BD
Bill Dailey
Thu, Sep 19, 2013 3:59 PM
You shouldn't be seeing a 2Hz spread. It can happen but in my experience that is big. Check gain control and make sure you aren't seeing artifacts. There is an fmt-nuts on yahoo which may be more appropriate for this.
Doc
Sent from mobile
On Sep 19, 2013, at 10:32 AM, "quartz55" quartz55@hughes.net wrote:
I knew it was not that easy. I didn't think about WWVB, and yes, I hear them quite often on 20. So it's just a matter of averaging what you can measure and assuming that the average will be close? I can imagine the shift can be all one way or the other for extended periods and how would anyone know which way? I'll have to check another signal that I know is not a double and see what I see. With SpecLab, it's easy to see mHz, but it's constantly changing so I guess one needs to log the data and use the spreadsheet to average it and hope it's close. The other thing is the 2000 wanders around especially when the fan goes on, so I've got a circuit to lock the MO to a GPS. XRef-VS, there are others for other radios too. We'll see what happens when I get the XRef installed and working.
When I saw the WWV/B? signals I figured it was just how lucky you were. If I'm seeing 2 Hz spread how can anything be measured with precision? You can get close to anything once, it's doing it all the time that counts.
Dave
N3DT
----- Original Message -----
From: Dan Rae
To: Discussion of precise time and frequency measurement
Sent: Thursday, September 19, 2013 10:07 AM
Subject: Re: [time-nuts] Doppler and FMT
On 9/19/2013 6:48 AM, quartz55 wrote:
I was playing with SpecLab and my TS-2000 just to see how accurately I could measure frequencies in the HF region. I notice when I set the rx on cw and listen to the 750 Hz output of WWV at 15 or 20 MHz with SL, I get like 2 and sometimes more tracks about 2 Hz apart constantly shifting around. I assume this is Doppler going in and out? If that's so, how can anyone reasonably expect to measure any ionospheric HF signal in the mHz range?
Dave, it's not that easy. I did the ARRL FMTs a few years back when
they were transmitting from the other side of the States and thought I
was doing well to get within 0.1 Hz. The phase shifts on 7 and 14 MHz I
was seeing due to Doppler were up to 360 degrees, and quite rapid.
Mind you I was using non computer techniques [1], so averaging by
eyeball was possible.
Also if you are using WWV / WWVH, here at least, you often get both
signals at similar strength, so you might well be seeing two different
offsets.
Dan
ac6ao
[1] looking at the 100 kHz IF output of the receiver on a scope, both
scope trigger and Rx reference driven by homebrew GPS unit.
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You shouldn't be seeing a 2Hz spread. It can happen but in my experience that is big. Check gain control and make sure you aren't seeing artifacts. There is an fmt-nuts on yahoo which may be more appropriate for this.
Doc
Sent from mobile
> On Sep 19, 2013, at 10:32 AM, "quartz55" <quartz55@hughes.net> wrote:
>
> I knew it was not that easy. I didn't think about WWVB, and yes, I hear them quite often on 20. So it's just a matter of averaging what you can measure and assuming that the average will be close? I can imagine the shift can be all one way or the other for extended periods and how would anyone know which way? I'll have to check another signal that I know is not a double and see what I see. With SpecLab, it's easy to see mHz, but it's constantly changing so I guess one needs to log the data and use the spreadsheet to average it and hope it's close. The other thing is the 2000 wanders around especially when the fan goes on, so I've got a circuit to lock the MO to a GPS. XRef-VS, there are others for other radios too. We'll see what happens when I get the XRef installed and working.
>
> When I saw the WWV/B? signals I figured it was just how lucky you were. If I'm seeing 2 Hz spread how can anything be measured with precision? You can get close to anything once, it's doing it all the time that counts.
>
> Dave
> N3DT
> ----- Original Message -----
> From: Dan Rae
> To: Discussion of precise time and frequency measurement
> Sent: Thursday, September 19, 2013 10:07 AM
> Subject: Re: [time-nuts] Doppler and FMT
>
>
>> On 9/19/2013 6:48 AM, quartz55 wrote:
>> I was playing with SpecLab and my TS-2000 just to see how accurately I could measure frequencies in the HF region. I notice when I set the rx on cw and listen to the 750 Hz output of WWV at 15 or 20 MHz with SL, I get like 2 and sometimes more tracks about 2 Hz apart constantly shifting around. I assume this is Doppler going in and out? If that's so, how can anyone reasonably expect to measure any ionospheric HF signal in the mHz range?
