I'm glad you showed us this. Oscillators these days show no resect for authority or others. It's honesty a huge problem. It's nice to know that there are still disciplined Oscillators out there. 😊
Very nice. The GPS antenna doesn't have to be on the roof. It only needs to see the sky, so that can be done through almost any window facing outside. Most of the time if you just sit the antenna on the windowsill it will work just fine. The alarm LED is likely tied in to the crystal oven and will be lit until it reaches temperature.
Many windows today have low-e coatings, which is a layer of metal on the glass. They're not transparent to microwaves. So next to a window might not be the best place. The GPS receivers in these are sensitive enough to work through the (non-metal) roof of a house. Mine works in my basement workshop.
@@stargazer7644 Good grief. There is always something new to put a spanner in the works. My windows don't have any special coatings on them and a GPS antenna sitting on the sill works perfectly. In fact I have a LED digital clock with GPS receiver and it sits above the fireplace against a solid wall and has no problems locking on to a dozen satellites from there - and it's nowhere near a window. I can only suspect it's receiving through the wall.
@@sw6188 The windows affected are advertised as energy saving "Low-E" or "Low Emissivity" windows. If they're tinted, you may have the same problem as some window tint (like used in office buildings) is very thin metallic film. The walls may also be a problem if you have foil backed insulation board (celotex) in the walls, or plaster or stucco walls with metal mesh in them, depending on the size of the mesh. Usually the roof is fine if you have wood construction and asphalt shingles. I have low-e windows and celotex in the walls of my house.
Nice. I also just got a GPSDO, but I went with one of Leo Bodnar's lbe-1420. It works great, and is super easy to use, but I do wish it had multiple outputs. My antenna is just sitting outside of a window on the windowsill right against the house and I am picking up 23 satellites. Currently set to output 24Mhz to be used with my SDRplay RSPDx.
The Leo Bodnar unit is the way to go if you need something other than 10 MHz. My antenna is just sitting inside the window sill and works great in that position
I got the dual BNC Bodnar unit. Part of the PLL divisor chain is shared between the two outputs, but the set-up program figures out how to shuffle the numbers to come up with the two frequencies you want - if you want two different frequencies, that is. I’ve been very pleased with the results so far. If all you need is a frequency standard, and don’t care about 1 PPS, SMPTE time codes and NTP serving, then the Bodnar units are the way to go for a very affordable cost. Better yet, they’re made in the UK by a company which will be there if you need to ask for support.
I added a Leo Bodnar Electronics GPSDO to my bench about a month ago. The Bodnar unit is made in the UK and customer support exists, though I have not needed support. There are a few models to pick from, and I opted for the dual BNC output which is about the size of a US cigarette pack. I chose this brand over the no-name Chinese units which are common on eBay and Amazon which I assume are throw-away items if problems arise. Bodnar refers to their GPSDO as a “clock” but they mean that in the sense of strictly a system frequently reference. The two outputs are independent and programmable from 450 Hz to 880 MHz using a USB set-up program. Once set. The unit no longer needs to be plugged into a computer. The power input is 3.3 to 16 Volts DC and a small USB supply is a good power source. I found the unit locked on in about 15 seconds with the antenna puck resting on my bench, which is not near a window. The stated accuracy is 1/10^11 and a pretty low phase noise error. My service monitor and spectrum analyzer have OCXOs, but with the Bodnar unit, I was able to improve the measurement accuracy by about two orders of magnitude. The GPSDO reference unit is an accuracy game changer, and now super precise frequency measurements are within reach of most hobbyists.
The ALM light is supposed to mean "Don't rely on the output frequency". The light is supposed to go off after the GPS signal has been stable for long enough that the PLL has locked and the oscillator has been tuned on frequency. The GPS Lock light means it can decode the GPS satellite signal. The blinking RUN light indicates that the software is working. I've found the PLL in these do not lock exactly on frequency and they wander by millihertz. They're close enough to use as an OK frequency standard, but they're not nearly as good as they should be. That might not be a problem if you're just using it to put your VHF ham radio on frequency or using it in place of a quartz oscillator on your 1 Hz resolution frequency counter, but if you use these as a timing source the errors compound and you'll find that your time of day clock drifts significantly and randomly where using a better unit like a Trimble Thunderbolt will stay within nanoseconds day after day. I've seen mine drift over 100ns in 30 minutes. This drift is not what one expects from an atomic referenced standard. I've found the smaller black versions of these ebay GPSDOs can still be significantly off frequency by many hertz when the ALM light first goes off. If you're wanting this for anything serious, get a used Trimble Thunderbolt instead.
