Can anyone advise? I built this little kit a few years back & it worked well. Then suddenly started sending a dead signal. I dont know why & never got around to it at the time due to kidney failure. I've now had a transplant & am now facing this little problem.

TIA Gary, 2E0BFJ

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Hi
I am not saying good or bad.? When I get the kit done and install it I will know then.
I favor the metal case over the 3D print cases I have seen. It may be a little quieter from radiated interferance.
I don't know

I am impatient to start the radio kit.
Dennis

This article.

https://www.google.com.au/url?sa=t&source=web&rct=j&url=http://www.norcalqrp.org/files/Tayloe_mixer_x3a.pdf&ved=2ahUKEwi36d_cutjhAhXFbSsKHXMZAooQFjAAegQIBRAB&usg=AOvVaw3V9iSmiFxa8wcdVf5OEluL

I have been thinking about this, bought some parts but have been distracted by other things.

My plan was to abandon the bpf, replace with a broadband splitter like in the qrplabs receiver, use a qrplabs relay board to switch kow pass filters and adopt the class e pa circuit from the kd1jv soda popa which has the similar architecture of the qcx tx path, ie si5351, buffer, 3xbs170 and uses the same inductor coil for each band. So the only switching is lpfs. May need to add a 3mhz hpf before the splitter to keep bcb signals out.?

This article on the tayloe detector suggests it may be possible to run with bpfs due to inherent bpf selectivity / high q of the detector.

Compromises on a fully switched bpf, lpf, pa coil approach could include power output, opposite sideband rejection, receive quality with benefit of simplicity, size.

I have read on the forum that the code may not set phase of the iq signals correctly for big freq jumps. Dont know about this.

73

Simon
VK3ELH

Big thanks dear Hans! I wrote you a mail.

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Sorry to be a bit thick here but are you saying this is good or bad????

It takes very little power to spin a fan fast enough. Here i have picked off some RF into the load and rectified it (photos 2 and 3. ) The toroid turns do affect the impedance a bit above 30 mHz, but it's worth out to get proportional cooling. In the first photo I just used a battery and a 50C thermal switch.

Sooner or later for sure?? :<)
Dennis

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Check your emails from QRP Labs or log into your QRP Labs shop account.
If it's a recent order, the SNo# should be contained in your Past Order Details?

Older orders

Alan

--

I just received my 40 meter QCX kit, and I was looking for a "serial number".? My QCX-20, has the serial number 748.? It might be nice to know, as maybe someday, it maybe part of a QSO party exchange, or maybe I have lucky number 20, 000 or something!? 73, de Karl, KO8S

--

The case I ordered at the same time as the kit transever

On 17/04/2019 14:08, John Kirby wrote:

Nick,

That LED dummy load is kit I built 10 or more years back and have long since lost the manual.

The pcb is marked such...

XTAL SET SOCIETY
10W SMART DUMMY LOAD
www.midnightscience.com

My web search found 'dot net' and 'dot com'
and this...
?
... but no help with my kit.

Maybe you will have more luck other than gQQgle

The high Watt resistors (image) are 300 Ohm each

Based on the low Watt resistors;
one set of 4 (1000 Ohm) and
second set of 4 ( 100 k Ohm)

?l?? >auusme<??? four of the diodes are zener ...
????? and maybe all different voltage
???? >else<? how would one 'calibrate'? 1W, 2W, 5W 10W
???? with any degree of accuracy?
?????
and other 4 diodes maybe something like 1n 4148 or 914

I also >assume<? LEDs? are? 'low'? current type

The rf ground plane (second image) prevents reverse engineering a schematic.

72 73
John
N3?AZ

John,

Very many thanks - I'll have a ponder but I think the assumptions are
correct - if I come up with anything I'll post to the group.

Regards

Nick
M0HGU


--
"Woof bloody woof."
-- Gaspode the Wonder Dog
(Terry Pratchett, Moving
Pictures)
18:15:02 up 1 day, 5:34, 8 users, load average: 1.47, 1.05, 0.79


--
73 Nick M0HGU

Finally some spring weather,? 1st light coat of paint on the can & front panel. I should be back up on the air in a few days, just in time!

For outdoor ham radio activities I bought some years ago a battery pack from Headway:


It has no built-in protection - therefore you are free in your choice.?

I have tested it with a Kenwood TS480-SAT and you can get 100W Power for more than 90% of the capacity. That means, voltage under load is very stable for a long time. For QRP rigs like the QCX this should be a very, very loooong time :-)

73
DL8CQ

I've used a few of those 150 watt terminations on various heatsinks. The power rating is no joke-- on a large fan-cooled cpu heatsink they will dissipate 149.9 watts all day long. At 150.1 they explode. Well, that's how it seemed anyway...... I've gone over to the 250 watt units for my small dummy loads now. JS6TMW?