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Re: Any BPF 50 MHz design
Hans Summers
All If someone builds a 6m design, 7-element LPF which will fit on the kit PCB, I am happy to stock them in the shop. I think it would be good if someone proves it works first ;-)
One free Ultimate2 kit (or other kits of equivalent value) to whoever proves the U2 works on 6m, and has reception reports to prove it! 73 Hans G0UPL On Mon, Jun 17, 2013 at 5:55 PM, Paul KE7HR <ke7hr@...> wrote:
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Re: Any BPF 50 MHz design
"Paul KE7HR"
I ran a fast 6 meter filter design from the AADE software and put the schematic and calculated plot in my Photos section KE7HR. This might be a starting point.
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Paul KE7HR --- In QRPLabs@..., "Paul KE7HR" <ke7hr@...> wrote:
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Re: Any BPF 50 MHz design
"Paul KE7HR"
There is FREE filter design software at:
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It also includes a calculator to determine which toroid to use and the number of turns to complete the design. I usually take what I get from AADE and work with it in the programs from the ARRL book "Expermintal Methods in RF Design" to make it just what I want, but the AADE design usually don't need much attention. I have used it to make filters from LF through low VHF. Paul KE7HR --- In QRPLabs@..., "T M" <f5ozf@...> wrote:
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Arduino Shield 30m on
"Leigh L. Klotz, Jr WA5ZNU"
¿ªÔÆÌåÓýMy 30m MEPT "Multi-Mode Shield" kit from Hans G0UPL is on the air now from CM87.? I haven't had any success with W4HBK yet but VE7IGH is reliable at night.? I haven't measured or calibrated the output power yet, and I'm using short twisted pair to coax to a 25 ohm impedance SteppIR dipole up 12m with no additional matching, so it's seeing about 2:1.? I also haven't done anything about temperature stability, so it varies about 20Hz through the day.? Now it's at 10140+30Hz.Leigh/WA5ZNU |
Re: GPS antenna rain protection and "picnic portables".
"andyfoad@..."
--- In QRPLabs@..., "Philip" <pcteee@...> wrote:
Well spotted Andy, tis indeed a coffee jar lid :)Hee hee ! (See, I do observe!) Coffee jar lids once used here too. My first Top Band AM set up many years ago was a KW160 transmitter plus Lafayette rx. Antenna switch over between the two was a coffee jar lid and a 1 pole 3 way switch poked through the lid and screwed to the shelf. Good luck with your "picnic special" Cheers ! 73 de Andy |
Re: GPS antenna rain protection and "picnic portables".
"Philip"
It's much the same idea as G4JVF's answer. I think he has a set of Well spotted Andy, tis indeed a coffee jar lid :) Good luck with your "picnic special" Philip G4JVF |
Re: Those GPS 1pps problems.
g3zjo
¿ªÔÆÌåÓýOn 16/06/2013 16:38, Robert Bennett wrote:Have a look at the circuit around the 1PPS for the PPS Piggie board here:Thanks Robert interesting stuff. I am sure Hans will crack it, if all else fails a special? v2.01 GPS parameters with v2.02 RF will be the final solution, because the Trimble was fine on v2.01. 73 Eddie |
GPS antenna rain protection and "picnic portables".
"andyfoad@..."
