WA8ULG
- Ted
Parks-Flagstaff,
AZ
Back to
Phoenix AM Page
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Latest
addition to the WA8ULG menagerie is an Arizona-produced Kachina 505DSP
transceiver. This unit incorporated many features later made
famous by SDR's and IF-DSP commercial radios. (Click here or image at left for photographs) |
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The
current Big Project at WA8ULG: converting a Collins 820 D2 1-kW
broadcast transmitter to HF operation on 160, 80 and 40 meters. The 820
D2 ("The Rock") runs a pair of 5-500's in the final, modulated by a
pair of 5-500's. |
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The Tank is a Pi-L using an effective 1100 pF Plate C, 15 uHy, motor-driven variable L and 4000 pF Load C. The coil on the floor of the tank box is the L of the Pi-L; it is fixed in each band. The PA Tank covers 160/75 and, tentatively, 40. The Plate C is a 2000 pF in series with the 4000 pF vacuum variable that nicely opens the range up over the nominal tuning for 160 and 75. When typically run at 3855kHz, component values are: 400 Pf Tune, 5uHy and 1700 Pf Load. |
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Driver
input circuitry: A Philips PM-5192 Synthesizer is used as the
oscillator. It comes into the box at TTL levels.
A 74xx something drives a 2N3866 that, in turn, drives an
MRF-150 FET which drives the final grids through the input
transformer. The 160 input transformer is the original coil cut
down; the 75 coil is new and on the Delrin pier shown to the
right. Everything switches, the primary on the left side of the
relay and the secondary on the right side. The 40-meter section is yet
to be installed. (Click here for larger photo ~100K) |
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The
Tuning and Loading controls: The two multi-turn knobs control
the
plate-tuning cap (top) and the loading cap (bottom). The
bat-handle switch in the old PA tune hole operates in conjunction with
the little edgewise meter to control and follow the Pi inductor (15
uHy). The front panel unlabeled knob to the right of the load
multi-turn is the band switch. (Click here for larger photo ~100K) |
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Posthumous Statement
by Art Collins,
W0CXX, Concerning This Modification |
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A
subassembly in the Nye-Viking tuner falls victim to the
plasma-generating CW power of "The Rock", as well as its asymmetric,
positive-modulation capability. Click here for larger picture |
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The
latest addition is a Radio Engineering Associates AMM-HF1 modulation
monitor, situated between the Collins 51J4 receiver and the Philips
frequency synthesizer. Click here for larger picture |
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Click on Icons at left to see Mod Monitor and 51J4 in action with WWV signal. | |
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A product shot of the REA AMM-HF1. This unit displays both positive and negative modulation levels on the two, green LED "meters". It can be used to measure transmitted and received signals, although the latter requires additional IF amplification. Click here for larger picture Click here to go to the REA website |
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Modulation
Monitor
Scopes for
free (almost)
Click
for details |
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The
complete WA8ULG AM rig: (r-l) receiver/mod monitor/synthesizer
(vfo); 820D2 xmtr; audio rack. Click here for larger picture |
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The
audio rack: GR 1931 modulation monitor, Shure Audio Master mike
preamp/driver, decade-adjustable audio pad and a 3-band, IMP-3
compressor/limiter. Click here for larger picture |
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WA8ULG
at the mike. 5-500 finals and modulators shown, as well as modded
RF-driver circuitry. Click here for larger picture |
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WA8ULG
at the mike of a Clegg Zeus / Interceptor combination owned by his
local club back in the 1960's. Ted now owns a Zeus and
Interceptor, courtesy of W7MD, but has substantially less hair. Click here for larger picture |
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FORT TUTHILL redux |
WA8ULG leads the charge to return the ARCA hamfest to Flagstaff (Ft. Tuthill). Read all about it here.... | |
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"Here is the new 32V3 I
captured from KBLOQ with a 75A3-- a pair of three's. cute little
1"
Millen for mod scope and a new eBay EV 719 to look like the 50s" - Ted
WA8ULG This is the operating position in 'Studio B', the horse house. Click here for larger picture |
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The
big snowstorm of 2010 hits the high-prairie QTH of WA8ULG and the OM
and XYL are delightfully snowbound. The drifts almost cover the
door and windows of the horse house, aka 'Studio B', about 300
feet from the main house. Click here for larger picture |
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Ted
takes the measure of one of the two modulation transformers used by
WLW's 500 kW broadcast transmitter. It gives the term "heavy metal" a
whole new meaning. Click here for larger picture |
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