> Dave, it's not that easy. I did the ARRL FMTs a few years back when
> they were transmitting from the other side of the States and thought I
> was doing well to get within 0.1 Hz. The phase shifts on 7 and 14 MHz I
> was seeing due to Doppler were up to 360 degrees, and quite rapid.
>
> Mind you I was using non computer techniques [1], so averaging by
> eyeball was possible.
>
> Also if you are using WWV / WWVH, here at least, you often get both
> signals at similar strength, so you might well be seeing two different
> offsets.
>
> Dan
>
> ac6ao
>
> [1] looking at the 100 kHz IF output of the receiver on a scope, both
> scope trigger and Rx reference driven by homebrew GPS unit.
> _______________________________________________
> 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.
>
>
> -----
> No virus found in this message.
> Checked by AVG - www.avg.com
> Version: 10.0.1432 / Virus Database: 3222/6180 - Release Date: 09/19/13
> _______________________________________________
> 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.
BC
Bob Camp
Thu, Sep 19, 2013 9:48 PM
Hi
With a Trimble TBolt, when you do an auto-cal it comes up with a sensitivity of the OCXO, and modifies the filter (as in the PID control loop filter) coefficients. You can then save them to the eeprom / flash in the TBolt. The settings persist across multiple reboots. The settings do impact the way the TBolt functions. This allows you to use OCXO's with different sensitivities (and even control polarity) in the TBolt.
In the Trimble NTBW50 (and Trimble made clones) you can run the auto cal via LH. The sensitivity is calculated and may appear to change. The settings can not be saved in flash / eeprom. They do not persist across multiple reboots. There is no evidence that the NTBW50 actually uses the changed settings.
Switching elevation masks, changing AMU limits, works with both units. These changes do save to flash / eeprom on both units. They persist across multiple reboots on both. The do impact the way both units function.
My guess is that the antenna you have is virtually identical to the Lucent 26 db gain device. I doubt that the cost of getting one is worth the money. If you want a better antenna, go for one of the $300 - $500 choke ring antennas. You will also need a bias Tee (they mostly run on 12 volts), but it's often included.
Enjoy!
Bob
On Sep 19, 2013, at 9:40 AM, "quartz55" quartz55@hughes.net wrote:
Thanks Bob, Charles,
Well, here's my plan. Get a single piece of RG-11 direct burial. Get a more stable post for the antenna and perhaps a bit taller. Keep my eye out for a different antenna, right now they seem to be going for $50 and up for the 26 dB versions, I could contact RDR, but I didn't see anything on his site about other antennas. Yes, this is no high RF area except when maybe I turn on the 170 W 2M brick and that's nothing, I saw that thread about filters in the antenna. Finish this 48 hour survey and get these other things done and then do a 72 hour survey. Let it run for months and see where we are. Get a smaller switching type power supply.
I figured nothing was broken or not working right.
Bob, are you saying playing with the masks TC, gain and other stuff in LH does nothing to the NTBW50AA? It just affects how LH looks on my computer screen and I'm really not changing anything of how the Nortel works?
Thanks,
Dave
----- Original Message -----
From: Bob Camp
To: Discussion of precise time and frequency measurement
Sent: Thursday, September 19, 2013 7:23 AM
Subject: Re: [time-nuts] New NTBW50AA
HI
What can be said with reasonable confidence:
- The unit isn't broken and it does not need to go back to RDR under their 30 day return policy.
- The OCXO isn't broken and it does not need to be replaced.
- The unit is functioning ok, but probably not as good as it could.
- Without comparison to an independent standard, there's no way to know how well it is or isn't doing.
Bob
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Hi
With a Trimble TBolt, when you do an auto-cal it comes up with a sensitivity of the OCXO, and modifies the filter (as in the PID control loop filter) coefficients. You can then save them to the eeprom / flash in the TBolt. The settings persist across multiple reboots. The settings do impact the way the TBolt functions. This allows you to use OCXO's with different sensitivities (and even control polarity) in the TBolt.
In the Trimble NTBW50 (and Trimble made clones) you can run the auto cal via LH. The sensitivity is calculated and may appear to change. The settings can not be saved in flash / eeprom. They do not persist across multiple reboots. There is no evidence that the NTBW50 actually uses the changed settings.
Switching elevation masks, changing AMU limits, works with both units. These changes do save to flash / eeprom on both units. They persist across multiple reboots on both. The do impact the way both units function.
