[Elecraft] Re: purchase decision [K2/100 as ARES/ermergency rig]

[wayne burdick]

Hi Scott,

Thanks for your interest in the K2/100. I'm sure you'll get many 
responses to your posting, but I thought I'd give you my perspective, 
too:

> I'm looking for a backup, portable, ares rig...

I think you'll find the K2 well-suited to an ARES application. It's 
quite small, and weights just 5 pounds with the KPA100 module or the 
internal battery installed. Current drain is extremely low for a 
high-performance transceiver: less than 0.5 amp on receive with the 
KPA100 module installed. If you ever had to run from a battery and/or 
solar panel, you'd be on the air for a long time.

The K2/100 also has a companion automatic antenna tuner (KAT100) that's 
quite rugged and can match a very wide range of ad-hoc or emergency 
antennas. The KAT100-1 (slim package) can be installed directly 
underneath the rig, forming a compact package.

Another unique feature of the K2/100 is that it has two DC input jacks: 
an APP connector for the usual 20 amp supply, and a DC barrel jack for 
powering just the 15-watt basic radio. If you have a backup supply (say 
a small battery) connected to the barrel jack, and the 20 amp supply 
goes down (due to loss of mains, etc.), the rig will keep right on 
running at the 15-watt level. This is totally seamless -- you don't 
even have to unkey the mic. The LCD will flash "NO PA P.S." (no PA 
power supply).

>
> 1  At low dc voltage, What is the power output of the k2/100?

The basic K2 is unusual in that it's designed to provide stable 
operation from as low as 9 volts. Power will automatically roll back 
(due to the programmable current limit) from 15 watts to between 2 and 
5 watts as you approach this lower voltage limit. When using the PA, a 
higher supply voltage is recommended (11 volts), but you'll be able to 
use the PA even at the end-of-life voltage for a gel-cell (around 10 to 
10.5 V) in a pinch. The K2 has a built-in voltmeter for monitoring 
supply voltage, so it you suspect the voltage is low, you can check it 
periodically and adjust the POWER control downward manually. You might 
experiment with this ahead of time to gain some experience with 
low-voltage operation.


> 2 Has anyone used the k2/100 on pactor III? Are the ssb filter widths 
> an issue?

The K2 meets the turnaround times for Pactor, although I haven't used 
the rig in this mode myself. The SSB filter bandwidth should suffice 
(about 2.2 to 2.4 kHz). This bandwidth was selected to provide good 
"punch" when operating at low power.


> 3 The stock radio has 10 memories? Is there a way to expand this?

There are actually 20 memories: one per band that saves the last VFO 
A/B setting on each, and 10 general-purpose memories. The modest number 
of memories reflects the K2's low-power/high-performance pedigree; the 
rig has a very efficient microcontroller that keeps internal RFI to a 
minimum as well as drawing just a few mA.

You can use the memories for scanning, either continuously from VFO A 
to B, or for channel-hopping, e.g. among the five fixed frequencies of 
the 60 meter band. The VFO knob can even be programmed to channel hop 
manually, especially useful on 60 meters and with VHF transverters.

If you control the radio from a computer, you can have unlimited 
memories, since the computer can store and retrieve them and program 
the radio. A number of radio-control and logging programs have been 
adapted to work well with the K2.

73,
Wayne
N6KR

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