[HCDX] Technical Discussion : USSR (Russian) SW transmitters never sold to West ...

["mhev" <mhev@xxxxxxxxxxx>]

Technical Discussion : USSR (Russian) SW transmitters never sold to West ...

>From what I can gather, high power SW transmitters in the USSR were all
based on 'Class B' (push-pull) amplification schemes. Class B amplifiers
(for AM modulation) max out at around 60% efficiency. Most 100 kW
transmitters in the west (due to the 1970s energy crisis) long moved over to
PDM, PSM or a combination of the two schemes used by Thales.

The transmitter size was never an issue either -- the transmitters seem to
be about 2 or 3 times the cubic volume of their western equivalents.

Most of the transmitters lacked anything like the fully programmable
automation that became a standard feature in the 1980s. RNZI and several SW
relay sites are unstaffed or minimally staffed due to transmitter
automation.

The USSR pioneered the use of HRS 8 / 8 / 1 curtain arrays, where the west
seems to have settled on HRS 6 / 4 / 1 (HRS 12 / 4 / 1 is used by VOA) and
HRS 8 / 4 / 1 for directive broadcasting.

Yet, I do not expect the Russian SW transmitters to ever be sold in the
west.

China may innovate here -- myself I have been expecting the Chinese to
unvail a HRS 6 / 4 / 1 ALLISS like shortwave transmitter system that is 500
kW capable. I expect the design to be tubeless, period.

The west has begun to ditch tube base transmitters on MW and LW (and FM
too). The module based amplifier system is not hard to design, and only
slightly bulkier (in cubic volume) than tube transmitters. There are enough
Chinese EEs to devise such a transmitter system.

China does actually need such a transmitter system like ALLISS, as it can
aid in jamming.



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