I’ve been wondering what is inside the generic Chinese GPSDOs for sale on eBay and Amazon. I guessed they are using recycled Trimble modules out of other equipment. I’ve been using a Leo Bodnar unit as the frequency standard for my service monitor and spectrum analyzer. Bodnar states the frequency accuracy is 1/10^11. The phase noise is acceptable, but I’d have to look it up on Bodnar’s web site. I’m not generating SMPTE time codes or standardizing an NTP server, so I’ve found the Bodnar unit acceptable for a very reasonable cost.
I got one something like this from Aliexpress but it's rather disappointing. On the display it just says "10.000 Mhz GPSDO" for a while then changes to say "PPB -2.3" and "PWM31077" but there are no instructions at all so I have no idea what that means. Pushing in the knob gets into a menu where I can select Contrast, Offset, PWM Set and Exit but that's all. It never displays the time like they show in some photos and there's no way to even tell if it's picking up any satellites or working at all! I opened it up and inside it has an Arduino STM32 and NEO-6M module plugged into the main board with a 5 volt regulator and LCD. The main board also has a 10.000 Mhz OSCO on it and outputs on the back for 1PPM and 10 Mhz.. With the top off I can at least see the LED blinking on the NEO-6M so I guess it's working to some extent but they should have put the LED on the front. Since there are no instructions can you tell me what PPB -2.3 and PWM31077 mean and how to use the settings for Offset, PWM Set? The PPB value goes down to just a fraction after it's been on a while so I assume that is some indication of the amount of error?
Interesting bit of kit. I see they have been extensively discussed on EEVblog pages and have been around in various versions since about at least 2015. Interesting that yours has no year-month-day text marking after the BG7TBL on the front panel. Guess there are many copies of the original product with it being difficult to see if its by the original designer/producer.
If you have the opportunity measure two GPSDOs, and then have a look at the Lissajous curve! I designed a GPSDO as my thesis, I had measured it, and I think the comparison would be interesting for you as well!
@@PolyakB when I was at HP in the 1980s, we would compare the relative performance of 2 cesium beam frequency standards with a phase comparator and a strip chart recorder. It was interesting indeed. Although one might not expect any variation whatsoever between units, we could usually see some drift over time. I imagine the variation between GPSDO units is even more significant.
@@garyramsey4275 It really is! I recorded a timelapse of the two signals, triggered the scope on one of them, and they had quite a large range of phase difference.
Prices vary. You can check the prices on eBay, I’m sure they’re also available from other sites too. It’s a surprisingly sophisticated piece of tech for not very much money.
If you don't mind ordering direct from China the lowest price on eBay this morning is about $70. The lowest price I see from a U.S. address is about $90. There are quite a few options in the $200 range so take your pick.
What did you replace them with? They are still for sale and used in many devices. The next best thing, a TCXO, is not nearly as stable, but much smaller and needs less current.
This is a rip off. There is a cheaper 1/3 the price with LCD with a deviation value from the crystal oscillator in ppb and count. The most relible peice of gadgets that I own.
There are a plethora of Chinese GPSDOs on offer of Amazon and eBay. I suspect some of those units are using recycled Trimble boards which were originally in some other equipment. Despite the verbose listings, it is difficult to get a true sense of what you’re buying because the listings are clones of each other. The generic GPSDO cost isn’t huge, but it isn’t zero either. I don’t feel comfortable with the no-name eBay GPSDOs. I got a Leo Bodnar Electronics GPSDO for my bench last month. The Bodnar unit is simply a programmable frequency standard with 450 Hz - 880 MHz settable output. I feel better buying the made in UK Bodnar unit because the cost is about the same and I believe Bodnar will be around if support should be needed.
I like your unboxing segment more than any others I've seen.
Gotta agree with that.
@@ka8syv203 What does that mean?
I'm glad you showed us this. Oscillators these days show no resect for authority or others. It's honesty a huge problem. It's nice to know that there are still disciplined Oscillators out there. 😊
Lady Heather approves of this message.
Your channel is very interesting. Thanks for sharing your love for our hobby.
Probably the best unboxing video .....EVER! 🤣
In the next video can you take the covers off so we can see what the insides are like?
I can do that.
Thanks for information. I did not know you can get such accuracy without spending a fortune.
I hope this type of unboxing video catches on.
Very nice. The GPS antenna doesn't have to be on the roof. It only needs to see the sky, so that can be done through almost any window facing outside. Most of the time if you just sit the antenna on the windowsill it will work just fine.
The alarm LED is likely tied in to the crystal oven and will be lit until it reaches temperature.
