[time-nuts] OT: UK's atomic clock 'is world's most accurate'

[David J Taylor]

From the BBC: UK's atomic clock 'is world's most accurate', see:


 http://www.bbc.co.uk/news/science-environment-14657002

Cheers,
David
--
SatSignal software - quality software written to your requirements
Web:  http://www.satsignal.eu
Email:  david-tay...@blueyonder.co.uk 


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[time-nuts] Active LORAN antenna

[Ulrich Bangert]

Gentlemen,

my friend Frank and I both miss the matching actice antenna for our
Standford Research FS700 Loran frequency standards. We also do not have a
schematic of it. Nevertheless we have tried to re-engineer the circut from
the part's list and the circuit description in the FS700 manual. Our result
is shown in the accompanying schematic.pdf. 

The generator in the left in conjunction with the 10 k resistor represents
the expected high footpoint impedance of the very short (3 m) antenna. The
VDD in the right in conjunction with the 100 ohms resistor represents what
it believed to be inside the FS700.

Not shown here is a 100 k resistor that may be included between the filter
output and the 7 k resistor to form a 30 dB divider together with it. Also
not shown is a 390 micro henry inductance which's impact is not to be found
in the circuit descripion. Also not shown is a small neon bulb for
overvoltage protection. 

The ac analysis shows that the overall filter function is well around 100
kHz. But it seems as if the fet (a 2N5991 in the original) would not have
enough gain to counteract the overall damping included in the front end let
alone to deliver some additional gain for the receiver's front end. 

We both feed the receiver currently with dipoles for 80 m ham radio and a
resistor that makes the receiver think the active antenna is connected. The
receiver has a possible total of 130 dB gain and my receiver says it uses 94
dB gain while Franks receiver says it uses 102 dB gain. The noise margin is
also a bit better on my location. However, if one looks at the manual f.e.
at page 17 one could get the impression as if a receiver gain of 75 dB may
be considered much more normal as our values. Instead of improving the
reception everything gets even worse if the active antenna is connected. I
should also note that my qth is only 200 km away from SYLT (our German Loran
station) while Frank is even 70 km nearer to it.

Questions:

1) Anyone an idea what we are possibly doing wrong?

2) Anyone an idea for the 390 micro henry inductor?

3) Anyone own the original schematic?

TIA for your help   

Ulrich Bangert
www.ulrich-bangert.de
Ortholzer Weg 1
27243 Gross Ippener 


Schematic.pdf
Description: Adobe PDF document


ACAnalysis.pdf
Description: Adobe PDF document
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Re: [time-nuts] Racal 9420 OCXO

[Robert Atkinson]

Hi Rob,
That's interesting. Racal Instruments were agents for Oscilloquartz and Ball 
Efratom. Their Rubidium standards have Efratom FRKs in them.
 
Robert G8RPI.

--- On Thu, 25/8/11, Rob Kimberley  wrote:


From: Rob Kimberley 
Subject: Re: [time-nuts] Racal 9420 OCXO
To: "'Discussion of precise time and frequency measurement'" 

Date: Thursday, 25 August, 2011, 22:13


I seem to remember Racal in the UK buying some Datum (FTS Division) 1000B
units off me in the 90's. 

http://www.n4iqt.com/fts1000b/1000b-r2.pdf

Nice oscillator.

Rob Kimberley

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Robert Atkinson
Sent: 25 August 2011 5:24 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Racal 9420 OCXO

I'm pretty sure Racal made these. They are of consistent design over
different models and many years and are unlike any other manufacturers OXCO
I've seen. Racal were old school and did prettymuch everything themselves.
The did do what appears to be a licence built Sulzer though. The MA-259, see
http://www.radiomuseum.org/r/racal_precision_frequency_stan.html

Regards,
Robert G8RPI.


--- On Thu, 25/8/11, Bob Camp  wrote:

From: Bob Camp 
Subject: Re: [time-nuts] Racal 9420 OCXO
To: "'Discussion of precise time and frequency measurement'"

Date: Thursday, 25 August, 2011, 17:01

Hi

Do we know for sure that Racal actually made these OCXO's in house?

My *guess* is that they were made by various companies over the years and
sold to Racal. The "return for service" would have been a return to Racal
and then they forward it to the people who made it...

Bob

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of paul swed
Sent: Wednesday, August 24, 2011 5:10 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Racal 9420 OCXO

Kind of amazing what time-nuts have in there secret documentation.
Though I do not need this thanks for sharing.
Regards
Paul
WB8TSL

On Wed, Aug 24, 2011 at 4:05 PM, Robert Atkinson
wrote:

> Hi,
> I've attached a copy of the catalogue specification for Racals OCXOs. 
> They do have electronic trim as standard. They are used in the 9478 
> frequency standard. The 9478 service manual specfically states that no 
> information
on
> the OCXOs is provided and they must be returned to Racal or appointed
agents
> for repair.
>
> Robert G8RPI
>
> --- On Wed, 24/8/11, gandal...@aol.com  wrote:
>
> From: gandal...@aol.com 
> Subject: Re: [time-nuts] Racal 9420 OCXO
> To: time-nuts@febo.com
> Date: Wednesday, 24 August, 2011, 16:03
>
> In a message dated 24/08/2011 00:03:19 GMT Daylight Time, 
> dan...@verizon.net writes:
>
> I don't  think Racal released circuit diagrams of any of their ovens.  
> I have  traced out the circuit of the rapid warm up oven found in a 
> lot of receivers, the 9442-12 and have fixed those, there is a ceramic 
> cap that frequently goes wonky.  The two 9420s I have fixed were just 
> broken wires; they seem to have used PVC insulated wire which 
> degrades...  I haven't done the homework on those yet.
>
> The 9420s I have do have an  EFC input as well as a stabilised Voltage 
> out to feed it, and in the  receivers I have that use it [RA1795] the 
> fine setting is done from that,  coarse setting from the top adjustment.
> -
> Hi Dan
>
> I've taken a further look at the RA1794 manual and see now that it 
> does confirm a fine tune pot being available when using the 9420.
> Having opened up this oscillator I find there are  connections to 
> every
pin
> on the B7G connector so will assume until proven  otherwise that it 
> does meet the interface spec shown in the 1794 manual.
> I suspect the comments I've seen claiming most do not have the EFC  
> option is more a case that in many installations it isn't used, which  
> isn't
quite
> the same thing.
>
> Thanks again for your comments.
>
> regards
>
> Nigel
>
>
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Re: [time-nuts] Active LORAN antenna

[George Dubovsky]

I have the schematic of the active antenna, but I will not be able to get to
it until Monday.

73,

geo - n4ua

On Fri, Aug 26, 2011 at 6:00 AM, Ulrich Bangert wrote:

> Gentlemen,
>
> my friend Frank and I both miss the matching actice antenna for our
> Standford Research FS700 Loran frequency standards. We also do not have a
> schematic of it. Nevertheless we have tried to re-engineer the circut from
> the part's list and the circuit description in the FS700 manual. Our result
> is shown in the accompanying schematic.pdf.
>
> The generator in the left in conjunction with the 10 k resistor represents
> the expected high footpoint impedance of the very short (3 m) antenna. The
> VDD in the right in conjunction with the 100 ohms resistor represents what
> it believed to be inside the FS700.
>
> Not shown here is a 100 k resistor that may be included between the filter
> output and the 7 k resistor to form a 30 dB divider together with it. Also
> not shown is a 390 micro henry inductance which's impact is not to be found
> in the circuit descripion. Also not shown is a small neon bulb for
> overvoltage protection.
>
> The ac analysis shows that the overall filter function is well around 100
> kHz. But it seems as if the fet (a 2N5991 in the original) would not have
> enough gain to counteract the overall damping included in the front end let
> alone to deliver some additional gain for the receiver's front end.
>
> We both feed the receiver currently with dipoles for 80 m ham radio and a
> resistor that makes the receiver think the active antenna is connected. The
> receiver has a possible total of 130 dB gain and my receiver says it uses
> 94
> dB gain while Franks receiver says it uses 102 dB gain. The noise margin is
> also a bit better on my location. However, if one looks at the manual f.e.
> at page 17 one could get the impression as if a receiver gain of 75 dB may
> be considered much more normal as our values. Instead of improving the
> reception everything gets even worse if the active antenna is connected. I
> should also note that my qth is only 200 km away from SYLT (our German
> Loran
> station) while Frank is even 70 km nearer to it.
>
> Questions:
>
> 1) Anyone an idea what we are possibly doing wrong?
>
> 2) Anyone an idea for the 390 micro henry inductor?
>
> 3) Anyone own the original schematic?
>
> TIA for your help
>
> Ulrich Bangert
> www.ulrich-bangert.de
> Ortholzer Weg 1
> 27243 Gross Ippener
>
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> 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.
>
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Re: [time-nuts] Racal 9420 OCXO

[Rob Kimberley]

Hi Robert,

An interesting bit of history there. FTS (Frequency & Time Systems) used to
be owned by Oscilloquartz, but sold to Datum, to get their Caesium products
into the US market, and then FTS licenced the Cs technology back. (I think
I'm right on that one).  Ball Efratom also bought by or merged with Datum.
I used to work for Sematron Limited as Product Manager responsible for all
Datum group products in the UK, and Sematron was set up by to ex-Racal guys
John O'Brien & Kevin Hall.

