Empathy List Archives

RN

Ruslan Nabioullin

Sun, Feb 5, 2017 5:20 AM

Hi, any ideas on what the Austron Synchronous Filter 2090A is for? I
couldn't find it in the '88 catalog. I recall seeing some hits for it
in old unclassified DoD R&D publications in the past, wherein it was
used as part of an experimental LORAN reception setup.

-Ruslan

Hi, any ideas on what the Austron Synchronous Filter 2090A is for? I couldn't find it in the '88 catalog. I recall seeing some hits for it in old unclassified DoD R&D publications in the past, wherein it was used as part of an experimental LORAN reception setup. -Ruslan

PK

Poul-Henning Kamp

Sun, Feb 5, 2017 7:58 AM

In message 7fe92930-931a-e086-4e96-a4dcb359ebb8@gmail.com, Ruslan Nabioullin writes:

Hi, any ideas on what the Austron Synchronous Filter 2090A is for?

I belive the idea is that if you have two Loran-C receivers tracking two
different GRIs, the 2090A can blank out the strongest stations pulses
for the weaker chains receiver.

--
Poul-Henning Kamp | UNIX since Zilog Zeus 3.20
phk@FreeBSD.ORG | TCP/IP since RFC 956
FreeBSD committer | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.

-------- In message <7fe92930-931a-e086-4e96-a4dcb359ebb8@gmail.com>, Ruslan Nabioullin writes: >Hi, any ideas on what the Austron Synchronous Filter 2090A is for? I belive the idea is that if you have two Loran-C receivers tracking two different GRIs, the 2090A can blank out the strongest stations pulses for the weaker chains receiver. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 phk@FreeBSD.ORG | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence.

RN

Ruslan Nabioullin

Sun, Feb 5, 2017 8:20 AM

On 02/05/2017 02:58 AM, Poul-Henning Kamp wrote:

I belive [sic] the idea is that if you have two Loran-C receivers
tracking two different GRIs, the 2090A can blank out the strongest
stations [sic] pulses for the weaker chains [sic] receiver.

So it functions sort of as a preselector, one whose universe of
discourse is LORAN-C, for improved reception performance of the receiver
tracking the weaker GRI?

-Ruslan

On 02/05/2017 02:58 AM, Poul-Henning Kamp wrote: > I belive [sic] the idea is that if you have two Loran-C receivers > tracking two different GRIs, the 2090A can blank out the strongest > stations [sic] pulses for the weaker chains [sic] receiver. So it functions sort of as a preselector, one whose universe of discourse is LORAN-C, for improved reception performance of the receiver tracking the weaker GRI? -Ruslan

BC

Bob Camp

Sun, Feb 5, 2017 4:20 PM

Hi

Best guess - it was intended for use in close proximity to a Loran chain transmit
site. The Austron Loran receivers only had about a 100 db dynamic range. If you
needed to operate close to a transmitter … that’s not enough.

Bob

On Feb 5, 2017, at 3:20 AM, Ruslan Nabioullin rnabioullin@gmail.com wrote:

On 02/05/2017 02:58 AM, Poul-Henning Kamp wrote:

I belive [sic] the idea is that if you have two Loran-C receivers
tracking two different GRIs, the 2090A can blank out the strongest
stations [sic] pulses for the weaker chains [sic] receiver.

So it functions sort of as a preselector, one whose universe of
discourse is LORAN-C, for improved reception performance of the receiver
tracking the weaker GRI?

-Ruslan

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and follow the instructions there.

Hi Best guess - it was intended for use in close proximity to a Loran chain transmit site. The Austron Loran receivers only had about a 100 db dynamic range. If you needed to operate close to a transmitter … that’s not enough. Bob > On Feb 5, 2017, at 3:20 AM, Ruslan Nabioullin <rnabioullin@gmail.com> wrote: > > On 02/05/2017 02:58 AM, Poul-Henning Kamp wrote: >> I belive [sic] the idea is that if you have two Loran-C receivers >> tracking two different GRIs, the 2090A can blank out the strongest >> stations [sic] pulses for the weaker chains [sic] receiver. > > So it functions sort of as a preselector, one whose universe of > discourse is LORAN-C, for improved reception performance of the receiver > tracking the weaker GRI? > > -Ruslan > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there.

