The BTA-5F used three-phase power and a full-wave rectifier with 6-each 8008
mercury-vapor rectifier tubes. Don't remember the size of the filter
capacitors, but they weren't extraordinary as I recall. The filter choke was
about as big as a full-sized microwave oven. Full-wave rectified, three-phase
power isn't hard to filter.


Some RCA 5Ks and 10Ks were designed as two-phase, and, consequently, have four
rectumfier (sic) tubes.

This might be called a "four phase" rectifier in the same way as a three-phase,
full-wave rectifier is called a "six phase" rectifier.

Oh, these 5Ks and 5Ks actually run on three-phase feeders, as the primaries are
connected in a Scott-T, while the secondaries are connected as two-phase.

Buffalo and Philadelphia (including Camden, and undoubtedly RCA's plant as
well) were the last hold-outs of two-phase power in the U.S.

In article , inch (Peter
H.) wrote:

Some RCA 5Ks and 10Ks were designed as two-phase, and, consequently, have four
rectumfier (sic) tubes.

They were actually Thyratrons used as rectifiers, the plate voltage, and
hence power output could be adjusted by varying the firing angle of the
grid, sort of like the modern light dimmer in your dining room.

This might be called a "four phase" rectifier in the same way as a
three-phase, full-wave rectifier is called a "six phase" rectifier.

To avoid confusion I call it a 4 pulse, or 6 pulse rectifier, as the case
may be.

Oh, these 5Ks and 5Ks actually run on three-phase feeders, as the primaries
are connected in a Scott-T, while the secondaries are connected as two-phase.

Yes.

Buffalo and Philadelphia (including Camden, and undoubtedly RCA's plant as
well) were the last hold-outs of two-phase power in the U.S.

Are you saying that is what inspired RCA to build these transmitters with
a two phase feed to the rectifiers, I think they were the BTA-5G, BTA-10G,
BTA-5H, and BTA-10H?


Regards,

John Byrns


Surf my web pages at, http://users.rcn.com/jbyrns/

Buffalo and Philadelphia (including Camden, and
undoubtedly RCA's plant as well) were the last
hold-outs of two-phase power in the U.S.

Are you saying that is what inspired RCA to build these transmitters with a two
phase feed to the rectifiers, I think they were the BTA-5G, BTA-10G, BTA-5H,
and BTA-10H?


I am hypothesizing that RCA utilized some ingenuity and well-known (to
two-phase aficionados) engineering techniques to make an unusual box which had
some unique cost-savings features.


To avoid confusion I call it a 4 pulse, or 6 pulse rectifier, as the case may
be.


However "incorrect" it may be, the literature calls these "four phase" and "six
phase".

"Twelve phase" is also employed. This is really three-phase, full-wave, using a
"zig zag" transformer.