Rob

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Robert Atkinson
Sent: 26 August 2011 12:49 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Racal 9420 OCXO

Hi Rob,
That's interesting. Racal Instruments were agents for Oscilloquartz and Ball
Efratom. Their Rubidium standards have Efratom FRKs in them.
 
Robert G8RPI.

--- On Thu, 25/8/11, Rob Kimberley  wrote:


From: Rob Kimberley 
Subject: Re: [time-nuts] Racal 9420 OCXO
To: "'Discussion of precise time and frequency measurement'"

Date: Thursday, 25 August, 2011, 22:13


I seem to remember Racal in the UK buying some Datum (FTS Division) 1000B
units off me in the 90's. 

http://www.n4iqt.com/fts1000b/1000b-r2.pdf

Nice oscillator.

Rob Kimberley

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Robert Atkinson
Sent: 25 August 2011 5:24 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Racal 9420 OCXO

I'm pretty sure Racal made these. They are of consistent design over
different models and many years and are unlike any other manufacturers OXCO
I've seen. Racal were old school and did prettymuch everything themselves.
The did do what appears to be a licence built Sulzer though. The MA-259, see
http://www.radiomuseum.org/r/racal_precision_frequency_stan.html

Regards,
Robert G8RPI.


--- On Thu, 25/8/11, Bob Camp  wrote:

From: Bob Camp 
Subject: Re: [time-nuts] Racal 9420 OCXO
To: "'Discussion of precise time and frequency measurement'"

Date: Thursday, 25 August, 2011, 17:01

Hi

Do we know for sure that Racal actually made these OCXO's in house?

My *guess* is that they were made by various companies over the years and
sold to Racal. The "return for service" would have been a return to Racal
and then they forward it to the people who made it...

Bob

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of paul swed
Sent: Wednesday, August 24, 2011 5:10 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Racal 9420 OCXO

Kind of amazing what time-nuts have in there secret documentation.
Though I do not need this thanks for sharing.
Regards
Paul
WB8TSL

On Wed, Aug 24, 2011 at 4:05 PM, Robert Atkinson
wrote:

> Hi,
> I've attached a copy of the catalogue specification for Racals OCXOs. 
> They do have electronic trim as standard. They are used in the 9478 
> frequency standard. The 9478 service manual specfically states that no 
> information
on
> the OCXOs is provided and they must be returned to Racal or appointed
agents
> for repair.
>
> Robert G8RPI
>
> --- On Wed, 24/8/11, gandal...@aol.com  wrote:
>
> From: gandal...@aol.com 
> Subject: Re: [time-nuts] Racal 9420 OCXO
> To: time-nuts@febo.com
> Date: Wednesday, 24 August, 2011, 16:03
>
> In a message dated 24/08/2011 00:03:19 GMT Daylight Time, 
> dan...@verizon.net writes:
>
> I don't  think Racal released circuit diagrams of any of their ovens. 
> I have  traced out the circuit of the rapid warm up oven found in a 
> lot of receivers, the 9442-12 and have fixed those, there is a ceramic 
> cap that frequently goes wonky.  The two 9420s I have fixed were just 
> broken wires; they seem to have used PVC insulated wire which 
> degrades...  I haven't done the homework on those yet.
>
> The 9420s I have do have an  EFC input as well as a stabilised Voltage 
> out to feed it, and in the  receivers I have that use it [RA1795] the 
> fine setting is done from that,  coarse setting from the top adjustment.
> -
> Hi Dan
>
> I've taken a further look at the RA1794 manual and see now that it 
> does confirm a fine tune pot being available when using the 9420.
> Having opened up this oscillator I find there are  connections to 
> every
pin
> on the B7G connector so will assume until proven  otherwise that it 
> does meet the interface spec shown in the 1794 manual.
> I suspect the comments I've seen claiming most do not have the EFC 
> option is more a case that in many installations it isn't used, which 
> isn't
quite
> the same thing.
>
> Thanks again for your comments.
>
> regards
>
> Nigel
>
>
> ___
> 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.
>
> ___

Re: [time-nuts] Active LORAN antenna

[Ulrich Bangert]

Hi George,

I appreciate your help a lot and the next week is surely early enough.

73s de Ulrich, DF6JB

Am 26.08.2011 um 14:15 schrieb George Dubovsky:

> I have the schematic of the active antenna, but I will not be able to get to
> it until Monday.
> 
> 73,
> 
> geo - n4ua
> 
> On Fri, Aug 26, 2011 at 6:00 AM, Ulrich Bangert 
> wrote:
> 
>> Gentlemen,
>> 
>> my friend Frank and I both miss the matching actice antenna for our
>> Standford Research FS700 Loran frequency standards. We also do not have a
>> schematic of it. Nevertheless we have tried to re-engineer the circut from
>> the part's list and the circuit description in the FS700 manual. Our result
>> is shown in the accompanying schematic.pdf.
>> 
>> The generator in the left in conjunction with the 10 k resistor represents
>> the expected high footpoint impedance of the very short (3 m) antenna. The
>> VDD in the right in conjunction with the 100 ohms resistor represents what
>> it believed to be inside the FS700.
>> 
>> Not shown here is a 100 k resistor that may be included between the filter
>> output and the 7 k resistor to form a 30 dB divider together with it. Also
>> not shown is a 390 micro henry inductance which's impact is not to be found
>> in the circuit descripion. Also not shown is a small neon bulb for
>> overvoltage protection.
>> 
>> The ac analysis shows that the overall filter function is well around 100
>> kHz. But it seems as if the fet (a 2N5991 in the original) would not have
>> enough gain to counteract the overall damping included in the front end let
>> alone to deliver some additional gain for the receiver's front end.
>> 
>> We both feed the receiver currently with dipoles for 80 m ham radio and a
>> resistor that makes the receiver think the active antenna is connected. The
>> receiver has a possible total of 130 dB gain and my receiver says it uses
>> 94
>> dB gain while Franks receiver says it uses 102 dB gain. The noise margin is
>> also a bit better on my location. However, if one looks at the manual f.e.
>> at page 17 one could get the impression as if a receiver gain of 75 dB may
>> be considered much more normal as our values. Instead of improving the
>> reception everything gets even worse if the active antenna is connected. I
>> should also note that my qth is only 200 km away from SYLT (our German
>> Loran
>> station) while Frank is even 70 km nearer to it.
>> 
>> Questions:
>> 
>> 1) Anyone an idea what we are possibly doing wrong?
>> 
>> 2) Anyone an idea for the 390 micro henry inductor?
>> 
>> 3) Anyone own the original schematic?
>> 
>> TIA for your help
>> 
>> Ulrich Bangert
>> www.ulrich-bangert.de
>> Ortholzer Weg 1
>> 27243 Gross Ippener
>> 
>> ___
>> 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.
>> 
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> and follow the instructions there.

Ulrich Bangert
Ortholzer Weg1
27243 Gross Ippener
Deutschland
Tel   +49 (0)4224 95071
Fax  +49 (0)4224 95072
Mob +49 (0)172 8006546
www.ulrich-bangert.de



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Re: [time-nuts] Active LORAN antenna

[Stan, W1LE]

Hello UL,

My SRS active antenna is internally potted in resin, so tracing the 
circuit is difficult.


I was able to chip away the PVC white housing and some of the black potting
material to get at the antenna input terminal. Then I repackaged it with 
a new CB antenna.
Living on Cape Cod, quite near to the former Nantucket Loran station, I 
can only rarely receive

some of the European stations.

The schematic in the manual shows a switch or a jumper for the gain 
reduction.
So, the schematic is probably an old version, and "all bets are off" as 
to what

the production models, we have, consist of.

I did buy the manual form SRS and the active antenna schematic shows a 
2N5951,
not the 2N5991 you mention. My schematic is a rev B, Document Number 
FS700-14

This document in not dated.

The frequency selective L-C filter network is different, see attachment.

If the attachment does not get thru, please send your direct e-mail address.


Stan, W1LE Cape CodFN41sr




On 8/26/2011 6:00 AM, Ulrich Bangert wrote:

Gentlemen,

my friend Frank and I both miss the matching actice antenna for our
Standford Research FS700 Loran frequency standards. We also do not have a
schematic of it. Nevertheless we have tried to re-engineer the circut from
the part's list and the circuit description in the FS700 manual. Our result
is shown in the accompanying schematic.pdf.

The generator in the left in conjunction with the 10 k resistor represents
the expected high footpoint impedance of the very short (3 m) antenna. The
VDD in the right in conjunction with the 100 ohms resistor represents what
it believed to be inside the FS700.

Not shown here is a 100 k resistor that may be included between the filter
output and the 7 k resistor to form a 30 dB divider together with it. Also
not shown is a 390 micro henry inductance which's impact is not to be found
in the circuit descripion. Also not shown is a small neon bulb for
overvoltage protection.

The ac analysis shows that the overall filter function is well around 100
kHz. But it seems as if the fet (a 2N5991 in the original) would not have
enough gain to counteract the overall damping included in the front end let
alone to deliver some additional gain for the receiver's front end.

We both feed the receiver currently with dipoles for 80 m ham radio and a
resistor that makes the receiver think the active antenna is connected. The
receiver has a possible total of 130 dB gain and my receiver says it uses 94
dB gain while Franks receiver says it uses 102 dB gain. The noise margin is
also a bit better on my location. However, if one looks at the manual f.e.
at page 17 one could get the impression as if a receiver gain of 75 dB may
be considered much more normal as our values. Instead of improving the
reception everything gets even worse if the active antenna is connected. I
should also note that my qth is only 200 km away from SYLT (our German Loran
station) while Frank is even 70 km nearer to it.