PK

Poul-Henning Kamp

Sun, Feb 5, 2017 4:34 PM

In message e535a286-2a82-417b-ad9f-a1f1c67928dc@gmail.com, Ruslan Nabioullin writes:

On 02/05/2017 02:58 AM, Poul-Henning Kamp wrote:

I belive [sic] the idea is that if you have two Loran-C receivers
tracking two different GRIs, the 2090A can blank out the strongest
stations [sic] pulses for the weaker chains [sic] receiver.

So it functions sort of as a preselector, one whose universe of
discourse is LORAN-C, for improved reception performance of the receiver
tracking the weaker GRI?

I belive so, yes, but this is based on my reading of the meagre references
in the manuals I've seen.

--
Poul-Henning Kamp | UNIX since Zilog Zeus 3.20
phk@FreeBSD.ORG | TCP/IP since RFC 956
FreeBSD committer | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.

-------- In message <e535a286-2a82-417b-ad9f-a1f1c67928dc@gmail.com>, Ruslan Nabioullin writes: >On 02/05/2017 02:58 AM, Poul-Henning Kamp wrote: >> I belive [sic] the idea is that if you have two Loran-C receivers >> tracking two different GRIs, the 2090A can blank out the strongest >> stations [sic] pulses for the weaker chains [sic] receiver. > >So it functions sort of as a preselector, one whose universe of >discourse is LORAN-C, for improved reception performance of the receiver >tracking the weaker GRI? I belive so, yes, but this is based on my reading of the meagre references in the manuals I've seen. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 phk@FreeBSD.ORG | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence.

TV

Tom Van Baak

Tue, Feb 7, 2017 9:58 PM

Hi, any ideas on what the Austron Synchronous Filter 2090A is for? I
couldn't find it in the '88 catalog. I recall seeing some hits for it
in old unclassified DoD R&D publications in the past, wherein it was
used as part of an experimental LORAN reception setup.

From the data sheet:

The AUSTRON Model 2090A Synchronous Filter is a Loran-C waveform averaging system that extends the range and versatility of the AUSTRON Model 2000C Loran-C Receiver in a variety of time/frequency and propagation applications.

Basically, the Model 2090A obtains a pulse waveform average that is taken over a number of pulse group repetition periods and processed for scope display or stripchart recording.

Loran-C waveform averaging accomplishes two important results:

First, most types of coherent CW interference (communication signals, etc.) may be cancelled to zero in less than a second. This type of interference can be particularly troublesome when recording Loran-C waveforms in conventional ways.

Second, averaging improves the waveform signal-to-random-noise ratio in proportion to the effective averaging time. Thus, it is possible to retrieve and analyze Loran-C signal waveforms that are obscured by atmospheric and manmade noise in the normal 20 KHz or 50 KHz receiver RF bandwidth.

For more details, including photo, specs and principles of operation, see:
http://leapsecond.com/museum/au2090a/

/tvb

> Hi, any ideas on what the Austron Synchronous Filter 2090A is for? I > couldn't find it in the '88 catalog. I recall seeing some hits for it > in old unclassified DoD R&D publications in the past, wherein it was > used as part of an experimental LORAN reception setup. >From the data sheet: -------- The AUSTRON Model 2090A Synchronous Filter is a Loran-C waveform averaging system that extends the range and versatility of the AUSTRON Model 2000C Loran-C Receiver in a variety of time/frequency and propagation applications. Basically, the Model 2090A obtains a pulse waveform average that is taken over a number of pulse group repetition periods and processed for scope display or stripchart recording. Loran-C waveform averaging accomplishes two important results: First, most types of coherent CW interference (communication signals, etc.) may be cancelled to zero in less than a second. This type of interference can be particularly troublesome when recording Loran-C waveforms in conventional ways. Second, averaging improves the waveform signal-to-random-noise ratio in proportion to the effective averaging time. Thus, it is possible to retrieve and analyze Loran-C signal waveforms that are obscured by atmospheric and manmade noise in the normal 20 KHz or 50 KHz receiver RF bandwidth. -------- For more details, including photo, specs and principles of operation, see: http://leapsecond.com/museum/au2090a/ /tvb

time-nuts@lists.febo.com

information about the Austron Synchronous Filter 2090A

Second, averaging improves the waveform signal-to-random-noise ratio in proportion to the effective averaging time. Thus, it is possible to retrieve and analyze Loran-C signal waveforms that are obscured by atmospheric and manmade noise in the normal 20 KHz or 50 KHz receiver RF bandwidth.