Color Laserjet 5 Available

Bob Bruhns bbruhns at
Thu Jan 3 18:42:05 CST 2008

Thanks, Frank!  The inkjets are soo darn thirsty; a good laser is much more economical, actually, and the 5000 is a great machine
capable of 11x17 work.  This is a banner day in Bobland!!!

I do those mods to various radios all the time at work.  Any documentation will help, but the technology of the 80s was pretty
straightforward.  Almost surely two-point synthesizer modulation, if the radio was capable of digital squelch, which I believe that
vintage was.  I'll make sure the transmit bottom end goes good and low, and that the TX audio top end is appropriate for 9600 (will
have to bypass the internal post-clipper LPF for that), and I'll add EQ on the receive top end if the 9600 eye pattern looks at all
squeezed.  Although I don't know what data speed you'll be running.  Might want to optimize for 4800, that would be easier, but if
they can do 9600 then they might as well.

I use a commercial bit error rate tester at work, and it has three 'depths' of test pattern... I guess it's time to figure out what
they really are, and duplicate them, and figure how to synchronize to the received bitstream and count bit errors with those sorts
of patterns.  What would be really nice would be to be able to distort the modulation pattern in a few different ways during test,
and see if everything is about centered on optimum.  Transmit is easy to get virtually perfect, but receive can be really wierd.  I
find that at speeds like 9600, if I want reliable indication of BER down around 1E-7, it takes time... so, I go for a pattern that
is obviously clean, and then document the performance.

  Bob, WA3WDR

----- Original Message ----- 
From: "Metavox LLC" <metavox at>
To: "Bob Bruhns" <bbruhns at>
Cc: "Tacos" <tacos at>
Sent: Thursday, January 03, 2008 7:02 PM
Subject: Re: Color Laserjet 5 Available

> Bob,
> Your name is on this fine beast.  I cannot think of a more deserving and
> good home for it.
> Your help on the Midland data interface would be much appreciated.  I
> have scanned the manual for one of the models and I think I should get a
> manual for the other model and scan it also.  The manuals seem almost
> essential to such a mod.
> We also could use a data link tester to generate a test data stream and
> test for it on the receive end.  It used to be we built a special
> purpose bunch of logic but I think today a DSP or microprocessor
> development kit with some simple programming would be easier and more
> flexible.
> Frank
> Bob Bruhns wrote:
> > Frank, I would sure like that, but I feel that I should then do something like come up with the digital data interface
> > for the Midlands or something... has that been done yet?  If not, I'll do it.
> >
> >    Bob
> >
> >
> > ----- Original Message ----- 
> > From: <fgentges at>
> > To: "Tacos" <tacos at>
> > Sent: Thursday, January 03, 2008 4:44 PM
> > Subject: Color Laserjet 5 Available
> >
> >
> >> Tacoistas,
> >>
> >> I have a used HP Color Laserjet 5 printer that I no longer need.  Last
> >> time I fired it up it worked.  I have downloaded some manuals on it.
> >>
> >> It is big and heavy but the price is right.... Free to good home.
> >>
> >> Frank K0BRA
> >> _______________________________________________
> >> Tacos mailing list
> >> Tacos at
> >>
> > _______________________________________________
> > Tacos mailing list
> > Tacos at
> >
> >
> _______________________________________________
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