Questions:

1) Anyone an idea what we are possibly doing wrong?

2) Anyone an idea for the 390 micro henry inductor?

3) Anyone own the original schematic?

TIA for your help

Ulrich Bangert
www.ulrich-bangert.de
Ortholzer Weg 1
27243 Gross Ippener


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Re: [time-nuts] Active LORAN antenna

[paul swed]

Stan you beat me to it. This is the schematic I also have.
When LORAN C was active I was at 53 DB using a whip antenna 8' in length.
But I wound 24 guage wire on a 8 ft fiberglass pole hundreds of turns as a
single layer.
This feeds a loran c preamp that used to be common. Nothing magic about it.
The 99600 chain station was 90 miles from my location.
Very clearly the filter on the frontend helps.
Paul
WB8TSL

On Fri, Aug 26, 2011 at 9:02 AM, Stan, W1LE  wrote:

> Hello UL,
>
> My SRS active antenna is internally potted in resin, so tracing the circuit
> is difficult.
>
> I was able to chip away the PVC white housing and some of the black potting
> material to get at the antenna input terminal. Then I repackaged it with a
> new CB antenna.
> Living on Cape Cod, quite near to the former Nantucket Loran station, I can
> only rarely receive
> some of the European stations.
>
> The schematic in the manual shows a switch or a jumper for the gain
> reduction.
> So, the schematic is probably an old version, and "all bets are off" as to
> what
> the production models, we have, consist of.
>
> I did buy the manual form SRS and the active antenna schematic shows a
> 2N5951,
> not the 2N5991 you mention. My schematic is a rev B, Document Number
> FS700-14
> This document in not dated.
>
> The frequency selective L-C filter network is different, see attachment.
>
> If the attachment does not get thru, please send your direct e-mail
> address.
>
>
> Stan, W1LE Cape CodFN41sr
>
>
>
>
>
> On 8/26/2011 6:00 AM, Ulrich Bangert wrote:
>
>> Gentlemen,
>>
>> my friend Frank and I both miss the matching actice antenna for our
>> Standford Research FS700 Loran frequency standards. We also do not have a
>> schematic of it. Nevertheless we have tried to re-engineer the circut from
>> the part's list and the circuit description in the FS700 manual. Our
>> result
>> is shown in the accompanying schematic.pdf.
>>
>> The generator in the left in conjunction with the 10 k resistor represents
>> the expected high footpoint impedance of the very short (3 m) antenna. The
>> VDD in the right in conjunction with the 100 ohms resistor represents what
>> it believed to be inside the FS700.
>>
>> Not shown here is a 100 k resistor that may be included between the filter
>> output and the 7 k resistor to form a 30 dB divider together with it. Also
>> not shown is a 390 micro henry inductance which's impact is not to be
>> found
>> in the circuit descripion. Also not shown is a small neon bulb for
>> overvoltage protection.
>>
>> The ac analysis shows that the overall filter function is well around 100
>> kHz. But it seems as if the fet (a 2N5991 in the original) would not have
>> enough gain to counteract the overall damping included in the front end
>> let
>> alone to deliver some additional gain for the receiver's front end.
>>
>> We both feed the receiver currently with dipoles for 80 m ham radio and a
>> resistor that makes the receiver think the active antenna is connected.
>> The
>> receiver has a possible total of 130 dB gain and my receiver says it uses
>> 94
>> dB gain while Franks receiver says it uses 102 dB gain. The noise margin
>> is
>> also a bit better on my location. However, if one looks at the manual f.e.
>> at page 17 one could get the impression as if a receiver gain of 75 dB may
>> be considered much more normal as our values. Instead of improving the
>> reception everything gets even worse if the active antenna is connected. I
>> should also note that my qth is only 200 km away from SYLT (our German
>> Loran
>> station) while Frank is even 70 km nearer to it.
>>
>> Questions:
>>
>> 1) Anyone an idea what we are possibly doing wrong?
>>
>> 2) Anyone an idea for the 390 micro henry inductor?
>>
>> 3) Anyone own the original schematic?
>>
>> TIA for your help
>>
>> Ulrich Bangert
>> www.ulrich-bangert.de
>> Ortholzer Weg 1
>> 27243 Gross Ippener
>>
>>
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Re: [time-nuts] OT: UK's atomic clock 'is world's most accurate'

[paul swed]

Hmmm would seem that its the same as NIST.
By the way I have one of those in the garage. Or is it that my garage looks
like that?

Will say that the BBC tech info/editorial is quite good as compared to the
watered down stuff we normally see.
Regards
Paul.

On Fri, Aug 26, 2011 at 5:46 AM, David J Taylor <
david-tay...@blueyonder.co.uk> wrote:

> From the BBC: UK's atomic clock 'is world's most accurate', see:
>
>  
> http://www.bbc.co.uk/news/**science-environment-14657002
>
> Cheers,
> David
> --
> SatSignal software - quality software written to your requirements
> Web:  http://www.satsignal.eu
> Email:  david-tay...@blueyonder.co.uk
> __**_
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Re: [time-nuts] OT: UK's atomic clock 'is world's most accurate'

[Rob Kimberley]

Come now, it's British, it's got to be better!

:-)

Rob K

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of paul swed
Sent: 26 August 2011 3:17 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] OT: UK's atomic clock 'is world's most accurate'

Hmmm would seem that its the same as NIST.
By the way I have one of those in the garage. Or is it that my garage looks
like that?

Will say that the BBC tech info/editorial is quite good as compared to the
watered down stuff we normally see.
Regards
Paul.

On Fri, Aug 26, 2011 at 5:46 AM, David J Taylor <
david-tay...@blueyonder.co.uk> wrote:

> From the BBC: UK's atomic clock 'is world's most accurate', see:
>
>  
> http://www.bbc.co.uk/news/**science-environment-14657002 c.co.uk/news/science-environment-14657002>
>
> Cheers,
> David
> --
> SatSignal software - quality software written to your requirements
> Web:  http://www.satsignal.eu
> Email:  david-tay...@blueyonder.co.uk
> __**_
> time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to 
> https://www.febo.com/cgi-bin/** 
> mailman/listinfo/time-nuts fo/time-nuts>
> and follow the instructions there.
>
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Re: [time-nuts] OT: UK's atomic clock 'is world's most accurate'

[Stephen Tompsett]

So now following previous historical precedent,  we should give it to 
the Americans, destroy the original and burn the plans...


On 26/08/2011 15:20, Rob Kimberley wrote:

Come now, it's British, it's got to be better!

:-)

Rob K

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of paul swed
Sent: 26 August 2011 3:17 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] OT: UK's atomic clock 'is world's most accurate'

Hmmm would seem that its the same as NIST.
By the way I have one of those in the garage. Or is it that my garage looks
like that?

Will say that the BBC tech info/editorial is quite good as compared to the
watered down stuff we normally see.
Regards
Paul.

On Fri, Aug 26, 2011 at 5:46 AM, David J Taylor<
david-tay...@blueyonder.co.uk>  wrote:


 From the BBC: UK's atomic clock 'is world's most accurate', see:


http://www.bbc.co.uk/news/**science-environment-14657002

Cheers,
David
--
SatSignal software - quality software written to your requirements
Web:  http://www.satsignal.eu
Email:  david-tay...@blueyonder.co.uk
__**_
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https://www.febo.com/cgi-bin/**
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and follow the instructions there.


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--
Stephen Tompsett



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[time-nuts] OT: UK's atomic clock 'is world's most accurate'

[Mark Sims]

Yeah,  but it leaks oil like a sieve and the blinkenlights go out when it 
rains...


Come now, it's British, it's got to be better!

  
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Re: [time-nuts] OT: UK's atomic clock 'is world's most accurate'

[Rob Kimberley]

Sense of humour - I like it!!


-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Mark Sims
Sent: 26 August 2011 3:40 PM
To: time-nuts@febo.com
Subject: [time-nuts] OT: UK's atomic clock 'is world's most accurate'


Yeah,  but it leaks oil like a sieve and the blinkenlights go out when it
rains...


Come now, it's British, it's got to be better!

  
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Re: [time-nuts] OT: UK's atomic clock 'is world's most accurate'

[Raj]

My son refuses to spend 400$ on steering hydraulics repair but says he'd rather
top up the oil for less than 2$ a month. The car is Japanese!



>Yeah,  but it leaks oil like a sieve and the blinkenlights go out when it 
>rains...
>
>
>Come now, it's British, it's got to be better!


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Re: [time-nuts] Active LORAN antenna

[Brooke Clarke]

Hi Ulrich:

You might consider the AMRAD active antenna that they designed for the 
136 kHz ham band.

http://www.prc68.com/I/LF-Ant.shtml

or the McKay Dymec DA-100 active whip.
http://www.prc68.com/I/DR33.shtml#DA100

Have Fun,

Brooke Clarke
http://www.PRC68.com
http://www.End2PartyGovernment.com/


Ulrich Bangert wrote:

Gentlemen,

my friend Frank and I both miss the matching actice antenna for our
Standford Research FS700 Loran frequency standards. We also do not have a
schematic of it. Nevertheless we have tried to re-engineer the circut from
the part's list and the circuit description in the FS700 manual. Our result
is shown in the accompanying schematic.pdf.