-----------------
My guess is that the antenna you have is virtually identical to the Lucent 26 db gain device. I doubt that the cost of getting one is worth the money. If you want a better antenna, go for one of the $300 - $500 choke ring antennas. You will also need a bias Tee (they mostly run on 12 volts), but it's often included.
Enjoy!
Bob
On Sep 19, 2013, at 9:40 AM, "quartz55" <quartz55@hughes.net> wrote:
> Thanks Bob, Charles,
>
> Well, here's my plan. Get a single piece of RG-11 direct burial. Get a more stable post for the antenna and perhaps a bit taller. Keep my eye out for a different antenna, right now they seem to be going for $50 and up for the 26 dB versions, I could contact RDR, but I didn't see anything on his site about other antennas. Yes, this is no high RF area except when maybe I turn on the 170 W 2M brick and that's nothing, I saw that thread about filters in the antenna. Finish this 48 hour survey and get these other things done and then do a 72 hour survey. Let it run for months and see where we are. Get a smaller switching type power supply.
>
> I figured nothing was broken or not working right.
>
> Bob, are you saying playing with the masks TC, gain and other stuff in LH does nothing to the NTBW50AA? It just affects how LH looks on my computer screen and I'm really not changing anything of how the Nortel works?
>
> Thanks,
> Dave
> ----- Original Message -----
> From: Bob Camp
> To: Discussion of precise time and frequency measurement
> Sent: Thursday, September 19, 2013 7:23 AM
> Subject: Re: [time-nuts] New NTBW50AA
>
>
> HI
>
> What can be said with reasonable confidence:
>
> 1) The unit isn't broken and it does not need to go back to RDR under their 30 day return policy.
> 2) The OCXO isn't broken and it does not need to be replaced.
> 3) The unit is functioning ok, but probably not as good as it could.
> 4) Without comparison to an independent standard, there's no way to know how well it is or isn't doing.
>
> 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.
BC
Bob Camp
Thu, Sep 19, 2013 11:37 PM
Hi
Remember - there's more than one station on 5, 10, 15 and 20 MHz. You may be picking up the modulation from one of them. Ionospheric shift can easily give you a few Hz on HF.
Back when I was doing FMT stuff there was no ionosphere involved. I was within ground wave of Newington ….
Bob
On Sep 19, 2013, at 9:48 AM, quartz55 quartz55@hughes.net wrote:
I was playing with SpecLab and my TS-2000 just to see how accurately I could measure frequencies in the HF region. I notice when I set the rx on cw and listen to the 750 Hz output of WWV at 15 or 20 MHz with SL, I get like 2 and sometimes more tracks about 2 Hz apart constantly shifting around. I assume this is Doppler going in and out? If that's so, how can anyone reasonably expect to measure any ionospheric HF signal in the mHz range?
Dave
N3DT
time-nuts mailing list -- time-nuts@febo.com
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and follow the instructions there.
Hi
Remember - there's more than one station on 5, 10, 15 and 20 MHz. You may be picking up the modulation from one of them. Ionospheric shift can easily give you a few Hz on HF.
Back when I was doing FMT stuff there was no ionosphere involved. I was within ground wave of Newington ….
Bob
On Sep 19, 2013, at 9:48 AM, quartz55 <quartz55@hughes.net> wrote:
> I was playing with SpecLab and my TS-2000 just to see how accurately I could measure frequencies in the HF region. I notice when I set the rx on cw and listen to the 750 Hz output of WWV at 15 or 20 MHz with SL, I get like 2 and sometimes more tracks about 2 Hz apart constantly shifting around. I assume this is Doppler going in and out? If that's so, how can anyone reasonably expect to measure any ionospheric HF signal in the mHz range?
>
> Dave
> N3DT
> _______________________________________________
> 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.
TV
Tom Van Baak
Fri, Sep 20, 2013 12:17 AM
So it's just a matter of averaging what you can measure
and assuming that the average will be close?
Two quick comments.
-
A gradual phase drift over time is identical (by definition) to a frequency offset.
-
In general, "averaging" a moving target gets you less accuracy, not more.
We learned in school that averaging enhances accuracy. This is true in textbook cases where the mean is constant and where the distribution of error about the mean is symmetrical.
But when working with clocks (time, frequency, stability measurements) this assumption often not true and it's helpful to think of averaging more as a disease than a cure.
/tvb
> So it's just a matter of averaging what you can measure
> and assuming that the average will be close?
Two quick comments.
1) A gradual phase drift over time is identical (by definition) to a frequency offset.