Many windows today have low-e coatings, which is a layer of metal on the glass. They're not transparent to microwaves. So next to a window might not be the best place. The GPS receivers in these are sensitive enough to work through the (non-metal) roof of a house. Mine works in my basement workshop.
@@stargazer7644 Good grief. There is always something new to put a spanner in the works. My windows don't have any special coatings on them and a GPS antenna sitting on the sill works perfectly. In fact I have a LED digital clock with GPS receiver and it sits above the fireplace against a solid wall and has no problems locking on to a dozen satellites from there - and it's nowhere near a window. I can only suspect it's receiving through the wall.
@@sw6188 The windows affected are advertised as energy saving "Low-E" or "Low Emissivity" windows. If they're tinted, you may have the same problem as some window tint (like used in office buildings) is very thin metallic film. The walls may also be a problem if you have foil backed insulation board (celotex) in the walls, or plaster or stucco walls with metal mesh in them, depending on the size of the mesh. Usually the roof is fine if you have wood construction and asphalt shingles. I have low-e windows and celotex in the walls of my house.
Nice. I also just got a GPSDO, but I went with one of Leo Bodnar's lbe-1420. It works great, and is super easy to use, but I do wish it had multiple outputs. My antenna is just sitting outside of a window on the windowsill right against the house and I am picking up 23 satellites. Currently set to output 24Mhz to be used with my SDRplay RSPDx.
The Leo Bodnar unit is the way to go if you need something other than 10 MHz.
My antenna is just sitting inside the window sill and works great in that position
I got the dual BNC Bodnar unit. Part of the PLL divisor chain is shared between the two outputs, but the set-up program figures out how to shuffle the numbers to come up with the two frequencies you want - if you want two different frequencies, that is. I’ve been very pleased with the results so far. If all you need is a frequency standard, and don’t care about 1 PPS, SMPTE time codes and NTP serving, then the Bodnar units are the way to go for a very affordable cost. Better yet, they’re made in the UK by a company which will be there if you need to ask for support.
I added a Leo Bodnar Electronics GPSDO to my bench about a month ago. The Bodnar unit is made in the UK and customer support exists, though I have not needed support. There are a few models to pick from, and I opted for the dual BNC output which is about the size of a US cigarette pack. I chose this brand over the no-name Chinese units which are common on eBay and Amazon which I assume are throw-away items if problems arise.
Bodnar refers to their GPSDO as a “clock” but they mean that in the sense of strictly a system frequently reference. The two outputs are independent and programmable from 450 Hz to 880 MHz using a USB set-up program. Once set. The unit no longer needs to be plugged into a computer. The power input is 3.3 to 16 Volts DC and a small USB supply is a good power source. I found the unit locked on in about 15 seconds with the antenna puck resting on my bench, which is not near a window. The stated accuracy is 1/10^11 and a pretty low phase noise error.
My service monitor and spectrum analyzer have OCXOs, but with the Bodnar unit, I was able to improve the measurement accuracy by about two orders of magnitude. The GPSDO reference unit is an accuracy game changer, and now super precise frequency measurements are within reach of most hobbyists.
The ALM light is supposed to mean "Don't rely on the output frequency". The light is supposed to go off after the GPS signal has been stable for long enough that the PLL has locked and the oscillator has been tuned on frequency.
The GPS Lock light means it can decode the GPS satellite signal.
The blinking RUN light indicates that the software is working.
I've found the PLL in these do not lock exactly on frequency and they wander by millihertz. They're close enough to use as an OK frequency standard, but they're not nearly as good as they should be. That might not be a problem if you're just using it to put your VHF ham radio on frequency or using it in place of a quartz oscillator on your 1 Hz resolution frequency counter, but if you use these as a timing source the errors compound and you'll find that your time of day clock drifts significantly and randomly where using a better unit like a Trimble Thunderbolt will stay within nanoseconds day after day. I've seen mine drift over 100ns in 30 minutes. This drift is not what one expects from an atomic referenced standard.
I've found the smaller black versions of these ebay GPSDOs can still be significantly off frequency by many hertz when the ALM light first goes off.
If you're wanting this for anything serious, get a used Trimble Thunderbolt instead.
I’ve been wondering what is inside the generic Chinese GPSDOs for sale on eBay and Amazon. I guessed they are using recycled Trimble modules out of other equipment.
I’ve been using a Leo Bodnar unit as the frequency standard for my service monitor and spectrum analyzer. Bodnar states the frequency accuracy is 1/10^11. The phase noise is acceptable, but I’d have to look it up on Bodnar’s web site. I’m not generating SMPTE time codes or standardizing an NTP server, so I’ve found the Bodnar unit acceptable for a very reasonable cost.