The generator in the left in conjunction with the 10 k resistor represents
the expected high footpoint impedance of the very short (3 m) antenna. The
VDD in the right in conjunction with the 100 ohms resistor represents what
it believed to be inside the FS700.

Not shown here is a 100 k resistor that may be included between the filter
output and the 7 k resistor to form a 30 dB divider together with it. Also
not shown is a 390 micro henry inductance which's impact is not to be found
in the circuit descripion. Also not shown is a small neon bulb for
overvoltage protection.

The ac analysis shows that the overall filter function is well around 100
kHz. But it seems as if the fet (a 2N5991 in the original) would not have
enough gain to counteract the overall damping included in the front end let
alone to deliver some additional gain for the receiver's front end.

We both feed the receiver currently with dipoles for 80 m ham radio and a
resistor that makes the receiver think the active antenna is connected. The
receiver has a possible total of 130 dB gain and my receiver says it uses 94
dB gain while Franks receiver says it uses 102 dB gain. The noise margin is
also a bit better on my location. However, if one looks at the manual f.e.
at page 17 one could get the impression as if a receiver gain of 75 dB may
be considered much more normal as our values. Instead of improving the
reception everything gets even worse if the active antenna is connected. I
should also note that my qth is only 200 km away from SYLT (our German Loran
station) while Frank is even 70 km nearer to it.

Questions:

1) Anyone an idea what we are possibly doing wrong?

2) Anyone an idea for the 390 micro henry inductor?

3) Anyone own the original schematic?

TIA for your help

Ulrich Bangert
www.ulrich-bangert.de
Ortholzer Weg 1
27243 Gross Ippener
   



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Re: [time-nuts] OT: UK's atomic clock 'is world's most accurate'

[J. Forster]

If only you knew!

-John


>
> Yeah,  but it leaks oil like a sieve and the blinkenlights go out when it
> rains...
>
> 
> Come now, it's British, it's got to be better!
>
>
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Re: [time-nuts] OT: UK's atomic clock 'is world's most accurate'

[Javier Herrero]

It also appears in the spanish press: 
http://www.abc.es/20110826/ciencia/abci-reloj-preciso-mundo-201108261209.html


Regards,

Javier

El 26/08/2011 16:20, Rob Kimberley escribió:

Come now, it's British, it's got to be better!

:-)

Rob K

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of paul swed
Sent: 26 August 2011 3:17 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] OT: UK's atomic clock 'is world's most accurate'

Hmmm would seem that its the same as NIST.
By the way I have one of those in the garage. Or is it that my garage looks
like that?

Will say that the BBC tech info/editorial is quite good as compared to the
watered down stuff we normally see.
Regards
Paul.

On Fri, Aug 26, 2011 at 5:46 AM, David J Taylor<
david-tay...@blueyonder.co.uk>  wrote:


 From the BBC: UK's atomic clock 'is world's most accurate', see:


http://www.bbc.co.uk/news/**science-environment-14657002<http://www.bb
c.co.uk/news/science-environment-14657002>

Cheers,
David
--
SatSignal software - quality software written to your requirements
Web:  http://www.satsignal.eu
Email:  david-tay...@blueyonder.co.uk
__**_
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Re: [time-nuts] Austron GPS antennas

[k4...@aol.com]

Paul, I think the original thread was for a downconverter for the Austron  
and others that use 75.42 MHz as the IF.  However, I need 35.42 MHz for the  
Odetics unit.  Regards, Doug.


Connected by DROID on Verizon Wireless

-Original message-
From: paul swed 
To: Discussion of precise time and frequency measurement  


Sent: Fri, Aug 26, 2011 02:04:17 GMT+00:00
Subject: Re: [time-nuts] Austron GPS antennas

Good to hear.
But I do not see superstar rcvrs around anymore.
I thought the thread was on building up a converter?
Must have lost the direction at some point.
Regards


On Thu, Aug 25, 2011 at 7:35 PM, k4...@aol.com  wrote:


Hi Paul,
I am looking into using one of my SuperStar GPS receivers for this.  I'll
just tap into the circuit at the 35.42 MHz filter.  I just need to build  

up
an amplifier for some addional level contol plus providing isolation for  

the

SuperStar.  I am going to use the 10 MHz TCXO that's on the receiver to
start, then if that much works OK I'll use the 10 MHz signal from the
Odetics unit.  I'll keep you informed on my progress.  73, Doug, K4cle.


Connected by DROID on Verizon Wireless

-Original message-
From: paul swed 
To: Discussion of precise time and frequency measurement <
time-nuts@febo.com>
Sent: Thu, Aug 25, 2011 15:47:59 GMT+00:00
Subject: Re: [time-nuts] Austron GPS antennas

Thread died off is it still going?


On Thu, Aug 18, 2011 at 6:32 PM, Magnus Danielson <
mag...@rubidium.dyndns.org> wrote:

 On 18/08/11 23:49, k4...@aol.com wrote:


 Hi Magnus, thanks for that information.  I had forgotten about that

Plessey GP2010 and GP2015 RF chip. The only problem is that you have to
do a divide by 7 on the 40 MHz signal that Plessey did in the GP2021
correlator IC. Using an old SuperStar RX is a good reconmendation.
Thanks. Doug, k4cle.



There is a whole little line of GPS receivers of the same chips.

Hacking in external clock onto a SuperStar isn't all that hard.

You will not have to do the divide by 7 in this case, For this  

application
you get 35,42 MHz out in the second filter stage, just tap in on that  

with




a


diffrential pair after the filter and you are essentially done. In the
GP2010/2015 topology it goes back in for AGC and sampler action. If your
receiver expects the 35,42 MHz signal, it gets inserted into that place


from


a receiver buffer with filter and then the rest of the analog and digital
path is continued... that's how they use up two GP2010/2015 chips, but  

can

get away with longer cable runs since the damping of 35,42 MHz is much


less


than that of 1575,42 MHz in RG-58


Cheers,
Magnus

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Re: [time-nuts] Active LORAN antenna

[Poul-Henning Kamp]

In message <4e57cbee.3000...@pacific.net>, Brooke Clarke writes:

>You might consider the AMRAD active antenna that they designed for the 
>136 kHz ham band.

If you want to build an active monopole, Chris Trasks "secret" design
is far better and far more manageable than the AMRAD:

http://www.home.earthlink.net/~christrask/Paper007.html

I built this one with BFQ19+BQ149+J174+J310 all in SMD parts.

(J270 is a better choice than J174 which tends to forward bias)

With my primitive measurement methods, it was flat to 100 MHz
and tapered off just short of 800MHz.

In the other end it reliably pulls out the Russian ELF (OMEGA like)
navigation system down around 10kHz.

Chris mentioned that a kit might be underway, but I havn't seen
any sign of it anywhere...

-- 
Poul-Henning Kamp   | UNIX since Zilog Zeus 3.20
p...@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.

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Re: [time-nuts] Active LORAN antenna

[k4...@aol.com]

Hey Brooke, 
How are you doing?  Are you still using that AMRAD antenna preamp I made for  
you several years ago?  It's been several years since we emailed each other  
and I have lost contact with you until now.  Last time I heard from you,  
your wife had run over the coax with the lawn mower and cut it into!  Just  
curious if that thing was still working.  73's.  Doug, k4cle.


Connected by DROID on Verizon Wireless

-Original message-
From: Brooke Clarke 
To: Discussion of precise time and frequency measurement  


Sent: Fri, Aug 26, 2011 16:39:01 GMT+00:00
Subject: Re: [time-nuts] Active LORAN antenna

Hi Ulrich:

You might consider the AMRAD active antenna that they designed for the 
136 kHz ham band.

http://www.prc68.com/I/LF-Ant.shtml

or the McKay Dymec DA-100 active whip.
http://www.prc68.com/I/DR33.shtml#DA100

Have Fun,

Brooke Clarke
http://www.PRC68.com
http://www.End2PartyGovernment.com/


Ulrich Bangert wrote:

Gentlemen,

my friend Frank and I both miss the matching actice antenna for our
Standford Research FS700 Loran frequency standards. We also do not have a
schematic of it. Nevertheless we have tried to re-engineer the circut from
the part's list and the circuit description in the FS700 manual. Our  

result

is shown in the accompanying schematic.pdf.

The generator in the left in conjunction with the 10 k resistor represents
the expected high footpoint impedance of the very short (3 m) antenna. The
VDD in the right in conjunction with the 100 ohms resistor represents what
it believed to be inside the FS700.

Not shown here is a 100 k resistor that may be included between the filter
output and the 7 k resistor to form a 30 dB divider together with it. Also
not shown is a 390 micro henry inductance which's impact is not to be  

found

in the circuit descripion. Also not shown is a small neon bulb for
overvoltage protection.

The ac analysis shows that the overall filter function is well around 100
kHz. But it seems as if the fet (a 2N5991 in the original) would not have
enough gain to counteract the overall damping included in the front end  

let

alone to deliver some additional gain for the receiver's front end.

We both feed the receiver currently with dipoles for 80 m ham radio and a
resistor that makes the receiver think the active antenna is connected.  

