Re: GPS behaviour very inconsistent

Tony Volpe

Good news Barry. Delighted your new GPS works with the new kit.?

However, there is nothing wrong with the EM-406A. I've had one working with the UQRSS1 for about ten months, day in day out 24/7. It is working now with all GPS functions working correctly as designed. However, it behaves just like yours did on the UQ2.

The issue with the UQRSS2 is being caused by some different way the software in this kit works. It's a shame really, but I won't be spending another ?17 to replace a GPS that is not faulty.

Best regards

Tony G0BZB

Show quoted text

On 31 May 2013 12:18, Barry Chambers <b.chambers@...> wrote:

Afternoon All

For several weeks, I've been struggling to get my U2 kit working with a
EM-406A GPS module. The problem seems to be with the 1pps signal. as the
NEMA data is read correctly.

Today, I got through the post a Fastrax (Reyax) ?UP501 GPS module (from
Taiwan via E-Bay, ?17, about 10 days delivery time). Hans lists this
module on the U2 kit web pages. It requires a 3.3v supply and the modem
setting is 09600,10,1,8. Hey presto! ?It works! I found that the "Inv
GPS" setting needs to be "On". The clock keeps perfect time (as compared
against my wireless clock), the Locator is set correctly and the DDS
125MHz oscillator frequency is corrected (mine is now slightly lower
than 125 MHz). At present I have "Start" set at 02 and "Frame" at 04 and
the U2 is on soak test on 20m WSPR with a "loop" made from two pieces of
wire about 15cm long, joined by a 47R resistor.

73

Barry, G8AGN

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U1 kit - low Freq

"Chris D"

#1261

Finally got around to fixing my dead U1 kit. Seems to be working fine except for low freq. Did the C4,5 cap change to 18pF from 22pF. Didn't seem to move it much. Highest I can get it is 10139.5  Will try 15pF.  Anyone else have much trouble pushing it up to where it should be?

72,
Chris
KQ2RP

Re: GPS behaviour very inconsistent

Barry Chambers

#1260

Afternoon All

For several weeks, I've been struggling to get my U2 kit working with a EM-406A GPS module. The problem seems to be with the 1pps signal. as the NEMA data is read correctly.

Today, I got through the post a Fastrax (Reyax)  UP501 GPS module (from Taiwan via E-Bay, ???17, about 10 days delivery time). Hans lists this module on the U2 kit web pages. It requires a 3.3v supply and the modem setting is 09600,10,1,8. Hey presto!  It works! I found that the "Inv GPS" setting needs to be "On". The clock keeps perfect time (as compared against my wireless clock), the Locator is set correctly and the DDS 125MHz oscillator frequency is corrected (mine is now slightly lower than 125 MHz). At present I have "Start" set at 02 and "Frame" at 04 and the U2 is on soak test on 20m WSPR with a "loop" made from two pieces of wire about 15cm long, joined by a 47R resistor.

73

Barry, G8AGN

Re: U2 and automatic frequency stabilisation

Tony Volpe

#1259

I ran my UQ1 in a shabby poystyrene box 24/7 for ten months on 10.140 and it sat there like a rock. Looked rubbish; was rubbish, but it did a good job.

:))

Show quoted text

On 31 May 2013 09:38, Keith Maton <nentecular@...> wrote:

?

Thanks Hans.

It seems that although my new boxed unit is very pretty, it's rubbish as an oven as it drifted all over the place last night as the shack cooled down.

73 Keith.

On 30 May 2013, at 23:30, Hans Summers <hans.summers@...> wrote:

?

Hi Keith

I'll check it ASAP!

The weekend is coming up! Just one more day! Means being able to stop wasting time in the office, and spend it worthily in the radio room (and with XYL).?

73 Hans G0UPL

On Thu, May 30, 2013 at 11:09 PM, Keith Maton <nentecular@...> wrote:

?

All (specifically Hans),

I've found what I think is a problem with the frequency stabilisation routine in the U2.

The manual says:

"When using the connected GPS module for frequency stabilisation, you must choose a non-zero Frame parameter. This is because the frequency stabilisation must take place when there is no transmission from the kit, i.e. during a pause between transmissions. The frequency stabilisation takes 12 seconds and occurs just before the start of a transmission. Therefore you need to ensure that the Frame parameter is sufficiently large that there is a minimum gap of 12 seconds between the completion of your message transmission and the start of the next one."