But I forgot to add, your unboxing video is just fine, as was the rest of the video. So sayeth the retired MSEE
Oh I Love this! I first learned how to unbox things at the age of two on Christmas day...
I'm a simple man. I see a video on a GPS Disciplined Oscillator (no clue what the fuck it is) I click.
Wow, I didn't know such thing was available. It definitely has advantages to "discipline" cheaper gear that doesn't come with vcxo option
I got one something like this from Aliexpress but it's rather disappointing. On the display it just says "10.000 Mhz GPSDO" for a while then changes to say "PPB -2.3" and "PWM31077" but there are no instructions at all so I have no idea what that means. Pushing in the knob gets into a menu where I can select Contrast, Offset, PWM Set and Exit but that's all. It never displays the time like they show in some photos and there's no way to even tell if it's picking up any satellites or working at all! I opened it up and inside it has an Arduino STM32 and NEO-6M module plugged into the main board with a 5 volt regulator and LCD. The main board also has a 10.000 Mhz OSCO on it and outputs on the back for 1PPM and 10 Mhz.. With the top off I can at least see the LED blinking on the NEO-6M so I guess it's working to some extent but they should have put the LED on the front. Since there are no instructions can you tell me what PPB -2.3 and PWM31077 mean and how to use the settings for Offset, PWM Set? The PPB value goes down to just a fraction after it's been on a while so I assume that is some indication of the amount of error?
@@stevec5000 sorry, I don’t know anything more about these units than you do. Mine didn’t come with any documentation at all.
Great video, thanks!
Instant subscribe!!
Interesting bit of kit. I see they have been extensively discussed on EEVblog pages and have been around in various versions since about at least 2015. Interesting that yours has no year-month-day text marking after the BG7TBL on the front panel. Guess there are many copies of the original product with it being difficult to see if its by the original designer/producer.
Up vote for the succinct unboxing video.
If you have the opportunity measure two GPSDOs, and then have a look at the Lissajous curve! I designed a GPSDO as my thesis, I had measured it, and I think the comparison would be interesting for you as well!
@@PolyakB when I was at HP in the 1980s, we would compare the relative performance of 2 cesium beam frequency standards with a phase comparator and a strip chart recorder. It was interesting indeed. Although one might not expect any variation whatsoever between units, we could usually see some drift over time. I imagine the variation between GPSDO units is even more significant.
@@garyramsey4275 It really is! I recorded a timelapse of the two signals, triggered the scope on one of them, and they had quite a large range of phase difference.
Unboxing videos are the greatest waste of time and bandwidth.
Undisciplined unboxing videos are the greatest waste of time and bandwidth.
Very nice. How much did the GPSDO cost?
Prices vary. You can check the prices on eBay, I’m sure they’re also available from other sites too. It’s a surprisingly sophisticated piece of tech for not very much money.
If you don't mind ordering direct from China the lowest price on eBay this morning is about $70. The lowest price I see from a U.S. address is about $90. There are quite a few options in the $200 range so take your pick.
Wow!
I like how you used a PCB for the panel. Clever way to make a strong panel with text and holes for the IO components.
It wasn’t me, I didn’t make it. That’s the way these have always been made.
i have a different ver with a TRIMBLE 72345 GPSDO MODULE and the darn thing will not LOCK. I'm so disappointed what a waste of money..
Had one for years, catch up man.
All of my instruments are 40 to 60 years old. Not trying to catch up,
Crystal ovens are dinosaurs.
Some people like dinosaurs.
What did you replace them with? They are still for sale and used in many devices. The next best thing, a TCXO, is not nearly as stable, but much smaller and needs less current.
@@garyramsey4275 :)
This is a rip off. There is a cheaper 1/3 the price with LCD with a deviation value from the crystal oscillator in ppb and count. The most relible peice of gadgets that I own.
Try reading your own post before hitting enter. You might want to re type rip.
There are a plethora of Chinese GPSDOs on offer of Amazon and eBay. I suspect some of those units are using recycled Trimble boards which were originally in some other equipment. Despite the verbose listings, it is difficult to get a true sense of what you’re buying because the listings are clones of each other.
The generic GPSDO cost isn’t huge, but it isn’t zero either. I don’t feel comfortable with the no-name eBay GPSDOs. I got a Leo Bodnar Electronics GPSDO for my bench last month. The Bodnar unit is simply a programmable frequency standard with 450 Hz - 880 MHz settable output. I feel better buying the made in UK Bodnar unit because the cost is about the same and I believe Bodnar will be around if support should be needed.
@@jonka1 that was a replaced word why auto correction.
@@bayareapianist Check your reply, you might want to re type the word "why".