ELECRAFT KPA3 Spezifikationen PDF herunterladen (Seite 6)

From January 2009 QST © ARRL

Figure 5 — Interior view of the

K3/100. The 100 W output stage

is shown in the center rear. The

subreceiver occupies the

L shaped enclosure ﬁlling the

front portion of the inside of

the radio. Removing the two

knurled nuts and three miniature

coax connections allows

the subreceiver to be easily

removed to add main receiver

rooﬁng ﬁlters, for example.

Figure 4 — The rear panel of the K3/100 includes two antenna

connectors, provisions for a transverter, separate receive

antenna or preamp, and various accessory connections.

notable is a zero-beat CW tuning indicator.

Push CWT and the upper end of the S-meter

bar on the display becomes a zero-center

tuning meter. It works well, even for surpris-

ingly weak signals. Perhaps even better — if

CWT is on, pushing SPOT automatically zeros

the received signal in your passband. This is

important to take advantage of the razor sharp

selectivity provided. If the received signal is

not exactly centered in the passband, drop-

ping the width to the tightest settings could

make the signal disappear.

An internal memory keyer is provided

with rear panel connections for paddles. A

rear KEY jack is also provided — both are a

convenient

⁄4 inch size, by the way. I finally

have an easy way to hook up both sides of my

ancient Brown Brothers CTL model combina-

tion straight key and paddles. The straight key

is handy for trimming up the tune of my linear,

as well as for ARRL Straight Key Night.

Speaking of linear amplifiers, a menu

choice provides for RF output timing delay.

You can set the timing to accommodate the

switchover delay of your break-in capable

linear. Mine works flawlessly with full break-

in. For those using contest software, a menu

selection can set the RS-232 computer con-

nection control leads to key the transmitter

under command of the PC.

The K3 break-in switching is as smooth

and quick as any radio I’ve used. Major CW

controls, including KEYER SPEED, PITCH

and MONITOR LEVEL are front panel rotary

controls, as they should be on a serious CW

radio. The MONITOR LEVEL is independent

of the AF GAIN setting, for which my ears

are grateful.

SSB Features

For those who don’t like being con-

strained by the usual SSB filter bandwidth,

extended SSB (ESSB) is provided, currently

to a 4 kHz width. ESSB requires the optional

6 kHz filter. The K3 provides a single eight

band, ±16 dB/octave audio equalizer contour.

Having one setup for DX and contesting and

a separate setup for ragchewing would seem

like a beneficial addition. A similar, but

separate, equalizer is available for receive.

In this case one per mode might be handy.

Recent firmware has added a noise gate

feature to SSB transmit. This allows you

to set a threshold to eliminate background

noise — especially handy if you are using

compression, or have a noisy amplifier fan,

for example.

The VOX is among the best I’ve used. It

picks up before the first syllable is over, the

ANTIVOX is not fussy and the VOX HOLD delay

is front panel adjustable. A monitor function

is provided, the level setting sharing the front

panel CW MONITOR knob while in voice

modes. This is best used with headphones to

avoid acoustical feedback, but is very handy

for setting up the equalizer, gain, compres-

sion, noise gate and other transmit controls.

The front panel MIC connector is the

common round 8-pin type, wired almost to

the Kenwood standard. If you use an electret

mic, the bias connections need adjustment. In

addition, there is a rear panel

⁄8 inch phone

MIC connector, as well as an

⁄8 inch phone

LINE IN connector for sound card or other

external sources. The LINE IN GAIN can be

set independently of the MIC GAIN so you

can move between modes without having

to change your gain settings. Menu settings

determine which of the inputs is active.

There is also a rear panel PTT connector

so if you have a Heil headset, for example, it

and a companion foot switch can be plugged

mode from 0.1, 0.5, 1 kHz through 5, 9 and

10 kHz. The faster settings apply to AM and

FM modes with 9 kHz intended for European

AM broadcasts on 9 kHz spaced channels.

Another menu item sets the steps per rotation

to 100, 200 or 400. I find the 200 step setting

just right, offering 200 Hz, 2 or 10 kHz per

revolution with the 10 Hz RATE and 1 kHz

COARSE setting. The FREQUENCY display

shows the appropriate digits for the resolu-

tion selected.

There are 100 memory locations avail-

able, selected using the VFO A knob. Ten of

these are selectable with a quick two-button

push and I have these set up for band selec-

tion instead of using the BAND up-down bar.

Once on a band, it is possible to have another

two-button sequence move you between your

favorite modes with associated filter and

other settings.

Those Rooﬁng Filters

Many have wondered about the different

roofing filters and how they impact perfor-

mance so they can decide which to order. In

addition to the 13 kHz filter for FM and 6 kHz

filter for AM and extended SSB, we tested

our unit with 2700 and 500 Hz five-pole and

2800, 1800 and 400 Hz eight-pole filters.

Each receiver is limited to five filters at a

time, and there’s a bit of menu setup involved

when you install or change them.

An FAQ on the Elecraft Web site goes on

to explain that the K3 uses hardware AGC

after the roofing filter and before the DSP.

Signals inside the roofing filter’s bandwidth

will desense the receiver if they exceed about

S9 + 25 dB, and changing to a 400-500 Hz

filter reduces blocking from signals 1 to

5 kHz away.

The ARRL Lab made a number of measure-

ments with the different filters and the results

are shown in the accompanying sidebar.

CW Features

Elecraft’s roots are in the CW only, por-

table low power (QRP) transceiver market, so

it’s no surprise that there are many features

especially for the CW operator. Perhaps most

1 2 3 4 5 6 7 8 9

Kommentare zu diesen Handbüchern

Keine Kommentare

ELECRAFT KPA3 Spezifikationen Seite 6

Kommentare zu diesen Handbüchern

Verwandte Produkte und Handbücher für Empfänger ELECRAFT KPA3