2) In general, "averaging" a moving target gets you *less* accuracy, not more.
We learned in school that averaging enhances accuracy. This is true in textbook cases where the mean is constant and where the distribution of error about the mean is symmetrical.
But when working with clocks (time, frequency, stability measurements) this assumption often not true and it's helpful to think of averaging more as a disease than a cure.
/tvb
BC
Bob Camp
Fri, Sep 20, 2013 12:35 AM
Hi
As with most complex questions the real answer is "that depends" …
Blind averaging will indeed get you in trouble. Curve fitting (a straight line is a simple one) often is the better approach to phase data. You can get an "averaging like" improvement (square root of the number of samples). You need to use a technique that fits the data and the noise you have on the data.
Bob
On Sep 19, 2013, at 8:17 PM, Tom Van Baak tvb@LeapSecond.com wrote:
So it's just a matter of averaging what you can measure
and assuming that the average will be close?
Two quick comments.
-
A gradual phase drift over time is identical (by definition) to a frequency offset.
-
In general, "averaging" a moving target gets you less accuracy, not more.
We learned in school that averaging enhances accuracy. This is true in textbook cases where the mean is constant and where the distribution of error about the mean is symmetrical.
But when working with clocks (time, frequency, stability measurements) this assumption often not true and it's helpful to think of averaging more as a disease than a cure.
/tvb
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.
Hi
As with most complex questions the real answer is "that depends" …
Blind averaging will indeed get you in trouble. Curve fitting (a straight line is a simple one) often is the better approach to phase data. You can get an "averaging like" improvement (square root of the number of samples). You need to use a technique that fits the data and the noise you have on the data.
Bob
On Sep 19, 2013, at 8:17 PM, Tom Van Baak <tvb@LeapSecond.com> wrote:
>> So it's just a matter of averaging what you can measure
>> and assuming that the average will be close?
>
> Two quick comments.
>
> 1) A gradual phase drift over time is identical (by definition) to a frequency offset.
>
> 2) In general, "averaging" a moving target gets you *less* accuracy, not more.
>
> We learned in school that averaging enhances accuracy. This is true in textbook cases where the mean is constant and where the distribution of error about the mean is symmetrical.
>
> But when working with clocks (time, frequency, stability measurements) this assumption often not true and it's helpful to think of averaging more as a disease than a cure.
>
> /tvb
>
>
> _______________________________________________
> 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.
Q
quartz55
Fri, Sep 20, 2013 2:32 AM
In the Trimble NTBW50 (and Trimble made clones) you can run the auto cal via LH. The sensitivity is calculated and may appear to change. The settings can not be saved in flash / eeprom. They do not persist across multiple reboots. There is no evidence that the NTBW50 actually uses the changed settings.
Switching elevation masks, changing AMU limits, works with both units. These changes do save to flash / eeprom on both units. They persist across multiple reboots on both. The do impact the way both units function.
Bob, I suppose you came across this by experimentation, not by any instruction booklet? I guess we're on our own here with the Nortel units. How about Mark's (I think) suggestion to "set the EL mask to a low value (F E 0), clear the signal data (S A C) let the unit run for a day or so, then do the osc autotune (&A). This will set the elevation mask to a level that matches what your antenna can see. Or you can check the elevation plot (S A E) and see where the tick mark shows the signal level dropping off and enter that value manually."
My guess is that the antenna you have is virtually identical to the Lucent 26 db gain device. I doubt that the cost of getting one is worth the money. If you want a better antenna, go for one of the $300 - $500 choke ring antennas. You will also need a bias Tee (they mostly run on 12 volts), but it's often included.
Well, that's not going to happen, the $3-500 anyhow. I was also thinking about the filter, aren't all the L1 sats on the same freq, so there shouldn't be any phase difference with respect to the sats, but I may be way off base here.
I found a nice 15' locust log today that's about 6-8" dia. that I can strap to one of the fence posts and get rid of the 3/4" EMT. Wife likes it too because it looks 'rustic'. Cool.
Thanks, Dave
In the Trimble NTBW50 (and Trimble made clones) you can run the auto cal via LH. The sensitivity is calculated and may appear to change. The settings can not be saved in flash / eeprom. They do not persist across multiple reboots. There is no evidence that the NTBW50 actually uses the changed settings.
Switching elevation masks, changing AMU limits, works with both units. These changes do save to flash / eeprom on both units. They persist across multiple reboots on both. The do impact the way both units function.