This is all great in WSPR because there is a period of non transmission between each frame but it's not possible to do this when running FSKCW (and probably other QRSS modes, I've not checked them all).

I have my kit all working well and when I first start it, the frequency is absolutely spot on because it's calibrated. However, when starting from cold, there's always an initial drift as it all warms up.

My callsign takes 9 minutes and 40 seconds to send, leaving a period of 20 seconds or so before the next frame starts but the kit continues to transmit the lower tone for those 20 seconds and so it doesn't calibrate.

With the kit built into a box which works well as an oven, I've just watched it start transmitting on the correct frequency and then drift 20Hz upwards. When the next frame started, it carried on drifting so I simply cycled through all the menus and after the next frame had completed, I pushed the right button and when it started transmitting a few seconds later, it had run the stabilisation and was back on the correct frequency. It still hadn't reached the stable temperature in the box so it continued to drift upwards.

So as it stands, when running FSKCW (and possibly other modes), there's no stabilisation apart from the initial routine, no matter how long the callsign is because there isn't a pause between transmissions.

I don't think the transmitter should be switched off between frames because that will cause a temperature change of the overall unit, especially if it's built into a sealed enclosure and it will drift again once the transmitter comes back on.

I think a fix would be to force the transmitter off automatically for fifteen seconds prior to the end of the frame to allow stabilisation to take place.

Has anyone else noticed this?

I've uploaded a screenshot of what happens when I cycle through the menus at the end of the frame here - You can see that it's dropped back down to the correct frequency but I'll need to do it again at the end of this cycle as it's still not quite warmed up fully yet.

The automatic stabilisation routine is fantastic but it needs to work every frame to be worthwhile.

Or have I got something wrong in the menus that's stopping this from working? I have my frame length set to 10 and the start set to 1.

73, Keith.

Re: U2 and automatic frequency stabilisation

Keith Maton

#1258

开云体育

Thanks Hans.

It seems that although my new boxed unit is very pretty, it's rubbish as an oven as it drifted all over the place last night as the shack cooled down.

73 Keith.

Show quoted text

On 30 May 2013, at 23:30, Hans Summers <hans.summers@...> wrote:

?

Hi Keith

I'll check it ASAP!

The weekend is coming up! Just one more day! Means being able to stop wasting time in the office, and spend it worthily in the radio room (and with XYL).?

73 Hans G0UPL

On Thu, May 30, 2013 at 11:09 PM, Keith Maton <[email protected]> wrote:

?

All (specifically Hans),

I've found what I think is a problem with the frequency stabilisation routine in the U2.

The manual says:

"When using the connected GPS module for frequency stabilisation, you must choose a non-zero Frame parameter. This is because the frequency stabilisation must take place when there is no transmission from the kit, i.e. during a pause between transmissions. The frequency stabilisation takes 12 seconds and occurs just before the start of a transmission. Therefore you need to ensure that the Frame parameter is sufficiently large that there is a minimum gap of 12 seconds between the completion of your message transmission and the start of the next one."

This is all great in WSPR because there is a period of non transmission between each frame but it's not possible to do this when running FSKCW (and probably other QRSS modes, I've not checked them all).

I have my kit all working well and when I first start it, the frequency is absolutely spot on because it's calibrated. However, when starting from cold, there's always an initial drift as it all warms up.

My callsign takes 9 minutes and 40 seconds to send, leaving a period of 20 seconds or so before the next frame starts but the kit continues to transmit the lower tone for those 20 seconds and so it doesn't calibrate.

With the kit built into a box which works well as an oven, I've just watched it start transmitting on the correct frequency and then drift 20Hz upwards. When the next frame started, it carried on drifting so I simply cycled through all the menus and after the next frame had completed, I pushed the right button and when it started transmitting a few seconds later, it had run the stabilisation and was back on the correct frequency. It still hadn't reached the stable temperature in the box so it continued to drift upwards.

So as it stands, when running FSKCW (and possibly other modes), there's no stabilisation apart from the initial routine, no matter how long the callsign is because there isn't a pause between transmissions.

I don't think the transmitter should be switched off between frames because that will cause a temperature change of the overall unit, especially if it's built into a sealed enclosure and it will drift again once the transmitter comes back on.

I think a fix would be to force the transmitter off automatically for fifteen seconds prior to the end of the frame to allow stabilisation to take place.

