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The Simple Superhet Transceiver
SST
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The SST is an optimized, superhet rig with an extremely low parts count
(only 80 parts, vs. 100 for a 38-special and 120 for a NorCal 40A).
This may be the easiest to build superhet ever, and it comes with a miniature
custom enclosure, less than half the size of a NorCal 40A.
SST Features:
- 2 watts out (varies w/band and
supply voltage), adjustable down to zero
- fast, clean QSK with transmit
monitoring
- 3-pole crystal filter at a low I.F.
(about 4 MHz)
- built-in, no-adjustments AGC with
received signal indicator LED
- stable VXO coverage of 10 to 20 kHz
using varactor tuning (range varies w/band)
- very low current drain--about 15mA
- stable operation from 10 to 16VDC, or
internal 9V lithium battery
- works with the Wilderness KC1 keyer/
counter and BuzzNot noise blanker.
- both the KC1 and BuzzNot can be installed inside the SST
- all controls, connectors, and parts
mount on a single 3.0" x 3.4" PC board
- 1.5"H x 3.2"W x 3.5"D custom
enclosure (supplied unfinished)
RECEIVER:
A superhet with a sharp, three-crystal filter, operating at a low I.F.
(around 4MHz). The receiver uses a novel AGC circuit employing a single
LED as both the detector and signal indicator.
The AF gain control and headphone jack are on the front panel. The RF gain
is rarely used in the SST, so I put it on the back.
TRANSMITTER:
The Transmitter has *really* fast, exceptionally clean (totally
thump-free) QSK with TX monitoring, as in the '40A. Power output is around
2 watts on all three bands with a 13.8V supply, and proportionally less at
12V or 9V. Power out is adjustable down to zero.
Varactor-controlled VXO rather than a VFO with excellent stability.
Frequency coverage (approximate):
40m 7.032 - 7.042
40m/novice 7.105 - 7.115
30m 10.105 - 10.120
20m 14.046 - 14.064
VXO range can be increased by switching in a second varactor. All VXO and
I.F. crystals used are *standard* frequencies available from Digikey.
The custom enclosure is about 3W x 3.5D x 1.5H", and is supplied
unfinished. Since the box is so small, we use .050 aluminum to reduce
weight. (With a KC1 on the top and an internal 9V lithium battery, the SST
makes a great TFR.
PRICE AND KIT INFO:
The SST is supplied only as a complete kit -- no partials.
The kit includes a high-quality double-sided and silkscreened PC board; a custom,
unfinished .050 aluminum enclosure with hardware; all controls, connectors,
knobs, rubber feet, etc.; detailed manual; and all parts for your choice of
bands.
The price for each complete SST is $90.
ORDERING INSTRUCTIONS
1. Please enclose $90 per kit ordered.
2. For each kit ordered, you must specify the band: 40m, 40m/novice, 30m,
or 20m. (Remember, this is a VXO-based transceiver, so the rig does not
cover the entire CW band. Approximate coverage is: 40m, 7.032-7.042;
40m/novice: 7.105 - 7.115; 30m, 10.105-10.120; 20m, 14.046-14.064. Other
ranges are possible with small modifications.)
3. Missouri residents must add your local state sales tax.
4. Shipping charges are extra: $6 U.S., $8 Canada/Mexico, $20 DX (other).
This is a per-kit shipping charge.
5. Please make out checks to Wilderness Radio. We'll also
need your name, call, address, phone number, e-mail address.
6. Send U.S. funds only (checks drawn on US banks, or an international money
order) to:
Wilderness Radio
P.O. Box 3422
Joplin Mo, 64803-3422, USA
For more information, call Bob at:
Wilderness Radio
CREDIT CARDS NOT ACCEPTED