The
receiver has a possible total of 130 dB gain and my receiver says it uses  

94
dB gain while Franks receiver says it uses 102 dB gain. The noise margin  

is

also a bit better on my location. However, if one looks at the manual f.e.
at page 17 one could get the impression as if a receiver gain of 75 dB may
be considered much more normal as our values. Instead of improving the
reception everything gets even worse if the active antenna is connected. I
should also note that my qth is only 200 km away from SYLT (our German  

Loran

station) while Frank is even 70 km nearer to it.

Questions:

1) Anyone an idea what we are possibly doing wrong?

2) Anyone an idea for the 390 micro henry inductor?

3) Anyone own the original schematic?

TIA for your help

Ulrich Bangert
www.ulrich-bangert.de
Ortholzer Weg 1
27243 Gross Ippener
   



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Re: [time-nuts] Active LORAN antenna

[Brooke Clarke]

Hi Doug:

It turns out that the fuses AMRAD specified were way too high in current 
to keep the transformer from being smoked.  The only fuses that work are 
self resetting types.  I've added them on  the primary and secondary 
side of the transformer but have not yet reinstalled the antenna.  I get 
requests every now and then for someone to build that AMRAD antenna.  
Are you still making them?


Just sent an email to Chris Trask asking about his push pull design.

My interest in active antennas is for the low frequency area where 
quarter wave wire antennas are not practical.
For HF you can't beat wire antennas.  Active antennas, either whip or 
loop do not work as well as wire.

http://www.prc68.com/I/WireAntenna.shtml

Have Fun,

Brooke Clarke
http://www.PRC68.com
http://www.End2PartyGovernment.com/


k4...@aol.com wrote:
Hey Brooke,How are you doing?  Are you still using that AMRAD antenna 
preamp I made for you several years ago?  It's been several years 
since we emailed each other and I have lost contact with you until 
now.  Last time I heard from you, your wife had run over the coax with 
the lawn mower and cut it into!  Just curious if that thing was still 
working.  73's.  Doug, k4cle.


Connected by DROID on Verizon Wireless

-Original message-
From: Brooke Clarke 
To: Discussion of precise time and frequency measurement 


Sent: Fri, Aug 26, 2011 16:39:01 GMT+00:00
Subject: Re: [time-nuts] Active LORAN antenna

Hi Ulrich:

You might consider the AMRAD active antenna that they designed for 
the136 kHz ham band.

http://www.prc68.com/I/LF-Ant.shtml

or the McKay Dymec DA-100 active whip.
http://www.prc68.com/I/DR33.shtml#DA100

Have Fun,

Brooke Clarke
http://www.PRC68.com
http://www.End2PartyGovernment.com/


Ulrich Bangert wrote:

Gentlemen,

my friend Frank and I both miss the matching actice antenna for our
Standford Research FS700 Loran frequency standards. We also do not 
have a
schematic of it. Nevertheless we have tried to re-engineer the circut 
from
the part's list and the circuit description in the FS700 manual. Our 

result

is shown in the accompanying schematic.pdf.

The generator in the left in conjunction with the 10 k resistor 
represents
the expected high footpoint impedance of the very short (3 m) 
antenna. The
VDD in the right in conjunction with the 100 ohms resistor represents 
what

it believed to be inside the FS700.

Not shown here is a 100 k resistor that may be included between the 
filter
output and the 7 k resistor to form a 30 dB divider together with it. 
Also
not shown is a 390 micro henry inductance which's impact is not to be 

found

in the circuit descripion. Also not shown is a small neon bulb for
overvoltage protection.

The ac analysis shows that the overall filter function is well around 
100
kHz. But it seems as if the fet (a 2N5991 in the original) would not 
have
enough gain to counteract the overall damping included in the front end 

let

alone to deliver some additional gain for the receiver's front end.

We both feed the receiver currently with dipoles for 80 m ham radio 
and a
resistor that makes the receiver think the active antenna is connected. 

The
receiver has a possible total of 130 dB gain and my receiver says it 
uses 

94
dB gain while Franks receiver says it uses 102 dB gain. The noise margin 

is
also a bit better on my location. However, if one looks at the manual 
f.e.
at page 17 one could get the impression as if a receiver gain of 75 
dB may

be considered much more normal as our values. Instead of improving the
reception everything gets even worse if the active antenna is 
connected. I
should also note that my qth is only 200 km away from SYLT (our German 

Loran

station) while Frank is even 70 km nearer to it.

Questions:

1) Anyone an idea what we are possibly doing wrong?

2) Anyone an idea for the 390 micro henry inductor?

3) Anyone own the original schematic?

TIA for your help

Ulrich Bangert
www.ulrich-bangert.de
Ortholzer Weg 1
27243 Gross Ippener


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Re: [time-nuts] Active LORAN antenna

[Poul-Henning Kamp]

In message <4e5803cd.5020...@pacific.net>, Brooke Clarke writes:

>My interest in active antennas is for the low frequency area where 
>quarter wave wire antennas are not practical.

That's why I built it:  Loran-C, DCF77, Rugby and HBG.

>For HF you can't beat wire antennas.  Active antennas, either whip or 
>loop do not work as well as wire.

Well, strictly specking he same is true for low frequency, there are
terms in Maxwells equations which means that size matter.

Poul-henning

PS: Danish blog-post w/ pictures of my build of Chris Trasks antenna:

http://ing.dk/artikel/96239-min-stakkels-revisor


-- 
Poul-Henning Kamp   | UNIX since Zilog Zeus 3.20
p...@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.

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Re: [time-nuts] Active LORAN antenna

[Bob Camp]

Hi

ESD is also an issue with outdoor active antennas. Even if you don't get a
lightning hit, anything sticking up into the air can get a pretty good
charge on it as the clouds go over. The blocking cap on the input to the
Trask amp really isn't needed with a monopole. It's also unlikely to survive
the summer. The real question is weather if fails open or as a short...

Bob

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Brooke Clarke
Sent: Friday, August 26, 2011 4:36 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Active LORAN antenna

Hi Doug:

It turns out that the fuses AMRAD specified were way too high in current 
to keep the transformer from being smoked.  The only fuses that work are 
self resetting types.  I've added them on  the primary and secondary 
side of the transformer but have not yet reinstalled the antenna.  I get 
requests every now and then for someone to build that AMRAD antenna.  
Are you still making them?

Just sent an email to Chris Trask asking about his push pull design.

My interest in active antennas is for the low frequency area where 
quarter wave wire antennas are not practical.
For HF you can't beat wire antennas.  Active antennas, either whip or 
loop do not work as well as wire.
http://www.prc68.com/I/WireAntenna.shtml

Have Fun,

Brooke Clarke
http://www.PRC68.com
http://www.End2PartyGovernment.com/


k4...@aol.com wrote:
> Hey Brooke,How are you doing?  Are you still using that AMRAD antenna 
> preamp I made for you several years ago?  It's been several years 
> since we emailed each other and I have lost contact with you until 
> now.  Last time I heard from you, your wife had run over the coax with 
> the lawn mower and cut it into!  Just curious if that thing was still 
> working.  73's.  Doug, k4cle.
>
> Connected by DROID on Verizon Wireless
>
> -Original message-
> From: Brooke Clarke 
> To: Discussion of precise time and frequency measurement 
> 
> Sent: Fri, Aug 26, 2011 16:39:01 GMT+00:00
> Subject: Re: [time-nuts] Active LORAN antenna
>
> Hi Ulrich:
>
> You might consider the AMRAD active antenna that they designed for 
> the136 kHz ham band.
> http://www.prc68.com/I/LF-Ant.shtml
>
> or the McKay Dymec DA-100 active whip.
> http://www.prc68.com/I/DR33.shtml#DA100
>
> Have Fun,
>
> Brooke Clarke
> http://www.PRC68.com
> http://www.End2PartyGovernment.com/
>
>
> Ulrich Bangert wrote:
>> Gentlemen,
>>
>> my friend Frank and I both miss the matching actice antenna for our
>> Standford Research FS700 Loran frequency standards. We also do not 
>> have a
>> schematic of it. Nevertheless we have tried to re-engineer the circut 
>> from
>> the part's list and the circuit description in the FS700 manual. Our 
> result
>> is shown in the accompanying schematic.pdf.
>>
>> The generator in the left in conjunction with the 10 k resistor 
>> represents
>> the expected high footpoint impedance of the very short (3 m) 
>> antenna. The
>> VDD in the right in conjunction with the 100 ohms resistor represents 
>> what
>> it believed to be inside the FS700.
>>
>> Not shown here is a 100 k resistor that may be included between the 
>> filter
>> output and the 7 k resistor to form a 30 dB divider together with it. 
>> Also
>> not shown is a 390 micro henry inductance which's impact is not to be 
> found
>> in the circuit descripion. Also not shown is a small neon bulb for
>> overvoltage protection.
>>
>> The ac analysis shows that the overall filter function is well around 
>> 100
>> kHz. But it seems as if the fet (a 2N5991 in the original) would not 
>> have
>> enough gain to counteract the overall damping included in the front end 
> let
>> alone to deliver some additional gain for the receiver's front end.
>>
>> We both feed the receiver currently with dipoles for 80 m ham radio 
>> and a
>> resistor that makes the receiver think the active antenna is connected. 
> The
>> receiver has a possible total of 130 dB gain and my receiver says it 
>> uses 
> 94
>> dB gain while Franks receiver says it uses 102 dB gain. The noise margin 
> is
>> also a bit better on my location. However, if one looks at the manual 
>> f.e.
>> at page 17 one could get the impression as if a receiver gain of 75 
>> dB may
>> be considered much more normal as our values. Instead of improving the
>> reception everything gets even worse if the active antenna is 
>> connected. I
>> should also note that my qth is only 200 km away from SYLT (our German 
> Loran
>> station) while Frank is even 70 km nearer to it.
>>
>> Questions:
>>
>> 1) Anyone an idea what we are possibly doing wrong?
>>
>> 2) Anyone an idea for the 390 micro henry inductor?
>>
>> 3) Anyone own the original schematic?
>>
>> TIA for your help
>>
>> Ulrich Bangert
>> www.ulrich-bangert.de
>> Ortholzer Weg 1
>> 27243 Gross Ippener
>>
>>
>> ___
>> time-nuts mailing list -- time-nuts@febo.com
>> To

