VE9AA et. al. de N4KG -
In my humble and biased opinion, the TS-830 is one of the "Best Buys"
from the 80's (if not the BEST period). I own three of them and I love
'em! Some consider it to be the KWM-2 of the 80's.
The primary difference between the 530 and 830 is that the 530 only
has a single IF (and therefore single IF filter) at 8830 KHz. The 830
has two IF's (at 8830 and 455 KHz) allowing cascaded filters,
variable bandwidth tuning (VBT), and RF Speech Processing (very
effective).
Because of having tube finals (6146's with a 12BY7 driver), the TS-830
produces an extremely clean signal with no wideband phase noise
like most (all?) solidstate finals. This is especially helpful in multi-
transmitter stations.
Bandchanging can be simplified by placing a cut-to-fit piece of 3X5
card behind the tuning controls and marking the appropriate settings
for each band. The drive control is tuned to the center of each band
when the pointer is set straight up. Since I prefer CW, I readjusted
my driver coils such that when the pointer is at the 9 o'clock
position, it is peaked at 025, 25 KHz above the bottom edge of each
band, thus eliminating the necessity to retune it for CW bandchanges.
The MIC and CARRIER controls can be used to adjust the power
output to any desired level which is useful for QRP operation.
There is a bank of 4 pins on the IF board which select the desired
filter combination for CW Narrow. If both CW filter slots are filled,
it is often desirable to switch between a single (use the 8830 filter)
or cascaded (500 Hz) filters. This can be done by using the (useless)
Frequency Hold Pushbutton on the front panel. (This switch holds the
displayed frequency but if you tune the VFO, the tuned frequency
will change, but not the display...Who needs it!)
For most purposes, cascaded 500 Hz filters provide all the selectivity
needed EXCEPT on 40M CW during DX contests. Then it is useful
to have one narrow filter. I prefer having the first (8830 KHz) filter
as
the narrow filter since it then protects the 8830 to 455 mixer from
strong close-in signals and prevents intermodulation products from
being generated.
One interesting idea which I have not implemented in practice but did
verify, is that it is quite simple to insert a remote receive-only IF
filter
in the 50 Ohm line between the RF board and the IF board. Since the
line is 50 Ohms, a cable can be run from the RF board to an external
box which can be designed to match any 8830 KHz filter(s) to 50 ohms
input/output and then run back to the IF board. Such a box could
house a 1.8 KHz SSB filter and either a 500 or 300 Hz CW filter (or
both), and even another 2.4 KHz filter, and a through position. Since
this is the RX line, there would be no change to the transmit audio if
a narrow SSB filter was selected. A 1.8 KHz filter makes for a very
nice CW bandwidth in conjunction with the VBT, but has wide skirts
which I find very useful for rapid tuning of the band during day-to-day
operation. (One of my 830's has a 1.8 KHz first IF filter (8830 KHz)
and 300 Hz (8830) and 500 Hz (450) filters. This configuration cuts
into my transmit audio and I find that I do not like the narrow CW filter
for daily use because it requires slower tuning of the band. An
external filter box would be the perfect solution. (OK, I'm lazy and
prefer to USE the radio to working ON the radio when I get home!)
There is a DIN plug on the rear panel for a (VHF) receive converter.
This plug interrupts the RX antenna line which is the ideal way to
access the RX input for separate receive antennas. I place the
common position of a 5 position switch on the RX line and the line
from the TX antenna relay to one of the open positions. That way I can
quickly switch between the transmit antenna and 4 Beverages.
One CAUTIION: The RX input coil is only 7 mm square and uses
very small wire that can only handle around 6(?) VRMS at the input
which is less than ONE WATT. (A far cry from my old 75A3 which has a
warning on the rear panel that reads "Do Not Exceed 50 VOLTS Input"
(50 WATTS!). After replacing the 830 RX input coil a few times,
I have installed "protection boxes" on the RX input line (via the
converter plug) of all my 830's. These boxes consist of a 22 Ohm 2 watt
resistor
followed by two stacks of 4 PIN diodes to ground (one stack for each
polarity) which have prevented recurrent failures. Any low capacitance
fast switching diode should also work well. Use at least 4 in each
stack.
Having used both the TS-930 (early version) and TS-940, I find that
I prefer the 830 RX to both of them. The early 930 suffered from
a constant low level tone right in the center of the CW passband which
drove me crazy after hours of contesting and the wide (2.7 KHz) SSB
filters made it impossible to ever find a "hole" in the bands during
contests. The 940 sounded 'harsh' on CW and suffered from poor PLL
phase noise which resulted in annoying incoherent noise on crowded
bands with strong signals.
Another testimonial comes from K3ZO who, until just this year, used a
TS-830 for all of his TOP-TEN finishes in the major DX contests.
de Tom - N4KG
ARRL Technical Advisor
(ex: Collins Radio Company engineer 1966-1969)
.
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