On Oct 6, 12:21�pm, Gaius wrote:
AF6AY wrote:
In a box of traded parts I found a cylindrical object labeled
"Clevite Ceramic Filter �TL10D16A" that may be some sort
of IF filter according to very dusty old memory files. �I would
appreciate it if anyone knows of this brand and can give me
an approximate center frequency and, perhaps, impedance
loading of terminations.

Hermetically sealed about 1 1/2" long by 1/4" diameter, leads
coming out ends of metal case. �Unused by appearance of
end wires. �Perhaps 30 to 40 years old? �Trader had no idea
where he got it (probably in a trade of his).

Clevite is an old company and was purchased by Gould
Electronics some time in the late 1960s. �Can't find anything
on this part in web search now.

My thanks for reading. �If anyone has any info, feel free to
post it privately or publicly.

73, Len �AF6AY

I've got one which looks identical, but with a different part number
(TL6D11:A). Mine is a 455KHz centre frequency, 6KHz filter which was
used as the AM filter in the UK/PRC-316 radio. From the circuit, I'd say
it should terminate in 1K ohms.

Clevite was a UK company, based in Southampton, and part of the Brush
Electrical group. They specialised in ceramic filters - and seem to have
been one of the first commercial suppliers of these. I've got other
equipment which uses Clevite filters, and I can assure you these are not
� cheap alternatives to crystal filters - they are high grade components
in their own right.

I'll bet your item is on one of the standard IF frequencies - try
100KHz, 455KHz, 1.4MHz, 5MHz etc.- Hide quoted text -

Thanks to a kind person who supplied me with Clevite catalog data
plus some other Clevite literature, I correctly identified my
Clevite TL-10D16A filter. It has a 455 KHz center-frequency,
-6 db bandwidth of 10 KHz, -60 db BW of 16 KHz. 1500 Ohms input
and output impedance. Insertion loss about 7 db. Data from
Clevite Bulletin 94012 dated Octover 1961. Bench testing shows
a fairly flat passband and very steep skirt attenuation. In a
couple of weeks I might have access to better instrumentation to
quantify its response characteristics.

Clevite was located at 232 Forbes Road, Bedford, Ohio, known in
Clevite Electronic Components, a division of Clevite Corporation,
Cleveland, Ohio. By 1969 they were at the same address and
known as "Gould Piezoelectric Division" with a zip code of 44146.
Piezoelectic devices had been in production since 1959. Whether
it was later acquired by a UK firm is unknown on what I have.

One of the interesting bits of information was a data sheet on
Clevite "Identical Resonators" which contains 10 tables of ladder
filter arrangements from 2 to 8 resonators as bandpass filters
using only capacitors as coupling elements. That might be
applicable to quartz crystal resonators.

73, Len AF6AY