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Re: Heatsinks for TO-92 type transistors
"Philip"
Neat idea Colin, I shall try that today...
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A heatsink I made was from a strip of Coke tin material about 1" wide by 3" long cut with scissors... Roll it up lengthwise on a suitable drill bit shank (bit smaller than the transistor) then twist it (against the rolled direction) onto the transistor case.. Grips well and performs well Philip G4JVF --- In QRPLabs@..., "woodiescbj" <jobaco@...> wrote:
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UQRSS - WSPR Overnight Test.
"David Barber"
UQRSS - WSPR Overnight Test.
A good run overnight, nothing exotic but consistent spots into Germany, and France with also Sweden, Spain and Norway. Perfect operation and frequency has remained accurate. Power measured at the antenna feed point is 103mW. Congratulations to Tony (BZB) who I see had a couple of spots Stateside. David G8OQW *** |
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Heatsinks for TO-92 type transistors
"woodiescbj"
Hi, I was looking to fit a heatsink on the 2N7000 on the single mode QRSS kit and found out that the end caps of some glass fuses just fit over the TO-92 type transistor so keep those burned out fuses, you have to remove the rest of the glass from the inside of the cap (safety goggles and gloves are a good idea) with a screwdriver or drill bit, then solder a cooling vane of your choice to the top of the cap.
Its funny how you tend to keep things, I have a draw for useless stuff old batteries, empty ball point pens, burned out fuses, etc. 73 de Colin DD5CF / G1ZOS |
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Re: WSPR Locator.
Tony Volpe
Do you have a GPS on your kit??
If my GPS loses lock (it's indoors and sometimes does) the correct IO94 decoded by the GPS and displayed on the kit is substituted on the WSPR database with the stored value that I loaded onto the WSPR website in my member info. This contains two extra letter characters. I can't explain why, but I know it is something coming from the WSPR website because the actual square saved on there is wrong. I live about thirty yards over the line between IO95EA and IO94. I am actually in IO94, but didn't realise that until I got the GPS and fitted it to the kit. That's the best I can do by way of explanation. 73s Tony G0BZB |
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WSPR Locator.
"f6gwb"
Hi all,
I am puzzled seeing that the spots I get from WSPRnet for my little U-QRSS-kit are showing a 6 characters locator while I typed only 4 characters in the "locator" parameter of the configuration settings ! Maybe the WSPR software supplements the 4 characters locator received using the 6 characters locator found in the WSPRnet member's database or with QRZ.com Or HamCall or other source ? Anyone knows ? Gerard, f6gwb. |
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Re: Low frequency from U-QRSS-kit.
"f6gwb"
Hi Tony,
Thanks for your last post. I think you are wright, I will let C4&C5 as the are now, at least for a while as this seems to work properly. It also seems that the propagation last night and today was not so generous than yesterday and the night before, as I got only a few local WSPR spots. But wave propagation is so fanciful ! 73s QRO. Gerard, f6gwb. |
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Hams' Law # 23
Grover Cleveland
----------------------- On Aug 26, 2012, at 7:51 AM, Stephen Farthing <squirrox@...> wrote:
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Re: Can't now decode my own WSPR signals.....
"woodiescbj"
Hi Steve, you are right just about all my homemade equipment has holes for trimmers U-QRSS and QRSS included, thanks also for the offer of a new 160m Xtal, if by chance it is not the Xtal I will of course reimburse via PayPal.
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73 Colin --- In QRPLabs@..., Stephen Farthing <squirrox@...> wrote:
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Re: Can't now decode my own WSPR signals.....
"David Barber"
开云体育How true!!! ? J ? David G8OQW *** ? ? From:
QRPLabs@... [mailto:QRPLabs@...] On Behalf Of Stephen Farthing ?