By the way, I want to use my Ultimates as portable units.Dave, I have another U2 here which I am also planning to use as a "picnic portable" unit too ;-) My current thoughts are that I am going to build the second UP501 module that I have into the same style enclosure as I have used for my other U1 and U2's. This would give me the space for: * An 8 cell AA battery container. Dummy cells can also be used to control the PA voltage. 2900ma Vapex NiMh cells are very cheap too. ?11 for 8 of them. * 160m to 10m ATU built in like my others. Keeps everything self contained. * Cut a hole on the top of the enclosure to allow the UP501 (or whatever your chosen GPS module is) to allow a clear RF view to be seen by the GPS antenna. Now I have seen in the CPC catalogue somewhere some nice little plastic units that could be glued or affixed over the module for waterproofing and physical protection. I'm not sure what they call them, but I'll look them up tomorrow in the works paper catalogue and post my suggestion on here. It's much the same idea as G4JVF's answer. I think he has a set of photo's on this group. Phil's plastic top looks a bit like the lid off a jar of coffee - Phil ? ;-)) Just some thoughts... 73 de Andy |
U2 Success
Chris Del Plato KQ2RP
Hi all, Happy to report that I built my U2 kit last week (aside from fully mounting the display in the box, it is complete).? You can see my build here:I boxed it in this case, using this case: which has slots which fit the U2 board nearly perfectly, except for two issues: 1. the display contacts touch the case rail - fixed with some teflon sheet insulation and contact cement, and 2. the turned around PA transistors hit the side of the case and would not allow the board to slide in. I asked a machinist at work to hog out a channel to allow the FETs to clear.? This can likely be avoided if you know you wish to use this box prior to building the kit and can add length to the FET leads and extend their bodies a little further inward on the board. I put it on the air in QRSS mode on Friday evening and saw my first grabbed sigs and then switched to FSKCW to more easily see them: Thanks to Hans (and beta testers) for putting out such a great value kit!? I can see I'm going to have lots of fun with it.? I've just placed an order for each of the new chips and 30 & 40m filter kits to extend my playground. 72, Chris KQ2RP |
Re: Those GPS 1pps problems. (Some bystander thoughts)
"g8voip"
Hi Guys,
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Just in case anyone gets confused, there is no such thing as a Reyax UP501 GPS module! Reyax are simply one of several Far Eastern sellers on ebay. The GPS module being talked about was manufactured by Fastrax, since taken over by ublox (microblox). The UP501 is now an obsolete device now. Looking at the spec should have worked ok with the U2 as I believe the 1 PPS was edge detected in the first release of software and there was the facility to choose positive rising or negative falling edges (or simply invert). Operation with the U1 is far less certain as I recall there was a problem reported and Hans perhaps can confirm that the software uses 100mS as a cross over in the pulse window detector. The UP501 1 PPS signal according to the spec sheet is 100mS +/- a nats whisker so in theory might not work reliably. 73, Bob G8VOI --- In QRPLabs@..., dean smith <g7eob1@...> wrote:
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Re: 6.25MHz ?
"andyfoad@..."
Nice one Hans and all understood.
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Good thinking ! 73 de Andy --- In QRPLabs@..., Hans Summers <hans.summers@...> wrote:
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Re: 6.25MHz ?
Hans Summers
Hi Andy On key-up, the keying transistor Q1 is switched off, and the C1 capacitor is also supposed to mop up any RF leakage too. However some RF *still* can leak through to the antenna! It's many many dB down but if condx are good, QRSS'ing can detect that stuff. Keith G6NHU sent me a beautiful screenshot of slow-hell on the v2.02 and there was a faintly visible carrier between words and between messages. Admittedly it was a very strong signal and only just across the North Sea. But by moving the frequency to 6.25MHz during key-up on Hell spaces or between Hell messages, I could eliminate that faint key-up carrier. It was just a single function call and would fit into the last few remaining bytes so I did it!
FYI 6.25MHz is what is used for the calibration of the 125MHz canned oscillator when a GPS is connected, in the 13 seconds before the start of a frame. 6.25MHz is 125MHz divided by 20. By measuring it for 10 seconds I am able to determine the 125MHz frequency +/- 2 Hz, which is good enough.?
73 Hans G0UPL On Sun, Jun 16, 2013 at 11:39 AM, andyfoad@... <andyfoad@...> wrote:
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Re: Those GPS 1pps problems. (Some bystander thoughts)
g3zjo
On 16/06/2013 10:59, David Atkins wrote:
nearly all the 'recommended' GPS units appear to have integrated antennasHi David That is why I liked the Trimble, integrated antenna, and also an auto switched SMA antenna socket for use with an external (waterproof antenna). Otherwise you could use a separate waterproof enclosure for the GPS and waterproof plugs and socket to connect. 73 Eddie G3ZJO |
1pps and LED trick..
"andyfoad@..."
I didn't comment at the time because I haven't tried it, but yourI suppose there is only one way to find out. Plonk an LED On the output via a 2k2 and see what happens ;-) On my UP501 module I intended to have an LED connected all the time but it loaded it sufficiently to stop the U1/U2 from seeing the pulses so I decided on option 2. Use a push to make button on my GPS box as a simple way to test that the GPS had acquired satellite data and was working. Otherwise I was forever working blind. From a cold start I usually have to wait about 10 mins for the GPS to sort itself out. I just push the little button every few minutes to see if it's got a lock. Once my green led start blinking I release the button to take it back out of circuit and then switch on the U1/U2 and let it all fly. So simple, yet so useful. 73 de Andy |
Re: v2.02k - Twice the fun, WSPR and QRSS together!
Keith Maton
¿ªÔÆÌåÓýEddie, Two showers and a train journey and Hans will have worked it out. 73 Keith, G6NHU |
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