Has anyone else noticed this?

I've uploaded a screenshot of what happens when I cycle through the menus at the end of the frame here - You can see that it's dropped back down to the correct frequency but I'll need to do it again at the end of this cycle as it's still not quite warmed up fully yet.

The automatic stabilisation routine is fantastic but it needs to work every frame to be worthwhile.

Or have I got something wrong in the menus that's stopping this from working? I have my frame length set to 10 and the start set to 1.

73, Keith.

Re: Ultimate2 statistics

Michael O'Bannon

#1275

开云体育

Hans,

I grew curious as to why two shipments of Ultimate kits might show a difference of more than a month in delivery time to the US.??? So I retrieved both packages from the basement and compared them.??? The faster package is marked "Small Packet" and has a return address.??? The slower package has neither.??? The faster package is also declared for 3 gram heavier weight than the slower one.

I can only speculate that the lack of return address or perhaps underdeclared weight may have routed the slower package for more scrutiny before delivery.

73,
Michael??? KD4SGN

Show quoted text

Hi Michael

Your order 1050 of two U2 kits (20m and 30m) was shipped on 30-Apr-2013, it was in the first batch to be shipped. If it does not turn up, I will have another sent to you. However the kits are still in preparation stage, none are available to ship yet.???

It certainly seems like a very long shipping time. However, I went back through my records and found that the same thing happened to you before!???

You ordered an Ultimate kit (U1) on 11-July-2012. We started having correspondence about it going missing, on 11-August-2012. At that time Steve G0XAR was shipping, from the UK. He sent you a replacement kit on 13-August-2012. You reported that both the replacement kit, AND the original one, turned up together on 21-August-2012 on the same day.???

So in that case it appears that UK to US shipping of your first Ultimate kit took 6 weeks (the replacement taking only 1 week). That kind of delay appears very rare and it seems a big coincidence that it has happened to you twice now. So I wonder if there is something particular/peculiar about your local customs office or post office. Very strange.

In any event the prior experience seems to suggest that we should wait a bit longer. Anyway, we have no choice in the matter, since there are currently no U2 kits to be able to ship a replacement yet anyway.

Fingers crossed, I hope it turns up soon.

73 Hans G0UPL

On Fri, May 31, 2013 at 11:05 PM, Michael O'Bannon <mob@...> wrote:

???

Hans,

From your spreadsheet, I see that the average number of shipping days to the US is 6.6.??? I ordered my kit on April 20, and it still has not arrived.??? If it was one of the first 200, my data will cause a considerable skew to your statistics.

Could you tell me whether the kit has been shipped yet?

Best regards,
Michael??? KD4SGN

Hi all

I finally got round to typing all my order details into a big spreadsheet and doing some statistics. From time to time I'll update the charts.

1) The number of LPF kits that have been ordered so far, total 637. Remember, not all of these have been sent out - there are 48 Ultimate2 orders currently pending since the first set of 200 sold out and I am getting the new set together. So the numbers in the chart includes the sent and the unsent orders.

2) The shipping information. Thank you to everybody who wrote to told me when their kit arrived, I have compiled all this information and arranged it into a table, by country - so that you can see the minimum, average, and maximum shipping times to your country.

See???

73 Hans G0UPL

Re: Ultimate2 statistics

Michael O'Bannon

#1274

开云体育

Hans,

Yes, your records are correct.??? It does seem strange, particularly because I usually receive one or two packages of electronic parts from out of the country each month.??? The previous Ultimate kit and this one are the only unusual delays I've seen in several years.??? Even packages from China always show up in two to three weeks.??? Looks as if your maximum shipping time to the US is going to be 40+ days.

73,
Michael??? KD4SGN
???

Show quoted text

You ordered an Ultimate kit (U1) on 11-July-2012. We started having correspondence about it going missing, on 11-August-2012. At that time Steve G0XAR was shipping, from the UK. He sent you a replacement kit on 13-August-2012. You reported that both the replacement kit, AND the original one, turned up together on 21-August-2012 on the same day.???

So in that case it appears that UK to US shipping of your first Ultimate kit took 6 weeks (the replacement taking only 1 week). That kind of delay appears very rare and it seems a big coincidence that it has happened to you twice now. So I wonder if there is something particular/peculiar about your local customs office or post office. Very strange.

