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Re: GPS behaviour very inconsistent
"David Atkins"
¿ªÔÆÌåÓýMy thanks to Tony and Phil for publishing pictures of their
builds, and to everyone else, like Keith,?who has given details of their
construction. All of your experiences are helping me plan my own
installation.
?
?
Both of my units are currently languishing in a drawer,
pending Hans' return and his words of wisdom. The U2's USP for me was that it
could be portable and self-contained. I wanted the ability to set up a WSPR
beacon in the middle of nowhere without having to take a load of other
equipment. The U2 should work out its location, sort out its clock to WSPR
standards, and start to talk. Mine have both got the location sorted, but the
lack of pps functionality means that neither the location nor the timing are
usable. I'm confident that we shall see a solution soon. Sadly, I have a trip to
the Highlands on Wednesday that will most likely be too premature for
that.
In the meantime, I have shack-bound WSPR capabilities that
I can go back to using. But I was so looking forward to being portable
;-(
?
A naive question. What did the Beta-testers use that gave
them success? Is there a way I can copy that?
?
Best Wishes
?
David G8XBZ
From:
QRPLabs@... [mailto:QRPLabs@...] On Behalf Of
Keith Maton
I
have one further update regarding the initial time setting from the GPS using
the Adafruit.
Sent: 26 May 2013 10:39 To: QRPLabs@... Subject: Re: [QRPLabs] GPS behaviour very inconsistent If it's all powered off and I start the GPS and the U2 at the same time,
the U2 will give a slightly incorrect time depending on how long it takes the
GPS to lock.
So if the GPS takes six seconds to find a lock the time displayed by the U2
will be six seconds slow.
Simply inverting and re-inverting the GPS settings cause that error to be
corrected.
I hope this is helpful.
73 Keith, G6NHU
? |
Re: GPS behaviour very inconsistent
Keith Maton
¿ªÔÆÌåÓýI have one further update regarding the initial time setting from the GPS using the Adafruit.If it's all powered off and I start the GPS and the U2 at the same time, the U2 will give a slightly incorrect time depending on how long it takes the GPS to lock. So if the GPS takes six seconds to find a lock the time displayed by the U2 will be six seconds slow. Simply inverting and re-inverting the GPS settings cause that error to be corrected. I hope this is helpful. 73 Keith, G6NHU On 21 May 2013, at 11:34, Keith Maton <nentecular@...> wrote:
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Re: U2 photos.
"andyfoad@..."
--- In QRPLabs@..., g3zjo <g3zjo@...> wrote:
Same here. Have done for many years. More hassle than it's worth with RF about. In my case connecting the 'safetyAnyone for PME ? ;-) Regards to all, Andy |
Re: U2 photos.
g3zjo
¿ªÔÆÌåÓýAlanThat's a whole can of worms you have opened. I would do the same or similar, I run in a Mains Earth free environment. I am sure Andy knows what he is doing. In my case connecting the 'safety earth' would mean I was connecting? my antenna system to the Neutral of the mains supply and also directly to the Neutral of the next door house. Under fault conditions (which did happen here) the chassis of the U2 could then rise to phase potential and huge current would sink to Earth via the antenna system or via the operator. 73 Eddie G3ZJO ? On 25/05/2013 13:58, Alan wrote: ? |
Re: U2 photos.
"Alan"
I assume that's an incoming 240V mains cable feeding the transformer. It looks as if you've chopped the earth wire adjacent to the end of the outer jacket. As it's a metal box, it needs the safety earth connecting. We'd hate to lose you...
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Regards, Alan G0RWB --- In QRPLabs@..., "andyfoad@..." <andyfoad@...> wrote:
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Re: U2 photos.
"Philip"
Nicely done Andy....
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Philip G4JVF --- In QRPLabs@..., "andyfoad@..." <andyfoad@...> wrote:
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Re: U2 Erratic Timing - some detail
"TONY_VOLPE"
--- In QRPLabs@..., Barry Chambers <b.chambers@...> wrote:
Me too. My EM-406A is the same. |
Re: U2 Erratic Timing - some detail
Barry Chambers
¿ªÔÆÌåÓýOn 23/05/2013 21:50, David Atkins
wrote:
?David Your GPS experiences pretty well match mine, except that I'm using a EM-406A GPS. -- 73 Barry, G8AGN |
U2 Erratic Timing - some detail
"David Atkins"
I hope the detailed description of the erratic behaviour, recorded below,
will give an indication to someone of the cause. My Trimble Jupiter modules refused to register [both of them]. So did my Sure Evaluation kit. Even though they all work perfectly with several GPS evaluation programmes. An EM-406a arrived from Germany this morning, and I have tried everything I have seen suggested in the past week or so. This is how it goes: I have Frame set to 10 I have Start set to 04 GPS Baud is 04800,01,1,8 Use GPS On Inv GPS On -- yes, I know, but nothing works with it off Frq set to 10.140.198 Locator is rubbish Set Time is rubbish Switch on at 16:00:04 Locator sets correctly to IO91, time sets correctly to 16:00:04, Sys Frq remains un-modified; Time them increments in two-second steps every second -- 06, 08, 10, etc -- until it reads 16:03:50, when it resets itself to the correct time (16:01:26, say). Then count up at double speed until it gets to 16:03:50, when it resets itself to the correct time, and starts counting up at double speed again. This happens over and over until the time really is 16:03:50, when it counts on up to 16:04:00 and starts transmitting. Of course, it counted at double speed, so the transmission starts at about 3 seconds before the start of the even minute. But the transmission itself is at normal speed, so I can decode it on another rig. After the transmission, we go through the double speed until the clock reads 16:13:50, then the reset etc cycle goes on until the transmission at a couple of seconds before 16:14:00. Does that seem reasonable? OK, so how do I cure it? I have the RX data pin of the module tied to Vcc, and both ground pins are connected to 0v. Beyond that, I have tried pull-up resistors (10k ohm) and pull-down resistors on the pps line and/or the TX data line. No change. ?help? David G8XBZ |
U2 gets an outing on 40m.
"andyfoad@..."
Played FSKCW and Slow Hell on 40m earlier, works very well and
watched the quality of my signals on a couple of grabbers. I'm pleased to report that despite being run with no heatsinks for hours on end all three PA FETS are quite happily chugging away with no problems despite running hot at 9 volts ;-) Still need to box the dratted thing as time allows... 73 da 'FTD |
Re: Some better news U2
"Philip"
Eddie
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What type of antenna are you using on 474? Philip G4JVF --- In QRPLabs@..., g3zjo <g3zjo@...> wrote:
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Re: Some better news U2
"andyfoad@..."
Thanks !
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--- In QRPLabs@..., g3zjo <g3zjo@...> wrote:
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Re: Ultimate2 kit status summary
"andyfoad@..."
Same problem as I noticed and mentioned in an earlier post.
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At first I thought that when I had the 28Mhz PA problem that I might have caused some damage to the ATMEGA. 73 de Andy --- In QRPLabs@..., Keith Maton <nentecular@...> wrote:
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Re: Ultimate2 kit status summary
Keith Maton
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On 22 May 2013, at 22:37, Hans Summers <hans.summers@...> wrote:
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Re: Some better news U2
Barry Chambers
¿ªÔÆÌåÓýOn 23/05/2013 11:47, g3zjo wrote:
?Eddie the Dx is 129km - still getting good decodes. -- 73 Barry, G8AGN |