Bob, I suppose you came across this by experimentation, not by any instruction booklet? I guess we're on our own here with the Nortel units. How about Mark's (I think) suggestion to "set the EL mask to a low value (F E 0), clear the signal data (S A C) let the unit run for a day or so, then do the osc autotune (&A). This will set the elevation mask to a level that matches what your antenna can see. Or you can check the elevation plot (S A E) and see where the tick mark shows the signal level dropping off and enter that value manually."
My guess is that the antenna you have is virtually identical to the Lucent 26 db gain device. I doubt that the cost of getting one is worth the money. If you want a better antenna, go for one of the $300 - $500 choke ring antennas. You will also need a bias Tee (they mostly run on 12 volts), but it's often included.
Well, that's not going to happen, the $3-500 anyhow. I was also thinking about the filter, aren't all the L1 sats on the same freq, so there shouldn't be any phase difference with respect to the sats, but I may be way off base here.
I found a nice 15' locust log today that's about 6-8" dia. that I can strap to one of the fence posts and get rid of the 3/4" EMT. Wife likes it too because it looks 'rustic'. Cool.
Thanks, Dave
Q
quartz55
Fri, Sep 20, 2013 2:34 AM
But when working with clocks (time, frequency, stability measurements) this assumption often not true and it's helpful to think of averaging more as a disease than a cure.
/tvb
I can understand that.
Dave
But when working with clocks (time, frequency, stability measurements) this assumption often not true and it's helpful to think of averaging more as a disease than a cure.
/tvb
I can understand that.
Dave
BC
Bob Camp
Fri, Sep 20, 2013 11:29 AM
Hi
There is no instruction booklet for the NTBW50's and LH. The program is targeted at a TBolt. I think it's great that it happens to work at all for the NTBW50. The stuff about the filter settings has been noted by and posted by several members here on the list. I've seen it on my units here.
Setting the elevation mask on any of these units can be done from AMU plots. The gottcha there is that multi path issues will cut in before the signal strength drops off. You want to set it a bit higher than the drop off point. Multipath can be a much larger issue than simple signal to noise. It's the path delay in multi path that's the problem.
The sat's are all on the same frequency. However they are moving at a very high rate of speed. That creates a doppler shift in the frequency. You have to track out the doppler before you can even receive the signal. It's also why you can't use the GPS frequency directly as a reference for the GPSDO. Weather the shift is big enough to matter is indeed a matter of conjecture. Without actual filter data, there's no way to really know.
As you move the antenna around remember that keeping the GPSDO on power is the main goal. You don't have to keep it connected to an antenna as you relocate, but don't take the OCXO off power. They very much prefer to be run continuously.
Bob
On Sep 19, 2013, at 10:32 PM, quartz55 quartz55@hughes.net wrote:
In the Trimble NTBW50 (and Trimble made clones) you can run the auto cal via LH. The sensitivity is calculated and may appear to change. The settings can not be saved in flash / eeprom. They do not persist across multiple reboots. There is no evidence that the NTBW50 actually uses the changed settings.
Switching elevation masks, changing AMU limits, works with both units. These changes do save to flash / eeprom on both units. They persist across multiple reboots on both. The do impact the way both units function.
Bob, I suppose you came across this by experimentation, not by any instruction booklet? I guess we're on our own here with the Nortel units. How about Mark's (I think) suggestion to "set the EL mask to a low value (F E 0), clear the signal data (S A C) let the unit run for a day or so, then do the osc autotune (&A). This will set the elevation mask to a level that matches what your antenna can see. Or you can check the elevation plot (S A E) and see where the tick mark shows the signal level dropping off and enter that value manually."
My guess is that the antenna you have is virtually identical to the Lucent 26 db gain device. I doubt that the cost of getting one is worth the money. If you want a better antenna, go for one of the $300 - $500 choke ring antennas. You will also need a bias Tee (they mostly run on 12 volts), but it's often included.
Well, that's not going to happen, the $3-500 anyhow. I was also thinking about the filter, aren't all the L1 sats on the same freq, so there shouldn't be any phase difference with respect to the sats, but I may be way off base here.
I found a nice 15' locust log today that's about 6-8" dia. that I can strap to one of the fence posts and get rid of the 3/4" EMT. Wife likes it too because it looks 'rustic'. Cool.
Thanks, Dave
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.
Hi
There is no instruction booklet for the NTBW50's and LH. The program is targeted at a TBolt. I think it's great that it happens to work at all for the NTBW50. The stuff about the filter settings has been noted by and posted by several members here on the list. I've seen it on my units here.