Re: [time-nuts] Active LORAN antenna

[Brooke Clarke]

Hi Poul:

It looks like the noise floor is maybe 10 dB higher than the AMRAD
http://www.prc68.com/I/Images/AMRAD_BT.GIF

or 30 dB higher than the McKay Dymec active antenna.
http://www.prc68.com/I/Images/Da100nf.GIF

Have Fun,

Brooke Clarke
http://www.PRC68.com
http://www.End2PartyGovernment.com/


Poul-Henning Kamp wrote:

In message<4e5803cd.5020...@pacific.net>, Brooke Clarke writes:

   

My interest in active antennas is for the low frequency area where
quarter wave wire antennas are not practical.
 

That's why I built it:  Loran-C, DCF77, Rugby and HBG.

   

For HF you can't beat wire antennas.  Active antennas, either whip or
loop do not work as well as wire.
 

Well, strictly specking he same is true for low frequency, there are
terms in Maxwells equations which means that size matter.

Poul-henning

PS: Danish blog-post w/ pictures of my build of Chris Trasks antenna:

http://ing.dk/artikel/96239-min-stakkels-revisor


   


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Re: [time-nuts] Active LORAN antenna

[Brooke Clarke]

Hi Bob:

My problem was the lawnmower cutting the coax between the antenna and 
it's DC power supply.  The short on the output of the DC supply blew the 
very special transformer.


Have Fun,

Brooke Clarke
http://www.PRC68.com
http://www.End2PartyGovernment.com/


Bob Camp wrote:

Hi

ESD is also an issue with outdoor active antennas. Even if you don't get a
lightning hit, anything sticking up into the air can get a pretty good
charge on it as the clouds go over. The blocking cap on the input to the
Trask amp really isn't needed with a monopole. It's also unlikely to survive
the summer. The real question is weather if fails open or as a short...

Bob

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Brooke Clarke
Sent: Friday, August 26, 2011 4:36 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Active LORAN antenna

Hi Doug:

It turns out that the fuses AMRAD specified were way too high in current
to keep the transformer from being smoked.  The only fuses that work are
self resetting types.  I've added them on  the primary and secondary
side of the transformer but have not yet reinstalled the antenna.  I get
requests every now and then for someone to build that AMRAD antenna.
Are you still making them?

Just sent an email to Chris Trask asking about his push pull design.

My interest in active antennas is for the low frequency area where
quarter wave wire antennas are not practical.
For HF you can't beat wire antennas.  Active antennas, either whip or
loop do not work as well as wire.
http://www.prc68.com/I/WireAntenna.shtml

Have Fun,

Brooke Clarke
http://www.PRC68.com
http://www.End2PartyGovernment.com/


k4...@aol.com wrote:
   

Hey Brooke,How are you doing?  Are you still using that AMRAD antenna
preamp I made for you several years ago?  It's been several years
since we emailed each other and I have lost contact with you until
now.  Last time I heard from you, your wife had run over the coax with
the lawn mower and cut it into!  Just curious if that thing was still
working.  73's.  Doug, k4cle.

Connected by DROID on Verizon Wireless

-Original message-
From: Brooke Clarke
To: Discussion of precise time and frequency measurement

Sent: Fri, Aug 26, 2011 16:39:01 GMT+00:00
Subject: Re: [time-nuts] Active LORAN antenna

Hi Ulrich:

You might consider the AMRAD active antenna that they designed for
the136 kHz ham band.
http://www.prc68.com/I/LF-Ant.shtml

or the McKay Dymec DA-100 active whip.
http://www.prc68.com/I/DR33.shtml#DA100

Have Fun,

Brooke Clarke
http://www.PRC68.com
http://www.End2PartyGovernment.com/


Ulrich Bangert wrote:
 

Gentlemen,

my friend Frank and I both miss the matching actice antenna for our
Standford Research FS700 Loran frequency standards. We also do not
have a
schematic of it. Nevertheless we have tried to re-engineer the circut
from
the part's list and the circuit description in the FS700 manual. Our
   

result
 

is shown in the accompanying schematic.pdf.

The generator in the left in conjunction with the 10 k resistor
represents
the expected high footpoint impedance of the very short (3 m)
antenna. The
VDD in the right in conjunction with the 100 ohms resistor represents
what
it believed to be inside the FS700.

Not shown here is a 100 k resistor that may be included between the
filter
output and the 7 k resistor to form a 30 dB divider together with it.
Also
not shown is a 390 micro henry inductance which's impact is not to be
   

found
 

in the circuit descripion. Also not shown is a small neon bulb for
overvoltage protection.

The ac analysis shows that the overall filter function is well around
100
kHz. But it seems as if the fet (a 2N5991 in the original) would not
have
enough gain to counteract the overall damping included in the front end
   

let
 

alone to deliver some additional gain for the receiver's front end.

We both feed the receiver currently with dipoles for 80 m ham radio
and a
resistor that makes the receiver think the active antenna is connected.
   

The
 

receiver has a possible total of 130 dB gain and my receiver says it
uses
   

94
 

dB gain while Franks receiver says it uses 102 dB gain. The noise margin
   

is
 

also a bit better on my location. However, if one looks at the manual
f.e.
at page 17 one could get the impression as if a receiver gain of 75
dB may
be considered much more normal as our values. Instead of improving the
reception everything gets even worse if the active antenna is
connected. I
should also note that my qth is only 200 km away from SYLT (our German
   

Loran
 

station) while Frank is even 70 km nearer to it.

Questions:

1) Anyone an idea what we are possibly doing wrong?

2) Anyone an idea for the 390 micro henry inductor?

3) Anyone own the original schematic?

TIA for your help

Ulrich Bangert
www.ulrich-bangert.de
Ortholzer Weg 1
27243 Gr

Re: [time-nuts] Active LORAN antenna

[Poul-Henning Kamp]

In message , "Bob Camp" writes:

>The blocking cap on the input to the Trask amp really isn't needed
>with a monopole. It's also unlikely to survive
>the summer. The real question is weather if fails open or as a short...

I put mine up two years ago, and it still works fine...

-- 
Poul-Henning Kamp   | UNIX since Zilog Zeus 3.20
p...@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.

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Re: [time-nuts] Active LORAN antenna

[Poul-Henning Kamp]

In message <4e580972.6080...@pacific.net>, Brooke Clarke writes:

>It looks like the noise floor is maybe 10 dB higher than the AMRAD
>http://www.prc68.com/I/Images/AMRAD_BT.GIF
>
>or 30 dB higher than the McKay Dymec active antenna.
>http://www.prc68.com/I/Images/Da100nf.GIF

If you are basing that claim on the SA plot in my blog-post, you
instantly win the "inappropriate apple-oranges comparison price of
the year"

First there is nothing even remotely close to a natural noise-floor
in the LW broadcast band in the middle of a city here in Denmark,
there is far too much EMI from switchmodes etc etc.

Second, there is a significant impedance mismatch between the antenna
and my SA in that plot.   I backhaul the signal over a balanced
twinax cable (78Z I belive) and crank it up for the LORAN-C receiver
in the matching balun, so the feed impedance is way higher than 50Z

Mind you, I don't dispute that you may be right, I just don't think
you have data to back up your claim...


-- 
Poul-Henning Kamp   | UNIX since Zilog Zeus 3.20
p...@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.

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Re: [time-nuts] 5370B Reference Output (was: 5370B airflow)

[Heinzmann, Stefan (ALC NetworX GmbH)]

I got some more niggles regarding my 5370B after the sidepanel question (btw, 
thanks for your answers!):

I have a spray of harmonics from the reference output. On this list it seemed 
to be agreed upon that the source was the 10MHz presence detection circuit, and 
the easy remedy would be disabling it, which only affects a useless service LED.

The problem is, that it didn't work for me. I disabled the circuit, and I still 
have harmonics. The source is a sharp kink in the sine waveform of the signal, 
and I suspect some sort of ground bounce or crosstalk is responsible for it, 
since it coincides with a square wave edge on the reference driver board.

I try to attach a scope snaphot and a spectrum. I hope you will be able to see 
it.

>From past discussions I conclude that I should be getting a relatively clean 
>signal after disabling the detector circuit on A8, so would you agree that 
>something is amiss? The counter works ok and doesn't show excessive jitter, 
>but I'd rather have a cleaner reference signal for other uses...

Cheers
Stefan
<>

5370B Ref Out.plt
Description: 5370B Ref Out.plt
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Re: [time-nuts] Active LORAN antenna

[Brooke Clarke]

Hi Poul:

You're correct.
The noise floor for the AMRAD unit is caused by line conducted noise, 
not the background noise coming from the whip.
The DA-100 seems to have filtered out the line noise so you do see the 
background.