In any event the prior experience seems to suggest that we should wait a bit longer. Anyway, we have no choice in the matter, since there are currently no U2 kits to be able to ship a replacement yet anyway.

Fingers crossed, I hope it turns up soon.

73 Hans G0UPL

On Fri, May 31, 2013 at 11:05 PM, Michael O'Bannon <mob@...> wrote:

???

Hans,

From your spreadsheet, I see that the average number of shipping days to the US is 6.6.??? I ordered my kit on April 20, and it still has not arrived.??? If it was one of the first 200, my data will cause a considerable skew to your statistics.

Could you tell me whether the kit has been shipped yet?

Best regards,
Michael??? KD4SGN

Hi all

I finally got round to typing all my order details into a big spreadsheet and doing some statistics. From time to time I'll update the charts.

1) The number of LPF kits that have been ordered so far, total 637. Remember, not all of these have been sent out - there are 48 Ultimate2 orders currently pending since the first set of 200 sold out and I am getting the new set together. So the numbers in the chart includes the sent and the unsent orders.

2) The shipping information. Thank you to everybody who wrote to told me when their kit arrived, I have compiled all this information and arranged it into a table, by country - so that you can see the minimum, average, and maximum shipping times to your country.

See???

73 Hans G0UPL

Re: Problem with U2 after boxing

arv

#1257

开云体育

Claustrophobia...?

On 05/30/2013 03:45 PM, Hans Summers wrote:

Show quoted text

???

Hi Keith

I'm glad it's working Ok.

If I had a pound for every time a project worked fine outside the box, and stopped working when I boxed it all up neatly. Actually it happened with my "Ultimate" a.k.a. U1. Worked fine until I put it in the box. But then: not even any display on the LCD! Then I got distracted, working on the U2... so I still don't know what happened to it!???

73 Hans G0UPL

On Thu, May 30, 2013 at 5:35 PM, Keith Maton <nentecular@...> wrote:

???

Belay that.

I've simply restarted it again in FSKCW mode and it seems to be working.

To say I don't understand this would be an understatement.

73 Keith.

On 30 May 2013, at 16:45, Keith Maton <nentecular@...> wrote:

???

Right then.

My U2 has been working well for over a week so today I decided to do the boxing up thing.

After three hours of plastic panel bashing, screwing, fixing and soldering (far more time than it took to build the actual unit) I was ready to go.

Switched on and all I get is a single continuous tone. Even in normal CW mode that's it, just a tone at full power (over 0.5W on 40m with 4 x BS170s). The logic is clearly working OK because I have full control.

I've checked and double checked everything and all connections look good with no shorts or open circuits anywhere.

The only thing different is that I've connected two external switches and not removed the original two.

I can go through the menus and change the configuration with no problems and I even tried a button-down factory reset.

It looks great in the box and it'll provide a fantastic oven to keep the temperature stable but the down side is that it just doesn't work!

Has anyone experienced this same problem at all?

73 Keith, G6NHU

Re: U2 and automatic frequency stabilisation

Hans Summers

#1256

Hi Keith

I'll check it ASAP!

The weekend is coming up! Just one more day! Means being able to stop wasting time in the office, and spend it worthily in the radio room (and with XYL).?

73 Hans G0UPL

Show quoted text

On Thu, May 30, 2013 at 11:09 PM, Keith Maton <nentecular@...> wrote:

?

All (specifically Hans),

I've found what I think is a problem with the frequency stabilisation routine in the U2.

The manual says:

"When using the connected GPS module for frequency stabilisation, you must choose a non-zero Frame parameter. This is because the frequency stabilisation must take place when there is no transmission from the kit, i.e. during a pause between transmissions. The frequency stabilisation takes 12 seconds and occurs just before the start of a transmission. Therefore you need to ensure that the Frame parameter is sufficiently large that there is a minimum gap of 12 seconds between the completion of your message transmission and the start of the next one."

This is all great in WSPR because there is a period of non transmission between each frame but it's not possible to do this when running FSKCW (and probably other QRSS modes, I've not checked them all).

I have my kit all working well and when I first start it, the frequency is absolutely spot on because it's calibrated. However, when starting from cold, there's always an initial drift as it all warms up.

My callsign takes 9 minutes and 40 seconds to send, leaving a period of 20 seconds or so before the next frame starts but the kit continues to transmit the lower tone for those 20 seconds and so it doesn't calibrate.

