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Re: 20m+WSPR+Loop Ant+TX without computer
开云体育FYI?I use my cell phone and have no issues! On Aug 22, 2023, at 1:16 PM, Mustafa Umut Sarac <mustafaumutsarac@...> wrote:
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Re: 20m+WSPR+Loop Ant+TX without computer
Hello Bruce and all, I think I will spend my last dime on transmitter and antenna and would not afford GPS. Is there any online clock which will transmit the GPS timing free . And I would not want to report to everyone my exact location worldwide. Does 5 watts power wspr 20 mt transmission with my close range loop antenna affect my health ANYWAY ?
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Re: 20m+WSPR+Loop Ant+TX without computer
Hi Mustafa
Maybe look at the U3S. That is transmit-only, and with the addition of the QLG2, bullet-proof.
Roger
8P6RX
Get
On 22 Aug 2023, at 13:54, Mustafa Umut Sarac <mustafaumutsarac@...> wrote:
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Re: 20m+WSPR+Loop Ant+TX without computer
I have a QCX +5W and it runs WSPR 24/7
You can set the clock manually after start up and you can afford to gain or lose a second before reception of your signal is a problem. ?Timing is controlled IIRC by the system clock crystal which is low cost and although you can adjust it manually via the menus it will still drift as temperature changes? if there is a power interruption in WSPR mode it will restart with the clock wrong? By far a more superior solution is to buy and connect the optional GPS board which will trim the TX frequency every time, calculate your Location code and update the clock between transmissions . after an unexpected power loss the WSPR transmission will restart and after running wrongly timed once the frequency, timing and location will all be checked/updated? |
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20m+WSPR+Loop Ant+TX without computer
Hello there , I am optimizing everything for my condition. I looked at WSPR sites and found most contacts are for 20 meters band. I will build a 20 meters loop antenna for in room use or on balcony use. My computer is not functioning correctly and I will not plug the transmitter into the computer. I will not receive?and I will not report. I learned that WSPR transmission depends on correct timing , does the QRPLABS?transmitter have a clock which I will be able to correct manually . I will TX a few extremely?short times a day. Best Regards, Mustafa Umut Sarac Istanbul |
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Audio level limiting with diodes?
I recall at one point folks in the Bitx20 boards were discussing a simple hack to avoid blowing out eardrums on transceivers lacking AGC - They would simply use a couple diodes between the headphone lines to ground, so higher voltages would get bled off through the diode.? I don't recall the precise details, but the principle seems like it might work.
Obviously it is a kludge and probably sounds terrible when it gets to audio limiting, but it might at least prevent you from getting blasted off your chair by a sudden loud CW signal... Thoughts? -N1EDC |
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Re: No QMX Flash Drive.
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Re: #qmx QMX and waste heat from the finals
#qmx
I strongly recommend using a VERY thin layer of thermal paste between the BS170’s and the PCB. Mechanical surfaces are not perfectly flat - neither the flat of the FET package nor the board. A thin layer of paste fills in these microscopic gaps. Don’t glob the paste down as this will make things worse. Use something like a credit or debit card to gently scrape away excess paste for optimum heat transfer. On Tue, Aug 22, 2023 at 10:29 AM Frank <dc8fg@...> wrote:
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Re: QDX rev 5 Troubleshooting
Thanks for the advice John and Nick, testing did indeed show that D3 and D6 went to 0 (or as near as dammit!). I swapped L9 with L5 and confirmed continuity with R9 and C11, however the same fault persists. So could it be Q5 or do the 0v on D3 and D6 rule it out? |
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Re: Non-toxic antenna throw weights
I pick up a rock and either use a girth hitch or a slip-knot (which also happens to be a hitch now that I think about it) to tie the para-cord around it.? I don't wear a helmet... or suspenders.? Though out here in Utah, you have to be carful of which rocks you pick up, they might contain uranium and would be more hazardous than lead.