I live in a jungle (forrest?) so there's not as much noise as in a city.

Have Fun,

Brooke Clarke
http://www.PRC68.com
http://www.End2PartyGovernment.com/


Poul-Henning Kamp wrote:

In message<4e580972.6080...@pacific.net>, Brooke Clarke writes:

   

It looks like the noise floor is maybe 10 dB higher than the AMRAD
http://www.prc68.com/I/Images/AMRAD_BT.GIF

or 30 dB higher than the McKay Dymec active antenna.
http://www.prc68.com/I/Images/Da100nf.GIF
 

If you are basing that claim on the SA plot in my blog-post, you
instantly win the "inappropriate apple-oranges comparison price of
the year"

First there is nothing even remotely close to a natural noise-floor
in the LW broadcast band in the middle of a city here in Denmark,
there is far too much EMI from switchmodes etc etc.

Second, there is a significant impedance mismatch between the antenna
and my SA in that plot.   I backhaul the signal over a balanced
twinax cable (78Z I belive) and crank it up for the LORAN-C receiver
in the matching balun, so the feed impedance is way higher than 50Z

Mind you, I don't dispute that you may be right, I just don't think
you have data to back up your claim...


   


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Re: [time-nuts] Active LORAN antenna

[Chuck Forsberg WA7KGX N2469R]

Try to get a DA-100 with a socket for the FET along with some spare FETs.
The FETs are very hard to get but a sub will work if strong local 
signals are absent.


On 08/26/2011 02:46 PM, Brooke Clarke wrote:

Hi Poul:

You're correct.
The noise floor for the AMRAD unit is caused by line conducted noise, 
not the background noise coming from the whip.
The DA-100 seems to have filtered out the line noise so you do see the 
background.

I live in a jungle (forrest?) so there's not as much noise as in a city.

Have Fun,

Brooke Clarke
http://www.PRC68.com
http://www.End2PartyGovernment.com/


Poul-Henning Kamp wrote:

In message<4e580972.6080...@pacific.net>, Brooke Clarke writes:


It looks like the noise floor is maybe 10 dB higher than the AMRAD
http://www.prc68.com/I/Images/AMRAD_BT.GIF

or 30 dB higher than the McKay Dymec active antenna.
http://www.prc68.com/I/Images/Da100nf.GIF

If you are basing that claim on the SA plot in my blog-post, you
instantly win the "inappropriate apple-oranges comparison price of
the year"

First there is nothing even remotely close to a natural noise-floor
in the LW broadcast band in the middle of a city here in Denmark,
there is far too much EMI from switchmodes etc etc.

Second, there is a significant impedance mismatch between the antenna
and my SA in that plot.   I backhaul the signal over a balanced
twinax cable (78Z I belive) and crank it up for the LORAN-C receiver
in the matching balun, so the feed impedance is way higher than 50Z

Mind you, I don't dispute that you may be right, I just don't think
you have data to back up your claim...




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--
Chuck Forsberg WA7KGX N2469R c...@omen.com   www.omen.com
Developer of Industrial ZMODEM(Tm) for Embedded Applications
  Omen Technology Inc  "The High Reliability Software"
10255 NW Old Cornelius Pass Portland OR 97231   503-614-0430


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Re: [time-nuts] Active LORAN antenna

[k4...@aol.com]

Brooke, no I am not making the AMRAD units any longer.  I made several of  
them for various folks, but had to stop making them due to some health  
issues I had a few years ago.  73's, Doug...


Connected by DROID on Verizon Wireless

-Original message-
From: Brooke Clarke 
To: Discussion of precise time and frequency measurement  


Sent: Fri, Aug 26, 2011 20:37:43 GMT+00:00
Subject: Re: [time-nuts] Active LORAN antenna

Hi Doug:

It turns out that the fuses AMRAD specified were way too high in current 
to keep the transformer from being smoked.  The only fuses that work are 
self resetting types.  I've added them on  the primary and secondary 
side of the transformer but have not yet reinstalled the antenna.  I get 
requests every now and then for someone to build that AMRAD antenna.  
Are you still making them?


Just sent an email to Chris Trask asking about his push pull design.

My interest in active antennas is for the low frequency area where 
quarter wave wire antennas are not practical.
For HF you can't beat wire antennas.  Active antennas, either whip or 
loop do not work as well as wire.

http://www.prc68.com/I/WireAntenna.shtml

Have Fun,

Brooke Clarke
http://www.PRC68.com
http://www.End2PartyGovernment.com/


k4...@aol.com wrote:
Hey Brooke,How are you doing?  Are you still using that AMRAD antenna 
preamp I made for you several years ago?  It's been several years 
since we emailed each other and I have lost contact with you until 
now.  Last time I heard from you, your wife had run over the coax with 
the lawn mower and cut it into!  Just curious if that thing was still 
working.  73's.  Doug, k4cle.


Connected by DROID on Verizon Wireless

-Original message-
From: Brooke Clarke 
To: Discussion of precise time and frequency measurement 


Sent: Fri, Aug 26, 2011 16:39:01 GMT+00:00
Subject: Re: [time-nuts] Active LORAN antenna

Hi Ulrich:

You might consider the AMRAD active antenna that they designed for 
the136 kHz ham band.

http://www.prc68.com/I/LF-Ant.shtml

or the McKay Dymec DA-100 active whip.
http://www.prc68.com/I/DR33.shtml#DA100

Have Fun,

Brooke Clarke
http://www.PRC68.com
http://www.End2PartyGovernment.com/


Ulrich Bangert wrote:

Gentlemen,

my friend Frank and I both miss the matching actice antenna for our
Standford Research FS700 Loran frequency standards. We also do not 
have a
schematic of it. Nevertheless we have tried to re-engineer the circut 
from
the part's list and the circuit description in the FS700 manual. Our 

result

is shown in the accompanying schematic.pdf.

The generator in the left in conjunction with the 10 k resistor 
represents
the expected high footpoint impedance of the very short (3 m) 
antenna. The
VDD in the right in conjunction with the 100 ohms resistor represents 
what

it believed to be inside the FS700.

Not shown here is a 100 k resistor that may be included between the 
filter
output and the 7 k resistor to form a 30 dB divider together with it. 
Also
not shown is a 390 micro henry inductance which's impact is not to be 

found

in the circuit descripion. Also not shown is a small neon bulb for
overvoltage protection.

The ac analysis shows that the overall filter function is well around 
100
kHz. But it seems as if the fet (a 2N5991 in the original) would not 
have
enough gain to counteract the overall damping included in the front end 

let

alone to deliver some additional gain for the receiver's front end.

We both feed the receiver currently with dipoles for 80 m ham radio 
and a
resistor that makes the receiver think the active antenna is connected. 

The
receiver has a possible total of 130 dB gain and my receiver says it 
uses 

94
dB gain while Franks receiver says it uses 102 dB gain. The noise margin 

is
also a bit better on my location. However, if one looks at the manual 
f.e.
at page 17 one could get the impression as if a receiver gain of 75 
dB may

be considered much more normal as our values. Instead of improving the
reception everything gets even worse if the active antenna is 
connected. I
should also note that my qth is only 200 km away from SYLT (our German 

Loran

station) while Frank is even 70 km nearer to it.

Questions:

1) Anyone an idea what we are possibly doing wrong?

2) Anyone an idea for the 390 micro henry inductor?

3) Anyone own the original schematic?

TIA for your help

Ulrich Bangert
www.ulrich-bangert.de
Ortholzer Weg 1
27243 Gross Ippener


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Re: [time-nuts] Active LORAN antenna

[paul swed]

Thanks for the link. Just ordered parts.
Talk about cheap! Mouser electronics had all of the TO92 parts.
Regards
Paul.

On Fri, Aug 26, 2011 at 3:27 PM, Poul-Henning Kamp wrote:

> In message <4e57cbee.3000...@pacific.net>, Brooke Clarke writes:
>
> >You might consider the AMRAD active antenna that they designed for the
> >136 kHz ham band.
>
> If you want to build an active monopole, Chris Trasks "secret" design
> is far better and far more manageable than the AMRAD:
>
>http://www.home.earthlink.net/~christrask/Paper007.html
>
> I built this one with BFQ19+BQ149+J174+J310 all in SMD parts.
>
> (J270 is a better choice than J174 which tends to forward bias)
>
> With my primitive measurement methods, it was flat to 100 MHz
> and tapered off just short of 800MHz.
>
> In the other end it reliably pulls out the Russian ELF (OMEGA like)
> navigation system down around 10kHz.
>
> Chris mentioned that a kit might be underway, but I havn't seen
> any sign of it anywhere...
>
> --
> Poul-Henning Kamp   | UNIX since Zilog Zeus 3.20
> p...@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.
>
> ___
> 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.
>
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Re: [time-nuts] Active LORAN antenna

[lists]

A Wellbrook ALA-100 will kick arse over most wire antennas. I used this unit 
with various sized loops up to about 50ft.  

I've used my loop down to about 24kHz. 
-Original Message-
From: Brooke Clarke 
Sender: time-nuts-boun...@febo.com
Date: Fri, 26 Aug 2011 13:36:29 
To: Discussion of precise time and frequency measurement
Reply-To: Discussion of precise time and frequency measurement

Subject: Re: [time-nuts] Active LORAN antenna

Hi Doug:

It turns out that the fuses AMRAD specified were way too high in current 
to keep the transformer from being smoked.  The only fuses that work are 
self resetting types.  I've added them on  the primary and secondary 
side of the transformer but have not yet reinstalled the antenna.  I get 
requests every now and then for someone to build that AMRAD antenna.  
Are you still making them?