With the kit built into a box which works well as an oven, I've just watched it start transmitting on the correct frequency and then drift 20Hz upwards. When the next frame started, it carried on drifting so I simply cycled through all the menus and after the next frame had completed, I pushed the right button and when it started transmitting a few seconds later, it had run the stabilisation and was back on the correct frequency. It still hadn't reached the stable temperature in the box so it continued to drift upwards.

So as it stands, when running FSKCW (and possibly other modes), there's no stabilisation apart from the initial routine, no matter how long the callsign is because there isn't a pause between transmissions.

I don't think the transmitter should be switched off between frames because that will cause a temperature change of the overall unit, especially if it's built into a sealed enclosure and it will drift again once the transmitter comes back on.

I think a fix would be to force the transmitter off automatically for fifteen seconds prior to the end of the frame to allow stabilisation to take place.

Has anyone else noticed this?

I've uploaded a screenshot of what happens when I cycle through the menus at the end of the frame here - You can see that it's dropped back down to the correct frequency but I'll need to do it again at the end of this cycle as it's still not quite warmed up fully yet.

The automatic stabilisation routine is fantastic but it needs to work every frame to be worthwhile.

Or have I got something wrong in the menus that's stopping this from working? I have my frame length set to 10 and the start set to 1.

73, Keith.

U2 and automatic frequency stabilisation

Keith Maton

#1255

All (specifically Hans),

I've found what I think is a problem with the frequency stabilisation routine in the U2.

The manual says:

"When using the connected GPS module for frequency stabilisation, you must choose a non-zero Frame parameter. This is because the frequency stabilisation must take place when there is no transmission from the kit, i.e. during a pause between transmissions. The frequency stabilisation takes 12 seconds and occurs just before the start of a transmission. Therefore you need to ensure that the Frame parameter is sufficiently large that there is a minimum gap of 12 seconds between the completion of your message transmission and the start of the next one."

This is all great in WSPR because there is a period of non transmission between each frame but it's not possible to do this when running FSKCW (and probably other QRSS modes, I've not checked them all).

I have my kit all working well and when I first start it, the frequency is absolutely spot on because it's calibrated.  However, when starting from cold, there's always an initial drift as it all warms up.

My callsign takes 9 minutes and 40 seconds to send, leaving a period of 20 seconds or so before the next frame starts but the kit continues to transmit the lower tone for those 20 seconds and so it doesn't calibrate.

With the kit built into a box which works well as an oven, I've just watched it start transmitting on the correct frequency and then drift 20Hz upwards.  When the next frame started, it carried on drifting so I simply cycled through all the menus and after the next frame had completed, I pushed the right button and when it started transmitting a few seconds later, it had run the stabilisation and was back on the correct frequency.  It still hadn't reached the stable temperature in the box so it continued to drift upwards.

So as it stands, when running FSKCW (and possibly other modes), there's no stabilisation apart from the initial routine, no matter how long the callsign is because there isn't a pause between transmissions.

I don't think the transmitter should be switched off between frames because that will cause a temperature change of the overall unit, especially if it's built into a sealed enclosure and it will drift again once the transmitter comes back on.

I think a fix would be to force the transmitter off automatically for fifteen seconds prior to the end of the frame to allow stabilisation to take place.

Has anyone else noticed this?

I've uploaded a screenshot of what happens when I cycle through the menus at the end of the frame here - You can see that it's dropped back down to the correct frequency but I'll need to do it again at the end of this cycle as it's still not quite warmed up fully yet.  

The automatic stabilisation routine is fantastic but it needs to work every frame to be worthwhile.

Or have I got something wrong in the menus that's stopping this from working?  I have my frame length set to 10 and the start set to 1.

73, Keith.

Re: Problem with U2 after boxing

Hans Summers

#1254

Hi Keith

I'm glad it's working Ok.

If I had a pound for every time a project worked fine outside the box, and stopped working when I boxed it all up neatly. Actually it happened with my "Ultimate" a.k.a. U1. Worked fine until I put it in the box. But then: not even any display on the LCD! Then I got distracted, working on the U2... so I still don't know what happened to it!?

73 Hans G0UPL

Show quoted text

On Thu, May 30, 2013 at 5:35 PM, Keith Maton <nentecular@...> wrote:

?

Belay that.

I've simply restarted it again in FSKCW mode and it seems to be working.

