I've been reading and researching what I will need to connect a Spectracom
8182 Netclock/2 for use here at home as a WWV(B) clock.

I found a post response from Feb 23, 2005 by Brian Kirby which includes the
a link for a preamplifier schematic here:

<http://www.febo.com/pipermail/time-nuts/attachments/20050223/94b9bd2c/attac
hment-0008.pdf>
http://www.febo.com/pipermail/time-nuts/attachments/20050223/94b9bd2c/attach
ment-0008.pdf

According to all information I have been able to gather, in California I
really don't a preamplifier.  However the Spectracom 8182 manual discusses
the use of a preamplifier (8207) with their antenna as "part of the system".

My train of thought is, the 8182 superimposes 10.7vdc on the antenna BNC for
powering the inline preamplifier.  If I do not use the preamplifier will
this DC voltage create problems and attenuate the RF signal? Will the
comparator circuit in the 8182 show the antenna to be open and therefore not
operate correctly?  Would a decoupling network to prevent the DC voltage
from reaching the antenna create the same problem?

Lastly I see in the preamplifier schematic DC power is used to power the
transistors (+9 input) and how 60Khz is 80 mV P-P amplified signal is shown
as an output signal (near Q4).  I must be missing something as it doesn't
show how the RF signal coupled back to the input, unless of course C8 (the
1.0uf capacitor) is how it is coupled back.

There are several jumpers within the 8182 but the manual does not seem
discuss these. The datasheet for the 8165 disciplined oscillator discusses
on Page 5 about the "Switch A1S1" which will appears to enable/disable the
DC preamplifier voltage.

https://www.atecorp.com/ATECorp/media/pdfs/data-sheets/Spectracom-8206_Manua
l.pdf

Thanks

Donald Resor

N6KAW

I remember being told about this years ago, but it had not registered in my mind recently that it was the format which had changed.  For some reason I thought it was the transmission frequency.

I'm a little baffled though, I purchased both of my SkyScan clocks, prior to these changes.  Yet they both still set themselves (when propagation allows) correctly.  One would think inexpensive products would be sacrificed verses the more expensive equipment.

What are example(s) of the "gizmo" which will convert the new format to the old one?

I realized later after reading more about the antenna I am looking at that it has a DC blocking capacitor built in, therefore it should be fine.  This is what happens when I spend too much time during the wee hours of the night/morning with a mind which becomes even more cloudy.

Thanks

Donald Resor
N6KAW

-----Original Message-----
From: time-nuts time-nuts-bounces@febo.com On Behalf Of Bob kb8tq
Sent: Thursday, March 22, 2018 8:13 AM
To: Discussion of precise time and frequency measurement time-nuts@febo.com
Subject: Re: [time-nuts] WWVB Antenna revisited/Spectracom 8182

Hi

You should DC block the output of the 8182 if you are going to run it straight to an antenna.

The bigger issue is that WWVB changed their transmit format a couple years ago. The signal they now send is not compatible with a lot of gear out there.
It turns out that the 8182 is included on that list:

https://spectracom.com/support/retired-products/netclock?field_product_availability_ref_tid=94 https://spectracom.com/support/retired-products/netclock?field_product_availability_ref_tid=94

There are gizmos you can build to convert the new transmit format to the old one, I’m not sure if you are interested in going to that extreme.

Bob

Donald,

Your Skyscan radio clock, as well as all other consumer-grade WWVB clocks & watches, will continue to work. The new format was designed to be compatible with the old format so any receiver that gets time only from the AM subcode will continue to work.

It's the commercial time & frequency receivers that don't work anymore. This is because the new format creates rapid phase shifts in the 60 kHz carrier which break the PLL design used in legacy receivers.

There's tons of time-nuts postings over the years on the subject. If you want a fun h/w and s/w project you can solve the problem for your receiver. Or google a bit and find some WWVB emulator projects which mimic the old signal well enough to keep receivers like Spectracom happy. Plus you won't need to hunt for a loop antenna for your 8182.

If you just want a home clock that's accurate at the sub-second level, consider a computer (NTP) or time.gov or GPS or GPSDO or smart phone or even NIST dial-up. Over the decades we've lost Omega, GOES, Loran-C and the carrier part of WWVB. But when you think of it, cell phones, the internet, and GPS (and GLONASS, Galileo, Beidou) are a pretty good replacement for those vintage time services.

/tvb

----- Original Message -----
From: "D. Resor" organlists@pacbell.net
To: "'Discussion of precise time and frequency measurement'" time-nuts@febo.com
Sent: Thursday, March 22, 2018 12:13 PM
Subject: Re: [time-nuts] WWVB Antenna revisited/Spectracom 8182

I remember being told about this years ago, but it had not registered in my mind recently that it was the format which had changed.  For some reason I thought it was the transmission frequency.

I'm a little baffled though, I purchased both of my SkyScan clocks, prior to these changes.  Yet they both still set themselves (when propagation allows) correctly.  One would think inexpensive products would be sacrificed verses the more expensive equipment.

What are example(s) of the "gizmo" which will convert the new format to the old one?

I realized later after reading more about the antenna I am looking at that it has a DC blocking capacitor built in, therefore it should be fine.  This is what happens when I spend too much time during the wee hours of the night/morning with a mind which becomes even more cloudy.

Thanks

Donald Resor
N6KAW

-----Original Message-----
From: time-nuts time-nuts-bounces@febo.com On Behalf Of Bob kb8tq
Sent: Thursday, March 22, 2018 8:13 AM
To: Discussion of precise time and frequency measurement time-nuts@febo.com
Subject: Re: [time-nuts] WWVB Antenna revisited/Spectracom 8182

Hi

You should DC block the output of the 8182 if you are going to run it straight to an antenna.

The bigger issue is that WWVB changed their transmit format a couple years ago. The signal they now send is not compatible with a lot of gear out there.
It turns out that the 8182 is included on that list:

https://spectracom.com/support/retired-products/netclock?field_product_availability_ref_tid=94 https://spectracom.com/support/retired-products/netclock?field_product_availability_ref_tid=94

There are gizmos you can build to convert the new transmit format to the old one, I’m not sure if you are interested in going to that extreme.

Bob

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.