? There is an little known law of ham radio that generally is infallible but they never teach on courses or test for in licence exams. It goes like this :- ? If you have a project that works and you put it in a case it stops working as it did without a case.? ? I have noticed this several times. For example last week I got around to putting my frequency counter in a case. On the bench ?it was accurately calibrated. In the case the calibration was out by 16 Hz, so I had to change the trimmer setting to compensate. If you look at "old school" equipment it often has a hole in the case to allow trimming without having to take the board out of the case. If you are casing your beacon it might be an idea to do this.? ? There is a related law which goes something like this :- ? if you have a chassis mount BNC connector you want to use you can never find the bolts to fit it to the chassis, or the case of the ones that dont need bolts, the earthing washer.? ? 73s Steve ? ? ?
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Re: Can't now decode my own WSPR signals.....
"David Barber"
Are you using a GPS?
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I see you're being spotted with a 6 character locator showing, mine only does 4 characters - am I missing something? And for some reason I'm seeing large DT figures here for my transmission of -1.8 to -1.9 and inconsistent local decodes again. Not quite sure what's going on as the frequency has remained absolutely stable. David G8OQW *** -----Original Message-----
From: QRPLabs@... [mailto:QRPLabs@...] On Behalf Of g4sfs Sent: 26 August 2012 15:32 To: QRPLabs@... Subject: [QRPLabs] Re: Can't now decode my own WSPR signals..... Hi David/All That's interesting and I can now report that my WSPR is working once again! I found that I had to change FSK AdJ to 1,250 when previously it had worked without a hitch for weeks on 0,700!! I'm currently tx every 2 mins while I check that all is ok and I'm getting reports back with drift of 0 and -1. My own monitoring is providing decodes again!! I have to say that I'm really surprised that FSK ADJ has had to be increased so much with a minor shift in osc freq. Funny stuff this radio!!! I will revert to 10mins tx shortly and leave it running this evening to see what happens, before I put the covers on again! Hopefully neither actions will stop it from working!! 73 de Peter G4SFS |
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Re: Can't now decode my own WSPR signals.....
Stephen Farthing
Hi Guys,
There is an little known law of ham radio that generally is infallible but they never teach on courses or test for in licence exams. It goes like this :- If you have a project that works and you put it in a case it stops working as it did without a case.?
I have noticed this several times. For example last week I got around to putting my frequency counter in a case. On the bench ?it was accurately calibrated. In the case the calibration was out by 16 Hz, so I had to change the trimmer setting to compensate. If you look at "old school" equipment it often has a hole in the case to allow trimming without having to take the board out of the case. If you are casing your beacon it might be an idea to do this.?
There is a related law which goes something like this :- if you have a chassis mount BNC connector you want to use you can never find the bolts to fit it to the chassis, or the case of the ones that dont need bolts, the earthing washer.?
73s Steve |
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Re: Can't now decode my own WSPR signals.....
"g4sfs"
Hi David/All
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That's interesting and I can now report that my WSPR is working once again! I found that I had to change FSK AdJ to 1,250 when previously it had worked without a hitch for weeks on 0,700!! I'm currently tx every 2 mins while I check that all is ok and I'm getting reports back with drift of 0 and -1. My own monitoring is providing decodes again!! I have to say that I'm really surprised that FSK ADJ has had to be increased so much with a minor shift in osc freq. Funny stuff this radio!!! I will revert to 10mins tx shortly and leave it running this evening to see what happens, before I put the covers on again! Hopefully neither actions will stop it from working!! 73 de Peter G4SFS --- In QRPLabs@..., "David Barber" <david.barber@...> wrote:
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Re: Can't now decode my own WSPR signals.....
Tony Volpe
Yes Peter, Mine moves down when the TX comes on too. I can't say exactly by how much. I had thought it was my not wonderful power supply, but it may be some kind of loading issue on the oscillator. To be frank, wspr asks a lot of an oscillator. If you were on cw, you'd hardy be likely to notice a few htz change. Here it counts, especially since the micro controller is varying the frequency by 1.4 htz to create the wspr tones and trying to hold the oscillator stable, though I don't think it does that when wspr is actually transmitting. Hans wrote me some interesting words the other day when I was discussing the way my fsk width changed. I hope he won't mind me quoting them here - it will save him the trouble of repeating them, and I know he has a lot of demands on his time. Here is his note to me on changing width of fsk when frequency alters:
HANS QUOTE STARTS: "Firstly it is important to realise that a graph of frequency (vertical axis) against varicap diode voltage (horizontal access) shows a curve, not a straight line. E.g. see this image??from my varicap diodes page??.?