To say I don't understand this would be an understatement.

73 Keith.

On 30 May 2013, at 16:45, Keith Maton <nentecular@...> wrote:

?
Right then.

My U2 has been working well for over a week so today I decided to do the boxing up thing.

After three hours of plastic panel bashing, screwing, fixing and soldering (far more time than it took to build the actual unit) I was ready to go.

Switched on and all I get is a single continuous tone. Even in normal CW mode that's it, just a tone at full power (over 0.5W on 40m with 4 x BS170s). The logic is clearly working OK because I have full control.

I've checked and double checked everything and all connections look good with no shorts or open circuits anywhere.

The only thing different is that I've connected two external switches and not removed the original two.

I can go through the menus and change the configuration with no problems and I even tried a button-down factory reset.

It looks great in the box and it'll provide a fantastic oven to keep the temperature stable but the down side is that it just doesn't work!

Has anyone experienced this same problem at all?

73 Keith, G6NHU

Re: Problem with U2 after boxing

Keith Maton

#1253

开云体育

Belay that.

I've simply restarted it again in FSKCW mode and it seems to be working.

To say I don't understand this would be an understatement.

73 Keith.

Show quoted text

On 30 May 2013, at 16:45, Keith Maton <nentecular@...> wrote:

?
Right then.

My U2 has been working well for over a week so today I decided to do the boxing up thing.

After three hours of plastic panel bashing, screwing, fixing and soldering (far more time than it took to build the actual unit) I was ready to go.

Switched on and all I get is a single continuous tone. Even in normal CW mode that's it, just a tone at full power (over 0.5W on 40m with 4 x BS170s). The logic is clearly working OK because I have full control.

I've checked and double checked everything and all connections look good with no shorts or open circuits anywhere.

The only thing different is that I've connected two external switches and not removed the original two.

I can go through the menus and change the configuration with no problems and I even tried a button-down factory reset.

It looks great in the box and it'll provide a fantastic oven to keep the temperature stable but the down side is that it just doesn't work!

Has anyone experienced this same problem at all?

73 Keith, G6NHU

Problem with U2 after boxing

Keith Maton

#1252

Right then.

My U2 has been working well for over a week so today I decided to do the boxing up thing.

After three hours of plastic panel bashing, screwing, fixing and soldering (far more time than it took to build the actual unit) I was ready to go.

Switched on and all I get is a single continuous tone.  Even in normal CW mode that's it, just a tone at full power (over 0.5W on 40m with 4 x BS170s).  The logic is clearly working OK because I have full control.

I've checked and double checked everything and all connections look good with no shorts or open circuits anywhere.

The only thing different is that I've connected two external switches and not removed the original two.

I can go through the menus and change the configuration with no problems and I even tried a button-down factory reset.

It looks great in the box and it'll provide a fantastic oven to keep the temperature stable but the down side is that it just doesn't work!

Has anyone experienced this same problem at all?

73 Keith, G6NHU

Re: U2 Kit and Trimble GPS module advice required

Andy Cutland

#1251

Thanks to all who sent advice. I am ordering some 3.3 regs today. Didn't get any shack tine last night so I have nothing to report back tight now. Will let you know how I get on. 

73's
Andy

------------------------------

Show quoted text

On Wed, May 29, 2013 10:29 AM PDT andyfoad@... wrote:

As Eddie says, I'd use a decent regulator rather than a zener.

Also what are you measuring the 1pps signal with ?

A DMM might not have the response time to show it properly,
especially if it's a very narrow width pulse.

An analogue meter would help, but a scope is better.

Or, just to test it, an LED and a 1K resistor and it should pulse.

73 de Andy FTD

--- In QRPLabs@..., Andy Cutland <gj7rwt@...> wrote:

Hi Eddie,

I originally got my 3v from using a few diodes in series off the 5v reg pin. When this appeared not to work I then tried a pot but I may have limited the current too much with the output resistor so I need to experiment again tonight.

I was really confused at this low voltage reading on pin 7. Will check again tonight and see what results I get.

Thanks for the advice.

73's
Andy

ATMEGA GPS trigger voltage.

"andyfoad@..."

#1250

Not sure if this is of any use but I've just measured the 1PPS output
of my Reyax UP501 GPS module on a 'scope, 2.8v. (Module runs on 3.3v).

