevideo.com>
> > > Cc: <premium-rx at ml.skirrow.org>
> > > Sent: Monday, June 30, 2003 12:36 PM
> > > Subject: Re: [Premium-Rx] 3030 keypads
> > >
> > >
> > > > John
> > > > That sounds like a great idea.  I've done a bit of snooping and if I
> > read
> > > it
> > > > right Cubic uses Grayhill 88JB2 which is available from Digi-Key for
> > > $27.74.
> > > > I wonder if anyone can confirm this number as I would like to have
> > > > bounceless keypads on my A model.
> > > > 73
> > > > hank wd5jfr
> > > > ----- Original Message -----
> > > > From: "refmon" <monitor at referencevideo.com>
> > > > To: "Carcia, Frank A. HS" <francis.carcia at hs.utc.com>; "'Herschel
> > > > McCullough'" <w5mc at austin.rr.com>; "Al Klase"
<skywaves at bw.webex.net>
> > > > Cc: <premium-rx at ml.skirrow.org>
> > > > Sent: Monday, June 30, 2003 12:30 PM
> > > > Subject: Re: [Premium-Rx] 3030 keypads
> > > >
> > > >
> > > > > Hi Frank et al,
> > > > >
> > > > > As far as I can determine, all the keypad switch assy's are the
> > > > same...it's
> > > > > the overlay and firmware that varies by model & options.  I know
you
> > > have
> > > > a
> > > > > few other models...I can't speak for them, but do any of the keys
on
> > > 3512,
> > > > > etc bounce?
> > > > >
> > > > > I still find it highly suspect that all 3030A's so far have baggy
> > > overlays
> > > > > and bouncy switches....all 3030's have firm overlays and no
bounce.
> > > > Before
> > > > > everyone runs out and buys new switches, let's figure out if all
the
> > > > 3030A's
> > > > > have bad keypads or if they're simply not debounced.  As a start,
I
> > will
> > > > > pour through my manuals .. failing an answer there, I'll check
panel
> > > > > interfaces between 3030A and 3030, including PC board # and rev.
If
> > > > > everything there is the same, I'll swap a known-good keypad, which
> is
> > a
> > > > ton
> > > > > of work, and see if that makes a difference.
> > > > >
> > > > > John Collins
> > > > > ________________________________________________
> > > > > ----- Original Message -----
> > > > > From: "Carcia, Frank A. HS" <francis.carcia at hs.utc.com>
> > > > > To: "'Herschel McCullough'" <w5mc at austin.rr.com>; "Al Klase"
> > > > > <skywaves at bw.webex.net>
> > > > > Cc: <premium-rx at ml.skirrow.org>
> > > > > Sent: Monday, June 30, 2003 06:13 AM
> > > > > Subject: RE: [Premium-Rx] 3030 keypads
> > > > >
> > > > >
> > > > > > I have found a number of different key pad covers going through
> the
> > > > Cubic
> > > > > > stash. I
> > > > > > have not found a perfect match for the 3030 yet but have some
> close
> > > > ones.
> > > > > > They appear
> > > > > > to just have a backing that peals off then the pad sticks on the
> > front
> > > > of
> > > > > > the panel.
> > > > > > They appear to have no effect on bounce just a simple membrane.
I
> > will
> > > > > look
> > > > > > for switches
> > > > > > if someone can give me a part number or an idea of what they
look
> > > like.
> > > > I
> > > > > > found a number of
> > > > > > push buttons but have not looked into the configuration.      fc
> > > > > >
> > > > > >
> > > > > > -----Original Message-----
> > > > > > From: Herschel McCullough [mailto:w5mc at austin.rr.com]
> > > > > > Sent: Saturday, June 28, 2003 11:09 AM
> > > > > > To: Al Klase
> > > > > > Cc: premium-rx at ml.skirrow.org
> > > > > > Subject: Re: [Premium-Rx] 3030 keypads
> > > > > >
> > > > > >
> > > > > > Al, John, etal. as I see my 2 key pads,  the front printed
> membrane
> > > has
> > > > > > become  " de-laminated "  my words.. away somewhat from the
button
> > > > > surface,
> > > > > > and if I rub this face it will for a short time STICK back as it
> > > should,
> > > > > and
> > > > > > the button action seems good to fair in feel and proper
responses
> > > during
> > > > > > this time..  but after a short time the membrane face comes away
> and
> > > > then
> > > > > > when you actuate a key / button it typically will take 2 efforts
> to
> > > get
> > > > > the
> > > > > > proper response..  a new key pad I think would make these false
> > > > conditions
> > > > > > go away.. I would as a personal preference prefer more response
or
> > > > > positive
> > > > > > action when a keypad action is iniated. this is just a personal
> > want..
> > > > > > albeit false, in my mind I am making a more positive command
> request
> > > and
> > > > > > report..  this might very well be available as a part of
replacing
> > > these
> > > > > > pads with new ones that we might order..
> > > > > >
> > > > > > John compares the keypads between a 3030 and a 3030a  ..  and
true
> > to
> > > > his
> > > > > > findings, my unit is a 3030a and has the bubbly or mushy pad
> faces..
> > > my
> > > > > > hour readings indicate on the left unit 4456 and the right unit
> > 7104..
> > > > I
> > > > > > often think about disconnecting these meters , during quite
times
> or
> > > low
> > > > > > volume, the constant  " Ticking " or pulse action of the meters
> > annoys
> > > > me
> > > > > > somewhat..but I haven't done it yet..  All of my modules are
> sealed
> > > and
> > > > > > unbroken..  S/Ns between the same modules are not all that
close..