Setting the elevation mask on any of these units can be done from AMU plots. The gottcha there is that multi path issues will cut in before the signal strength drops off. You want to set it a bit higher than the drop off point. Multipath can be a much larger issue than simple signal to noise. It's the path delay in multi path that's the problem.
The sat's are all on the same frequency. However they are moving at a very high rate of speed. That creates a doppler shift in the frequency. You have to track out the doppler before you can even receive the signal. It's also why you can't use the GPS frequency directly as a reference for the GPSDO. Weather the shift is big enough to matter is indeed a matter of conjecture. Without actual filter data, there's no way to really know.
As you move the antenna around remember that keeping the GPSDO on power is the main goal. You don't have to keep it connected to an antenna as you relocate, but don't take the OCXO off power. They very much prefer to be run continuously.
Bob
On Sep 19, 2013, at 10:32 PM, quartz55 <quartz55@hughes.net> wrote:
> In the Trimble NTBW50 (and Trimble made clones) you can run the auto cal via LH. The sensitivity is calculated and may appear to change. The settings can not be saved in flash / eeprom. They do not persist across multiple reboots. There is no evidence that the NTBW50 actually uses the changed settings.
>
> Switching elevation masks, changing AMU limits, works with both units. These changes do save to flash / eeprom on both units. They persist across multiple reboots on both. The do impact the way both units function.
>
> Bob, I suppose you came across this by experimentation, not by any instruction booklet? I guess we're on our own here with the Nortel units. How about Mark's (I think) suggestion to "set the EL mask to a low value (F E 0), clear the signal data (S A C) let the unit run for a day or so, then do the osc autotune (&A). This will set the elevation mask to a level that matches what your antenna can see. Or you can check the elevation plot (S A E) and see where the tick mark shows the signal level dropping off and enter that value manually."
>
> My guess is that the antenna you have is virtually identical to the Lucent 26 db gain device. I doubt that the cost of getting one is worth the money. If you want a better antenna, go for one of the $300 - $500 choke ring antennas. You will also need a bias Tee (they mostly run on 12 volts), but it's often included.
>
> Well, that's not going to happen, the $3-500 anyhow. I was also thinking about the filter, aren't all the L1 sats on the same freq, so there shouldn't be any phase difference with respect to the sats, but I may be way off base here.
>
> I found a nice 15' locust log today that's about 6-8" dia. that I can strap to one of the fence posts and get rid of the 3/4" EMT. Wife likes it too because it looks 'rustic'. Cool.
>
> Thanks, Dave
> _______________________________________________
> 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.
Q
quartz55
Fri, Sep 20, 2013 1:36 PM
I may also look into a DIY choke ring for my antenna. With the large pole I have now, it will be no problem to put a rather large ground plane under the antenna if that will help. I'll do some searching on that.
I'll keep the thing running, but I may have to switch it at some point if I get a smaller PS. We have plenty outages here, so I may look into a UPS of some sort but I have a rather large generator that I always turn on after about 1/2 hour or so.
80% through the 48 hour survey. I also ordered 150' of RG-11/underground.
Thanks,
Dave
I may also look into a DIY choke ring for my antenna. With the large pole I have now, it will be no problem to put a rather large ground plane under the antenna if that will help. I'll do some searching on that.
I'll keep the thing running, but I may have to switch it at some point if I get a smaller PS. We have plenty outages here, so I may look into a UPS of some sort but I have a rather large generator that I always turn on after about 1/2 hour or so.
80% through the 48 hour survey. I also ordered 150' of RG-11/underground.
Thanks,
Dave
CS
Charles Steinmetz
Fri, Sep 20, 2013 5:01 PM
We have plenty outages here, so I may look into a UPS of some sort
but I have a rather large generator that I always turn on after
about 1/2 hour or so.
The UPS is to keep master oscillators (and for some of us, ovenized
voltage standards) running uninterrupted from the time of the failure
until the generator is running. Best practice is to use a "double
conversion" UPS to avoid even a short outage as it kicks in.
Best regards,
Charles
Dave wrote:
>We have plenty outages here, so I may look into a UPS of some sort
>but I have a rather large generator that I always turn on after
>about 1/2 hour or so.
The UPS is to keep master oscillators (and for some of us, ovenized
voltage standards) running uninterrupted from the time of the failure
until the generator is running. Best practice is to use a "double
conversion" UPS to avoid even a short outage as it kicks in.
Best regards,
Charles