I know that this reliably triggers the ATMEGA enough for it to work
with the signal.

But I know that if put a current limiting resistor in series then
it will  not work at all (a 2K2).

Trying to measure the pulse on a DMM or even an analogue meter
will show about 0.7v due tho the rise time restriction of such
meters.

73 de Andy G0FTD

Re: Heatsinking the BS170s in the U2?

"Philip"

#1249

Keith

Break a 20mm fuse and clean the glass and gunk out of the metal end caps
These end caps are a perfect snug fit on the BS170 body.

Before pushing on, solder a bit of brass or copper to the end caps
to make some mass to sink the heat.
You can see mine in this picture (a curly piece of copper soldered to a cap)

Works a treat (break the fuse in a bag to save your eyes)

Philip  G4JVF

Show quoted text

--- In QRPLabs@..., Keith Maton <nentecular@...> wrote:

I've got four BS170s fitted to my U2 kit and will be getting it boxed up in the next few days.

Is there enough physical space there to fit four of these clip on heatsinks?

73 Keith, G6NHU

Re: Heatsinking the BS170s in the U2?

"andyfoad@..."

#1248

1)You would probably be able to get away with not heatsinking it.
Mine is running 9v with 100% duty cycle. Runs hot but no harm so far.

or

2)If you have left a reasonable lead length on the BS170's then
you can use these style heatsinks and just give the BS170's a little
twist and bend over to fit the alternative heatsinks in the link below.

They don't take so much space.

Link sends you to RS.

Hope this helps.

73 de Andy G0FTD

Re: U2 Kit and Trimble GPS module advice required

"andyfoad@..."

#1247

As Eddie says, I'd use a decent regulator rather than a zener.

Also what are you measuring the 1pps signal with ?

A DMM might not have the response time to show it properly,
especially if it's a very narrow width pulse.

An analogue meter would help, but a scope is better.

Or, just to test it, an LED and a 1K resistor and it should pulse.

73 de Andy FTD

Show quoted text

--- In QRPLabs@..., Andy Cutland <gj7rwt@...> wrote:

Hi Eddie,

I originally got my 3v from using a few diodes in series off the 5v reg pin. When this appeared not to work I then tried a pot but I may have limited the current too much with the output resistor so I need to experiment again tonight.

I was really confused at this low voltage reading on pin 7. Will check again tonight and see what results I get.

Thanks for the advice.

73's
Andy

Re: U2 Kit and Trimble GPS module advice required

g3zjo

#1246

On 29/05/2013 18:09, Andy Cutland wrote:
I originally got my 3v from using a few diodes in series off the 5v reg pin. Hmm, get a 3v3 Regulator.:-)

Eddie

Re: U2 Kit and Trimble GPS module advice required

Andy Cutland

#1245

Hi Eddie,

I originally got my 3v from using a few diodes in series off the 5v reg pin. When this appeared not to work I then tried a pot but I may have limited the current too much with the output resistor so I need to experiment again tonight.

I was really confused at this low voltage reading on pin 7. Will check again tonight and see what results I get.

Thanks for the advice.

73's
Andy

From: g3zjo
To: QRPLabs@...
Sent: Wednesday, May 29, 2013 5:58 PM
Subject: Re: [QRPLabs] U2 Kit and Trimble GPS module advice required

On 29/05/2013 15:50, Andy Cutland wrote:

The U2 refused to update the time so I thought something was wrong with my gps connections. I measured the voltage at pin 7 which showed 0.79v with a similar voltage showing on pin 8. Does this sound correct. I couldn't detect anything on the pps output pin (not sure what settings i need on the scope for this). I am going to take another look at it tonight with fresh eyes and a clearer head !

Andy

Something is wrong re pin7 showing? 0.79v. you have applied your 3v supply and here and you would expect to see that value, likewise with pin 8 the 10k should pull it up to the supply voltage.
How have you derived your 3v supply.
Is there a short somewhere in connecting up. Hopefully the GPS Module is not pulling down the supply.

When you get the voltages right why not connect the Data also, this will update the clock to real time and is easily visible on a scope and the result is visible on the U2 nicely.
The PPS out I could no see on my scope the only detection of its presence was by setting the scope to trigger on its leading edge. Bear in mind that the PPS needs a 3D lock and hence a good view of the satellites, the results on the U2 always come later than the real time update.

73 Eddie G3ZJO