Joshua |
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Re: #qmx QMX and waste heat from the finals
#qmx
On Tue, Aug 22, 2023 at 06:45 PM, Chris KB1NLW wrote:
The flat surface of the BS170 contacts the surface of the PC board.? Being a six layer board this should dissipate heat better than the QDX.? (I do put a little thermal paste on mine to help conduct.)? Hans has explained that the washer on top of the BS170 is to press the BS170s down to make good contact with the board and not primarily to dissipate heat.Ah yes - makes sense. Mainly I was worried about IC503, which is over the discharge surface and gets very warm. |
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Re: #qmx QMX and waste heat from the finals
#qmx
开云体育I've been following this thread and others regarding what takes out the Finals. I've built 2 QDXs and one QMX. Both the QDX rigs blew the finals within a short time of building. I don't know for sure why in either case. After that I put some serious heat sinking in the QDXs and haven't lost them in the 9+ months since. The other day I really, unintentionally for sure, tested the theory of an open antenna blowing the finals with high SWR. I was in a hurry and hit TX and saw no power out. Switched the meter to SWR and saw a SWR of 10. By that time it had been in TX at least 10 seconds. Quickly killed the TX and connected the antenna. Tried again and all was good. I've had several QSOs in Olivia chat mode with key down times of up to 10 minutes since. All is good. No damage evident yet.?Why the finals endured my attempt at their destruction I can't say, but I'm sure heat sinking helped. 73, Cliff, AE5ZA
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Re: #qmx QMX and waste heat from the finals
#qmx
The flat surface of the BS170 contacts the surface of the PC board.? Being a six layer board this should dissipate heat better than the QDX.? (I do put a little thermal paste on mine to help conduct.)? Hans has explained that the washer on top of the BS170 is to press the BS170s down to make good contact with the board and not primarily to dissipate heat.
I have lost one BS170 on my QMX most likely due to high SWR possibly during? auto antenna tuning or even transmitting without any load - though I don't recall? doing this.? Even with better heat sinking it may not be possible to protect the BS170s from the power reflected into the radio from high SWR.? I believe Hans may build in firmware protection based on the SWR hardware sensing in the QMX. |
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Re: Non-toxic antenna throw weights
Hi Bruce,
"Good on ya" for making an extra effort to avoid spreading toxic materials!? I use 15 ml eye drop bottles full of heavy material.? They fit nicely inside the 1-inch (nominal) schedule 40 PVC pipe in my launcher's output tube.? Sometimes I wrap a little tape around the top to reduce blow-by leakage.? For a while I filled them with steel brads.? Then I found a box of lead fishing weight bars at a garage sale and put them inside the bottle instead.? That enabled the bottle to be heavier and thus more able to pull the fishing line through the tree branches.? This also increased the retrieval rate of the throw weight to 100%, keeping the lead out of the trees and dirt.? My pneumatic halyard launcher that resembles those cited in this thread.? It uses an unmodified electric irrigation valve driven with 18 V from 2 transistor radio batteries in series.? Activating it with a small pushbutton switch enables me to hold the launcher's position steady during launch.? Pumping it up to 7 bars gets the weight and fishing line over 40m high.? 3 bars is good for about 15 meters height.? But the pneumatic launcher is too bulky and heavy for hiking.? My lightweight solution is a wrist-braced slingshot.? I tie the fishing line around a stone.? It takes several tries because I still haven't figured out how to keep the rock from hitting the fork. Cheers, Halden VE7UTS |
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Re: #qmx QMX and waste heat from the finals
#qmx
开云体育Frank,No problem here with heat even in a chat mode with key down time of 10 minutes or more. I think the QMX doesn't get as hot as the QDX. 73, Cliff, AE5ZA
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#qmx QMX and waste heat from the finals
#qmx
Hi all, So, I wonder if there is any construction possible to dissipate the heat of the finals to bottom cover of the housing. My idea is: a piece of copperplate soldere to a bolt which is connected with the washer which is on top of the finals.? The copperplate must be in tight touch with the bottom of the housing. |
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Re: #qmx QMX is up and running - except 30/20 - UPDATE - UPDATE
#qmx
Hi all, Thanks to all for helpull hints! |
Bruce Akhurst
Joshua KJ7LVZ
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