Just sent an email to Chris Trask asking about his push pull design.

My interest in active antennas is for the low frequency area where 
quarter wave wire antennas are not practical.
For HF you can't beat wire antennas.  Active antennas, either whip or 
loop do not work as well as wire.
http://www.prc68.com/I/WireAntenna.shtml

Have Fun,

Brooke Clarke
http://www.PRC68.com
http://www.End2PartyGovernment.com/


k4...@aol.com wrote:
> Hey Brooke,How are you doing?  Are you still using that AMRAD antenna 
> preamp I made for you several years ago?  It's been several years 
> since we emailed each other and I have lost contact with you until 
> now.  Last time I heard from you, your wife had run over the coax with 
> the lawn mower and cut it into!  Just curious if that thing was still 
> working.  73's.  Doug, k4cle.
>
> Connected by DROID on Verizon Wireless
>
> -Original message-
> From: Brooke Clarke 
> To: Discussion of precise time and frequency measurement 
> 
> Sent: Fri, Aug 26, 2011 16:39:01 GMT+00:00
> Subject: Re: [time-nuts] Active LORAN antenna
>
> Hi Ulrich:
>
> You might consider the AMRAD active antenna that they designed for 
> the136 kHz ham band.
> http://www.prc68.com/I/LF-Ant.shtml
>
> or the McKay Dymec DA-100 active whip.
> http://www.prc68.com/I/DR33.shtml#DA100
>
> Have Fun,
>
> Brooke Clarke
> http://www.PRC68.com
> http://www.End2PartyGovernment.com/
>
>
> Ulrich Bangert wrote:
>> Gentlemen,
>>
>> my friend Frank and I both miss the matching actice antenna for our
>> Standford Research FS700 Loran frequency standards. We also do not 
>> have a
>> schematic of it. Nevertheless we have tried to re-engineer the circut 
>> from
>> the part's list and the circuit description in the FS700 manual. Our 
> result
>> is shown in the accompanying schematic.pdf.
>>
>> The generator in the left in conjunction with the 10 k resistor 
>> represents
>> the expected high footpoint impedance of the very short (3 m) 
>> antenna. The
>> VDD in the right in conjunction with the 100 ohms resistor represents 
>> what
>> it believed to be inside the FS700.
>>
>> Not shown here is a 100 k resistor that may be included between the 
>> filter
>> output and the 7 k resistor to form a 30 dB divider together with it. 
>> Also
>> not shown is a 390 micro henry inductance which's impact is not to be 
> found
>> in the circuit descripion. Also not shown is a small neon bulb for
>> overvoltage protection.
>>
>> The ac analysis shows that the overall filter function is well around 
>> 100
>> kHz. But it seems as if the fet (a 2N5991 in the original) would not 
>> have
>> enough gain to counteract the overall damping included in the front end 
> let
>> alone to deliver some additional gain for the receiver's front end.
>>
>> We both feed the receiver currently with dipoles for 80 m ham radio 
>> and a
>> resistor that makes the receiver think the active antenna is connected. 
> The
>> receiver has a possible total of 130 dB gain and my receiver says it 
>> uses 
> 94
>> dB gain while Franks receiver says it uses 102 dB gain. The noise margin 
> is
>> also a bit better on my location. However, if one looks at the manual 
>> f.e.
>> at page 17 one could get the impression as if a receiver gain of 75 
>> dB may
>> be considered much more normal as our values. Instead of improving the
>> reception everything gets even worse if the active antenna is 
>> connected. I
>> should also note that my qth is only 200 km away from SYLT (our German 
> Loran
>> station) while Frank is even 70 km nearer to it.
>>
>> Questions:
>>
>> 1) Anyone an idea what we are possibly doing wrong?
>>
>> 2) Anyone an idea for the 390 micro henry inductor?
>>
>> 3) Anyone own the original schematic?
>>
>> TIA for your help
>>
>> Ulrich Bangert
>> www.ulrich-bangert.de
>> Ortholzer Weg 1
>> 27243 Gross Ippener
>>
>>
>> ___
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>> and follow the instructions there.
>
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[time-nuts] Dead CBT

[wa1zms]

Paul-

Check rcvd. Thanks!

I your post where you wnted to talk to Corby. Maybe he can
work some life out of that tube.  Please let me know.

Alsoif you ever cut it open, remember to send me pix!

73,
-Brian, WA1ZMS


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Re: [time-nuts] Dead CBT

[paul swed]

Hi Brian good to hear the check arrived.
I will send pix if I cut it open.
Several comments
On Corby I am taking one final run at the original tube.
He helped me with a change I would need to make to try the one you sent.
By the way it pumped down just fine with a 3500 volt supply. Thats amazing.
If all that fails I guess I am going to see exactly how tough that metal is.
Other comment. It so happens I know a person who will give the very best
guidance in a CBT disassembly. Plus has serious tools for the job. Min
damage to stuff.

But at that stage there will be pictures. I imagine lots of time-nuts would
like to see the real insides. Don't know if I want to actually break the
glass though.
Haven't figured the radioactive or not issue.
Regards and thanks.
Paul
WB8TSL


On Fri, Aug 26, 2011 at 8:33 PM,  wrote:

> Paul-
>
> Check rcvd. Thanks!
>
> I your post where you wnted to talk to Corby. Maybe he can
> work some life out of that tube.  Please let me know.
>
> Alsoif you ever cut it open, remember to send me pix!
>
> 73,
> -Brian, WA1ZMS
>
>
> ___
> 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.
>
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Re: [time-nuts] Dead CBT

[EWKehren]

If any one wants pictures of the internal guts of a HP CBT I have two  
decorating my window sill. One is the RF cavity of a high performance tube. I  
can take some pictures and send them.
Bert
 
 
In a message dated 8/26/2011 9:00:31 P.M. Eastern Daylight Time,  
paulsw...@gmail.com writes:

Hi Brian  good to hear the check arrived.
I will send pix if I cut it  open.
Several comments
On Corby I am taking one final run at the  original tube.
He helped me with a change I would need to make to try the  one you sent.
By the way it pumped down just fine with a 3500 volt supply.  Thats amazing.
If all that fails I guess I am going to see exactly how  tough that metal 
is.
Other comment. It so happens I know a person who will  give the very best
guidance in a CBT disassembly. Plus has serious tools  for the job. Min
damage to stuff.

But at that stage there will be  pictures. I imagine lots of time-nuts would
like to see the real insides.  Don't know if I want to actually break the
glass though.
Haven't figured  the radioactive or not issue.
Regards and  thanks.
Paul
WB8TSL


On Fri, Aug 26, 2011 at 8:33 PM,   wrote:

> Paul-
>
> Check rcvd.  Thanks!
>
> I your post where you wnted to talk to Corby. Maybe he  can
> work some life out of that tube.  Please let me  know.
>
> Alsoif you ever cut it open, remember to send me  pix!
>
> 73,
> -Brian, WA1ZMS
>
>
>  ___
> time-nuts mailing list  -- time-nuts@febo.com
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>
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Re: [time-nuts] Dead CBT

[paul swed]

Bert sure I would love to see what they look like.
In all the various documents they only have drawings

On Fri, Aug 26, 2011 at 9:15 PM,  wrote:

> If any one wants pictures of the internal guts of a HP CBT I have two
> decorating my window sill. One is the RF cavity of a high performance tube.
> I
> can take some pictures and send them.
> Bert
>
>
> In a message dated 8/26/2011 9:00:31 P.M. Eastern Daylight Time,
> paulsw...@gmail.com writes:
>
> Hi Brian  good to hear the check arrived.
> I will send pix if I cut it  open.
> Several comments
> On Corby I am taking one final run at the  original tube.
> He helped me with a change I would need to make to try the  one you sent.
> By the way it pumped down just fine with a 3500 volt supply.  Thats
> amazing.
> If all that fails I guess I am going to see exactly how  tough that metal
> is.
> Other comment. It so happens I know a person who will  give the very best
> guidance in a CBT disassembly. Plus has serious tools  for the job. Min
> damage to stuff.
>
> But at that stage there will be  pictures. I imagine lots of time-nuts
> would
> like to see the real insides.  Don't know if I want to actually break the
> glass though.
> Haven't figured  the radioactive or not issue.
> Regards and  thanks.
> Paul
> WB8TSL
>
>
> On Fri, Aug 26, 2011 at 8:33 PM,   wrote:
>
> > Paul-
> >
> > Check rcvd.  Thanks!
> >
> > I your post where you wnted to talk to Corby. Maybe he  can
> > work some life out of that tube.  Please let me  know.
> >
> > Alsoif you ever cut it open, remember to send me  pix!
> >
> > 73,
> > -Brian, WA1ZMS
> >
> >
> >  ___
> > 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.
> >
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[time-nuts] FS: HP Z3801A

[Joseph Gray]

I am getting rid of some extra stuff. I have a Z3801A for sale. This
unit is original and unmodified. It has been on the shelf for a while,
but worked just fine the last time it was used. You guys know how much
these go for, so make me an offer.

Joe Gray
W5JG

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