[Elecraft] #3664 is complete

[WK6F]

Thanks for the reminder.  I was comparing the input at the top of the R9/R10
divider at the voltage sense buffer.  The resistors were within the 1%, but
of course not exact.

I'm probably not going to use the battery all that often, so I think the
"float" charge should be sufficient.  The manual says 13.7 +- 0.2 should be
safe, so that should keep things topped off.

I've never had a battery powered HF radio before, so I'll have to explore
the possibilities..........

Ken



-----Original Message-----
From: Don Wilhelm [mailto:w3fpr@peoplepc.com]
Sent: Thursday, August 07, 2003 10:40 PM
To: wk6f@pacbell.net
Subject: Re: [Elecraft] #3664 is complete


Ken,
I trust you did consider the drop of the reverse polarity protection diode
when you concluded that the K2 voltmeter display was low.  If you missed
that one, know that the K2 voltage display function shows the voltage
applied to the inards of the K2 rather than what is connected at the power
jack.  Just a reminder 'just in case'. It sounds like you are as experienced
as they come, so I assume you did it right.  The internal voltmeter is not a
precision instrument, but adequate for what it is supposed to do.

BTW - you may want to consider adding a controlled supply to your battery to
keep it properly topped off rather than through the normal power jack.  Bob
Lewis and I have both addressed the problem.  Bob's solution (and charger)
was published in QST about a year ago, and I have my implementation on my
website www.qsl.net if you are interested.  I have no intentions for further
publication than my website contents!!!

73,
Don W3FPR

----- Original Message -----
From: "WK6F" <wk6f@pacbell.net>
To: <elecraft@mailman.qth.net>
Sent: Friday, August 08, 2003 12:45 AM
Subject: [Elecraft] #3664 is complete


| Hello to the list:
|
| I bought my K2 in large part because of the postings on this list.  Sure
the
| specs were good, but everyone seemed to be having such a good time!  It's
| also nice to be familiar with the innards, just in case.
|
| I got all the options except for high power, and everything went together
| without incident.  I work in a microwave lab, but except for the
convenience
| that fancy equipment offers, I was really impressed how easy it was to get
| the radio going with minimal test equipment.  The Spectrogram setup
routine
| is really great, and it really shows how effective the DSP module is.
|
| One little anomoly:  my voltmeter was reading 0.4 volts low.  Since I have
| the battery, I thought I better know exactly what is applied to it.  I
could
| not find any out of tolerance parts, mis-wires, etc.  The Microchip seems
to
| be using the 5 volt line as the ADC reference voltage (which is 5.12
volts),
| so nothing there.  I ended up replacing R9 on the control board with a
| 1Meg, 10 turn trim pot.  It just fit, so I could tweak the voltmeter (with
| the control board installed) to be dead on compared to my bench DMM.  I
have
| not seen any other comments about this, so maybe it was just a case of the
| voltage divider not quite right.
|
| Since I haven't been on the air for over 20 years, I've got some catching
up
| to do..........
|
| Ken WK6F
|
|
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