The FSK applied by the microcontroller is a reverse voltage to the varicap (the 5mm reverse-connected Red LED In the kit). The microcontroller assumes that the frequency/voltage line is a straight line. It uses the FSK per Hz ("FSK Adj.") setting which you have entered in the configuration menu. However, this setting is only valid at one particular reverse voltage (i.e. one particular frequency). So if the frequency drifts far from the one you have set, then the actual FSK Adj value would differ from the value you set. This would case the FSK size to grow or shrink.
If your FSK Adj value is large, and your oscillator frequency is a long way from the actual target value you have set in the configuration menu, then the GPS will steer the frequency a long way, and this will cause the operating point to move along the line to a point where your FSK Adj value is now incorrect to generate the amount of shift that you need.
What FSK Adj. value do you use?
I think your problem could be resolved in one of two ways:
1) Put the kit in the TEST mode, with the GPS connected. In this mode, the display behaves as a frequency counter. The GPS doesn't lock the oscillator, it is just used to accurately measure the frequency so that you can tune it accurately. Then use the trimmer capacitor to tune the frequency as close as possible to the target frequency value you have set in the configuration menu. Now change the "FSK Adj" value experimentally to get the right amount of shift on Argo. Remember that in TEST mode it shows a square-wave, set the Speed to 003 for example and then you'll get 3 seconds low, 3 seconds high. With FSK Hz set to 4Hz, you should see a 4Hz shift if your FSK Adj value is set correctly. So the trick is to get a correct value of FSK Adj, to get the correct shift, and on the correct frequency (very close to the frequency you set). Then when you move to WSPR mode, the microcontroller will only have to make small adjustments to correct any drift occurring. The position on the curve I described will not move far from where you set the frequency up, and so the error in FSK will be small. In other words: the microcontroller + GPS is intended to be able to slightly correct the frequency due to drift. It is not intended to completely fix any situation in which the oscillator isn't well-tuned in the first place. Do you see what I mean?
2) If all that still doesn't work, then you could try increasing the value of C3 from 22pF to 47pF (or just put another 22pF in parallel with the existing one). This would let the microcontroller have a more aggressive control of the frequency drift. That gives it a greater tuning range, but with less precision. Anyway it would mean that the GPS would be able to correct a larger frequency error, without moving the operating point on the curve as far.?
Generally I think that if you set it up carefully as in 1) above, then that may well solve your problem. This is how I would tackle it, anyway. Please give it a try and let me know how it goes." END OF HANS'S remarks. That explains why it happens - and following the instructions put it right. BUT - the solution only lasts until the oscillator moves again, which in the case of mine, it certainly will do.?
In your case, putting the thing in a box may also change the frequency slightly from where it was set. We are talking very small changes here and the environment is important for that. I am compounding the challenge for my kit by running it at half a watt output (9.2volts on two BS170 fets). This generates extra heat even though I made a decent sized heat sink for them. I tried to get rid of the drift by clipping a crystal heater onto the 10.140 crystal. I have two old 16000mhz down convertors which use have two in each of them. These are old Murata BM500N crystal heaters in them. They are meant for twelve volts but I applied the 9.2volt pa voltage to them and they warm the crystal. However, they don't have a lot of effect on the frequency drift of -2 to -3 that I am getting on my 'hot' kit. I suspect that the frequency changing effects may be on changing capacitance by heating the board through he legs of the output fets. It is warm underneath them and it would only take tiny changes in capacitance to move the frequency by one or two parts in ten million which is all we are talking about. As I said, I have voluntarily compounded the issue by running it hotter and we really are talking tiny frequency changes. Nevertheless - I get loads of decodes from far and wide and get into VK about once every three days depending on the condx. It's a great little kit, even if it is a bit hands on at times. Keeps me out of mischief anyway and for next to no outlay too...
:)))
Regards and I hope Hans is OK with my quoting his explanation.?
73s
Tony G0BZB |
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