> > not
> > > > > using
> > > > > > my sig generator, but using the same signal source and feeding
> both
> > > > units
> > > > > > thru my Stridsberg coupler, all readings are very similar, not a
> > > > > noticeable
> > > > > > or visible difference in meter or audio actions.. Back to the
> > original
> > > > > > problem.. I hung [ Texanise ] suspended the front control panel
> from
> > > the
> > > > > > ceiling and overshifted the operating positions, the receivers
> both
> > > > > respond,
> > > > > > the audio board or pin and wiring is the area where my problem
> is..
> > I
> > > > > > overshifted the control panel both ways and the fault tracked
with
> > the
> > > > > right
> > > > > > control section.. I used  # 12  romex conductors to jumper power
> to
> > > the
> > > > > > respective receiver that I was testing..   so I never got into
> > > swapping
> > > > > > modules , as you know and I found out, the audio driver board is
> > > mounted
> > > > > on
> > > > > > the back of the front control panel.. When I re- assemble this
..
> I
> > > will
> > > > > > swap audio boards, that will pretty much be the final test to
> > isolate
> > > > the
> > > > > > fault.. I have however looked very close at the brown @$%^
> > connectors
> > > > and
> > > > > > each units wiring seems in order..  but I got into the keypad
area
> > and
> > > > now
> > > > > > have 198 parts spewed around that will need re-assembly before I
> can
> > > > > resume
> > > > > > testing for the original problem..
> > > > > > I followed last weeks keypad discussion with keen interest, so
it
> > just
> > > > > > seemed like I was already in that area and partially apart , to
> just
> > > go
> > > > > > ahead and explore this keypad issue, and try and find a solution
> > while
> > > I
> > > > > was
> > > > > > at it..
> > > > > >
> > > > > > All feedback or other 3030a issues will be greatly welcomed, but
> > this
> > > > > pretty
> > > > > > much concludes my 3030A report till Monday sometime after
talking
> > with
> > > > > > someone at Grayhill about replacement keypads.. thanx for the
> > > bandwidth
> > > > > > 73  mac/mc  w5mc
> > > > > > ----- Original Message -----
> > > > > > From: "Al Klase" <skywaves at bw.webex.net>
> > > > > > To: "Herschel McCullough" <w5mc at austin.rr.com>
> > > > > > Cc: <premium-rx at ml.skirrow.org>
> > > > > > Sent: Saturday, June 28, 2003 5:53 AM
> > > > > > Subject: Re: [Premium-Rx] 3030 keypads
> > > > > >
> > > > > >
> > > > > > > Do we know for sure that it's the keypads causing the
> > > > > > > problem rather than lack of proper de-bouncing in the
> > > > > > > electronics?
> > > > > > >
> > > > > > > Al
> > > > > > >
> > > > > > > Herschel McCullough wrote:
> > > > > > > > The Grayhill web site still shows this style that is used
with
> > the
> > > > > 3030
> > > > > > > > ..  some others of you might check it out as well and see
what
> I
> > > > might
> > > > > [
> > > > > > > > very likely ] be overlooking and lets discuss and decide how
> to
> > go
> > > > > > > > forward..
> > > > > > > > and then we say goodbye to the " bubbly "  keypads..  one
> stroke
> > > > > actions
> > > > > > > > will come back to us 3030 drivers..  mac/mc
> > > > > > > >
> > > > > > > > Located 46 Miles due North of the Alamo
> > > > > > > > and 121 Miles due South of the Western White House
> > > > > > > >
> > > > > > > >
> > > > > > >
> > > > >
> > >
> > ------------------------------------------------------------------------
> > > > > > > >
> > > > > > > > _______________________________________________
> > > > > > > >
> > > > > > > > Premium-Rx Mailing List
> > > > > > > > To Post: premium-rx at ml.skirrow.org
> > > > > > > > For Info:
http://ml.islandnet.com/mailman/listinfo/premium-rx
> > > > > > >
> > > > > > >
> > > > > > > --
> > > > > > > Al Klase - N3FRQ
> > > > > > > skywaves at bw.webex.net
> > > > > > > Flemington, NJ 08822
> > > > > > > Web Page:  http://www.webex.net/~skywaves/home.htm
> > > > > > >
> > > > > >
> > > > > >
> > > > > >
> > > > > > _______________________________________________
> > > > > >
> > > > > > Premium-Rx Mailing List
> > > > > > To Post: premium-rx at ml.skirrow.org
> > > > > > For Info: http://ml.islandnet.com/mailman/listinfo/premium-rx
> > > > > >
> > > > > > _______________________________________________
> > > > > >
> > > > > > Premium-Rx Mailing List
> > > > > > To Post: premium-rx at ml.skirrow.org
> > > > > > For Info: http://ml.islandnet.com/mailman/listinfo/premium-rx
> > > > > >
> > > > >
> > > > >
> > > > > _______________________________________________
> > > > >
> > > > > Premium-Rx Mailing List
> > > > > To Post: premium-rx at ml.skirrow.org
> > > > > For Info: http://ml.islandnet.com/mailman/listinfo/premium-rx
> > > > >
> > > >
> > > >
> > > > _______________________________________________
> > > >
> > > > Premium-Rx Mailing List
> > > > To Post: premium-rx at ml.skirrow.org
> > > > For Info: http://ml.islandnet.com/mailman/listinfo/premium-rx
> > > >
> > >
> > >
> >
> >
>
>
>
> _______________________________________________
>
> Premium-Rx Mailing List
> To Post: premium-rx at ml.skirrow.org
> For Info: http://ml.islandnet.com/mailman/listinfo/premium-rx
>

More information about the Premium-Rx mailing list