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ATMEGA GPS trigger voltage.
"andyfoad@..."
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 |
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Re: Heatsinking the BS170s in the U2?
"Philip"
Keith
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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 --- In QRPLabs@..., Keith Maton <nentecular@...> wrote:
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Re: Heatsinking the BS170s in the U2?
"andyfoad@..."
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 |
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Re: U2 Kit and Trimble GPS module advice required
"andyfoad@..."
As Eddie says, I'd use a decent regulator rather than a zener.
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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:
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Re: U2 Kit and Trimble GPS module advice required
Andy Cutland
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
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On 29/05/2013 15:50, Andy Cutland wrote:
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 |
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Re: U2 Kit and Trimble GPS module advice required
g3zjo
¿ªÔÆÌåÓýOn 29/05/2013 15:50, Andy Cutland wrote: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 |
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Re: Heatsinking the BS170s in the U2?
Andy Cutland
I would say no. What I have done in the past where space is tight is cut long strips of sticky copper foil the same width as the body of the fet. Seems to work ok 73's De Andy GJ7RWT From: Keith Maton To: "QRPLabs@..." Sent: Wednesday, May 29, 2013 5:34 PM Subject: [QRPLabs] Heatsinking the BS170s in the U2?
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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 |
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U2 Kit and Trimble GPS module advice required
Andy Cutland
Last night I tried hooking up the gps module to the U2 kit. Nothing happened. I had 3v going to pin 7, earth at pin 9 and 3v via a 10k resistor on pin 8 which is the pull up to take the unit out of standby. I was intending to just use the pps output for frequency control and timing so that was connected to the relevant point on the U2 kit. 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 ! I am a complete newbie at this sort of thing so any advice would be most welcome. 73's Andy GJ7RWT |
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Ultimate2 statistics
Hans Summers
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 |
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Re: U2 spotted
Andy Cutland
Thanks for posting the image Eddie, My signal looks ok, I've never really studied what a wspr signal should look like but mine seems to be able to be decoded on any band. Current status with my U2 is I'm working on trying to get the gps working. I think I may have blown it though. I will post a separate heading. Cheers 73's Andy GJ7RWT From: g3zjo To: QRPLabs@... Sent: Wednesday, May 29, 2013 9:38 AM Subject: [QRPLabs] U2 spotted
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Hi Group
I will start a folder of captures of the U2. To start it off here is GJ7RWT U2 on WSPR this morning. There could even be other U2's there, mine is shown but is merely on soak test into a dummy load, its trace is distinctive being smeary due to the band width issues and will not be on air until sorted. 73 Eddie G3ZJO |
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Re: U2 and all LPF kits finished
"dd5cf_colin"
Hi Eddie,
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Thanks for your reply I will give your idea a try. 73 Colin --- In QRPLabs@..., g3zjo <g3zjo@...> wrote:
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U2 spotted
g3zjo
Hi Group
I will start a folder of captures of the U2. To start it off here is GJ7RWT U2 on WSPR this morning. There could even be other U2's there, mine is shown but is merely on soak test into a dummy load, its trace is distinctive being smeary due to the band width issues and will not be on air until sorted. 73 Eddie G3ZJO |
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Re: U2 and all LPF kits finished
g3zjo
On 28/05/2013 21:35, dd5cf_colin wrote:
I have just finished building the LPF's and I get about 500mW on 160m up to 17m which is about 300mW and then for some reason 15m = 70mW only and 12 and 10m must below 10mW (my digital PWR meter readout does not show 1's) the BS 170's get quite hot on these 3 bandsHi Colin Instead of square waves you may be getting a low level squiggly sine wave as drive from the DDS, try adjusting the blue potentiometer on the DDS board for equal mark / space ratio on pin 7, if you don't have a scope adjust for max output on the higher frequencies. More O/P equals more efficiently running O/P stage & less heat. 73 Eddie G3ZJO |
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U2 and all LPF kits finished
"dd5cf_colin"
Hi to all members.
I have just finished building the LPF's and I get about 500mW on 160m up to 17m which is about 300mW and then for some reason 15m = 70mW only and 12 and 10m must below 10mW (my digital PWR meter readout does not show 1's) the BS 170's get quite hot on these 3 bands I have checked the 15 12 and 10m LPF's for mistakes but cant find any. I run the kit on 4 x 1.2v rechargeable AA cells and just the two BS170's that came with the kit, ideas or comments would be greatly appreciated 73 Colin DD5CF / G1ZOS |
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Re: Something else for the wish list ? (plus other thoughts)
Hans Summers
Hi Andy I'm very glad that you are enjoying yourself with the kits! Thank you for the patience while I sort out the issues. We have a lot less issues this time than with the original "Ultimate" kit (a.k.a. U1). More enhancement requests, less bugs :-) ? But the bugs are there, and they'll be all solved soon.
Gradual progress too, on the accumulation of the components for the next set of 200 U2 kits, and the components for the LF bands (475kHz LPF, 135kHz LPF). Yesterday I ordered 400 ATmega168 processors - 200 for the next round of kits, and 200 spares.?
Some delay has been caused because my supplier of the DDS modules has changed the 125MHz crystal oscillator component! The new oscillator is a surface mount kind, rather than the current large through-hole canned oscillator. For some days a stalemate existed where I have paid, but I don't accept the change (which I was notified of only after I had paid). As a compromise they are sending me one module to test to see if I like it. If it's Ok, then I'll accept the rest.?
73 Hans G0UPL On Mon, May 27, 2013 at 3:33 PM, andyfoad@... <andyfoad@...> wrote:
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Re: Something else for the wish list ? (plus other thoughts)
"andyfoad@..."
Hi Hans,
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Well I suppose if it's possible then that would be a nice addition, but I'm sure you have better priorities in life ;-) At this point I'd like to thank you for all the work you have put in to these little kits. I've been so busy playing with the U1 and U2 the last 6 month that I've probably not mentioned my gratitude, or spoken very much to the XYL - because of all the time I've devoted to building these little gems ! I am surprised that there is not much written in any major publications about QRSS and these odd modes. Perhaps we really are a minority with our experiments. I've been quite taken by both WSPR and QRSS of late and learnt a lot. I think QRSS is often seen as poor relation to WSPR, but where else can you see what looks like a chart recorder of yours and other signals to compare them by. WSPR doesn't make it easy to compare the performance of other stations without a lot of to'ing and throwing about on the WSPR d/base. QRSS grabbers fit the bill nicely and show up all sorts of other effects that WSPR could never do. Multipath distortion, ionospheric oddities, auroras etc. And then there is on the grabber traces what I call "ionospheric bend". Not bending the ionosphere but the bend in the grabber trace which you see on a stable TX when the ionosphere is changing height and shifts the incoming signal frequency by about 1Hz. I see this often on the W4HBK grabber on my signals on 10Mhz. Fascinating stuff, and I think there is more to come. 73 de Andy G0FTD --- In QRPLabs@..., Hans Summers <hans.summers@...> wrote:
Ok well I think I have space for it. |
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