I guess the Chinese firm of BBEF Beijing can deliver such final tubes to far eastern Massachusetts US center.
But is also a hardware insurance matter of the Ampegon revolving beast ?
Thomcast-Ampegon delivered their first high power SW gear to Quivican China site already in 2004 year.
And now at present the RTC Chinese have some 100 to 150 most modern transmitters on shortwave in service. Built-up with own China mainland tube clones ...
- - -
About the older tx and ITU #805 antennas at WBCQ center:
ITU Geneve antenna type list on shortwave
WBCQ 50 kW into log-periodic horizontal at 11 dBi gain.
805 LPH18/36.5/32.2/16.7/1.4/13.2/200
against WBCQ 300 / 500 kW
into 4 x 4 dipols curtain array, revolving Ampegon antenna on 9330 kHz, mostly gain by 18 to 21.5 dB {against simple horizontal dipole}
Ampegon
216 AHR(S) 4/4/0.5 21.5 dB gain.
End-fed dipole array with aperiodic reflector.
Curtain arrays of co-linear horizontal half wavelength dipoles arranged in a vertical plane in order to reduce the beamwidth of the main lobe and hence increase the directivity of the antenna. Directional patterns are generally obtained by the use of an aperiodic reflector. An periodic reflector is normally a screen consisting of horizontal wires which act as an untuned reflector.
The front-to-back ratio of an aperiodic reflector depends on such factors as: number of wires per wavelength, wire gauge, distance between radiating elements and reflector, and size of reflector. To achieve a front-to-back ratio, which approaches the gain figure of the antenna would require a screen density of about 40 to 50 wires per wavelength for the highest operating band of the antenna.
In practice a number of antennas of this form can be operated over a maximum of five consecutive broadcasting bands giving an operating frequency range of up to 2:1. This range is limited by the performance of the radiating elements.
WBCQ July 18 at 10.50 UT
7489.926 USA WBCQ S=7 in MA east coast at 23.05 UT, good sounding oldies.
7490v nothing at 10.55 UT.
9329.947 USA WBCQ broadcast of WLC in Portuguese language, S=5 at 23.13 UT.
9329.939 July 19.
6159.891 USA WBCQ most modern pop mx program, at 23.16 UT, S=9+20dB strong.
6159.896 July 19.
4789.981 July 19.
4789.976 USA Tentativelly WBCQ settled here, move from 5130 kHz acc
their FCC schedule ?, At 23.31 UT S=9+20dB in MA state, 14 kHz
wide excellent signal of their old 50 kW transmitter.
clearly deviating with very inaccurate transmission frequency.
Terrible lamentation audio also male voices, and piano player
in between. A terrible recording performance of TOMinistry?
73 wolfie
