[Elecraft] Newbie K2 questions

[W3FPR - Don Wilhelm]

Tom,

Question 2 -- Do not put the 5 watt T4 winding on your K2 unless you are 
strictly CW and QRP.  With this mod in place, the K2 finals are not 
sufficiently linear for SSB, and when the occasion arises when the drive 
must be above 5 watts, the efficency is worse than with the standard 
winding.  In other words - the mod will not limit the power to 5 watts, it 
only makes the efficency at 5 watts better (and the efficency above 5 watts 
suffers).

Question 4 -- A volt is a volt, so it matters not whether it comes from a 
battery or an external supply.  However, a battery will soon discharge to 
below its freshly charged rated voltage of 13.2 volts, and an external power 
supply usually will put out 13.8 volts.  If you are charging the internal 
battery from the external supply, you will need a supply that puts out 14.1 
to 14.3 volts, the protection diode drops about 0.3 volts (after your A to B 
mods) and for the best lifetime of your battery, it should be maintained in 
a fully charged state.

One other subtle point - the K2 ALC will attempt to produce the power you 
request on the POWER knob, so the net result of a lowered voltage will be 
increased current draw from the supply - of course when running at max 
power, a voltage sag will result in reduced power because in that case, the 
max power is limited by the gain of the K2 circuits.

On your Question 3 -- become 'familiar' with it before doing the upgrades 
and mods, but don't get 'used to it' because you should see significant 
improvement with the upgrades.

73,
Don W3FPR

----- Original Message ----- 
From: "Tom Althoff" <althoff at verizon.net>
To: <Elecraft at mailman.qth.net>
Sent: Thursday, October 28, 2004 5:05 PM
Subject: [Elecraft] Newbie K2 questions


#1117 arrived in the mail today!   I am AMAZED at what is coming out of this 
little box.   I was listening to weak EU's on 40CW at 1900Z and flipping 
back and forth between my Orion and the K2.   Not a lot of difference.   It 
will be interesting to test tonight in the pileups to see how well the 100Hz 
filter works in both rigs.

Question #1:
Is there a way to change the shaft encoder rate?   Not the rate button rate 
but the actual # of pulses per revolution in the hardware or firmware?  I'd 
like to get about 2.5Khz per rev.  Right now I can choose between 1.0Khz and 
5.0Khz.

Question #2 for K2/100 owners:
How much output can you get with the K2 running 5 watts into the K2/100? 
I'm considering the 5W at full scale mod for the K2 but might like to swap 
out the cover with the battery pack and auto-tuner for the 100W module to 
drive my amp.   If I could get 20-30W out of the K2-100 with the K2 running 
5W that would be great.

Question #3:
I have the AtoB, matched crystals, keyclick mod, KAF2  etc etc on their way. 
I'm open to suggestions.   Should I dig in and install the mods right away? 
Or should I relax and enjoy the radio for a while and get "used" to it 
first?   If I get used to it, will the matched crystals, KAF2 and other mods 
be a dramatic improvement compared to the basic #1112 which only has the 
NB/SSB/Auto-Tuner options in it.

Question 4:
When running on a fully charged internal battery can you get the same 
ammount of power out as you do on a fixed external supply?   Just curious.

Oh... The stock knob is gone.   The previous owner had a nice ridged knob 
with a spinner grip installed on the rig.   But I had an old knob from an 
Ampex VPR-3 1" broadcast videotape machine whose diameter just meets with 
the bottom edge of the K2 and only slightly covers the lables for the ATT 
and A VFO.   It is heavily weighted and the knurled edge is thicker than an 
ordinary knob, even deeper than the ones on the Orion, plus it's tapered 
which is unusual and feels great for rolling your fingers around the outside 
edge as you tune.   Will take a pic of it if anyone is interested.

This is a great list!   Many people answered my probe pic questions and I 
have a pair of color photos of the actual probes.   Thanks to all who 
replied directly.

73 de one happy K2 camper!   BTW...When my wife saw me take the K2 out of 
the box she remarked "What a cute little pooter!" a phrase she normally 
reserves for newborn infants and puppies. 8-)

Tom K2TA
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