Good morning Hans.....your suggestions and advice, please?  Thank you.  

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On Oct 28, 2021, at 9:50 pm, Mel Snyder <melsnyder@...> wrote:

First Japan, and then China, crushed the US ham equipment makers. The speed with which old-line companies like Hallicrafters, National, E F Johnson, Clegg, etc crashed in the late 1960/early 1970s was breathtaking.

I’m old enough to remember the transition and to that I’d add Heathkit, so it wasn’t just labor costs that killed them. I suspect one reason was a broad economy of scale. When the Japanese used the transition to pc boards and transistors to take over electronic entertainment, that created an economy of scale (parts, assembly lines, manufacturing equipment) that helped the ham market despite its much more limited sales. And that transition was a factor. As a ham in high school, a local TV repair shop gave us old U.S.-made TVs that were no longer worth repairing. Almost all were hand-wired, with resistors and wires having to be placed and soldered from one tube socket to another. That’s an expensive way to build and TVs were expensive. We got our first TV the summer before my second grade. We were still using it ten years later when I went off to college.

To some extent the makers of ham gear also suffer from the same problem that haunts the makers of small sailboats. No matter how well-designed and built a small sailboat is, within a few years after it enters the market, the new sailboats are competing with used ones. Particularly in fiberglass, they simply don’t wear out. I bought one for $1200 well-enough designed that it had a longer run on the new market than most, but even there new could not compete with used. Someone in boat making told me that if it had gone back into production, it would have to sell for $15,000. $15,000 cannot compete with $1200.

Of course that ham radio market has another factor. Few people collect small sailboats much less large ones Quite a few hams collect old radios. That keeps their used price high.

There is a danger when large companies in democracies lose their ability to make some products, particularly with products that are vital in either pre-war tensions or wartime. Germany. for instance, dominated the making of quality binoculars at the outbreak of WWII. The Brits needed them, so I have been told an unwritten agreement was worked out. The Germans did nothing when Swiss companies bought (for resell to the Brits) far more binoculars than they needed. And the Brits did nothing when the Swiss bought larger-than-needed quantities of special metals needed in steel alloys.

Much has been written about how the Brits benefited from breaking Enigma, Germany’s military code. Little is said about how how those coded messages were received, many of them short range messages between nearby units. In many cases reception meant huge rhombic antennas atop 100-foot poles and connected to state-of-the-art National HRO receivers bought from the U.S. The ability of the U.S. to make such radios in the thousands was vital to the war effort. A memory of that still lingers. What remains of U.S. manufacturing of high-quality communications gear is driven by military contracts given to companies such as Collins.

Here you can find the history of those HRO radios. Note how they used coil sets to cover a wide range of frequencies.

https://radioblvd.com/National%20HRO.htm

—Mike Perry, WA4MP

I have a PX3 Panadapter for my Elecraft KX3. I have wondered whether it could be adapted to my QCX radios.

On 29/10/2021 11:38, Alan G4ZFQ via groups.io wrote:

What I wrote below probably makes little sense, SDR is not easily explained. Note that all Hans' receivers are SDR front ends.
2 mixers, I and Q signals produced and cancelled.

I do not know where the basics are presented simply. I wrote something on this page and other Softrock pages in a crude attempt to explain.
https://sites.google.com/site/g4zfqradio/connecting-soundcard-sdr-to-computer/sdr-transmit-and-receive-image-rejection
This refers to soundcard SDR which is what you get when you feed IQ signals to a soundcard but fundamentally any SDR is the same.

73 Alan G4ZFQ

Trystan

Would a panadaptor be pretty useless with a direct conversion receiver though, because you'd see a whacking great big signal at the frequency of the QCX?

No, SDRs are direct conversion. Many do not avoid this situation although it is suppressed to varying degrees. The exact centre is best avoided in many SDRs
Note that the actual local oscillator is right at the centre and the ADC sees it as zero Hz. No actual response at 0Hz.

--

Far too tidy!  But beautiful.

Without tea the whole of the UK would grind to a halt.

Some years ago the MOD building in Whitehall was refurbished. 150 electric kettles were found.

Jim   G4EQX

Trystan

Would a panadaptor be pretty useless with a direct conversion receiver though, because you'd see a whacking great big signal at the frequency of the QCX?

No, SDRs are direct conversion. Many do not avoid this situation although it is suppressed to varying degrees. The exact centre is best avoided in many SDRs
Note that the actual local oscillator is right at the centre and the ADC sees it as zero Hz. No actual response at 0Hz.

73 Alan G4ZFQ

Technically, the fuse in the plug is required to protect the cable between the plug and the appliance. Protecting the appliance itself is another matter.

73, Stay Safe,

Robin, G8DQX (about to brew up)

PS: This arrangement, due to sockets being supplied from a high current ring circuit, made sense in a historical context, rather like SRBP mains plugs & sockets.

I am now running on Lora Asset Tracker .ino firmware. Can i go airborne with this. I could not find the line you suggested changing in the pico tracker .ino file

The asset tracker works well but just a question about Altitude and Acceleromtert dusplays I can display one or the other but not both at the same time

Either altitude is zero and accelerometer displays Or altitude displays a value and acceleratometer  is greyed out .

regards

r

My QDX is confirmed, after a couple of overloads on the order page. Even got a TNT email saying it was on the way and then another saying it was delivered to Germany. Apparently TNT re-use their consignment numbers.
I intend to remote mine using RigPi. The license cost about £30 but I bought one to remote control my HF set at our local club where there is a decent antenna, but not being a Linux exponent I could never get the VOIP working. It worked well on digital modes.
I ended up with W10 software to remote control the HF rig, and it's been on test for three months and hasn't faltered.
I'm in a small bungalow in a small plot so the antenna is a compromise, but I can do wonderful on FT8.
Luckily I have a short antenna run to the HF antenna and will use the RigPi license to test remote operation with RPI4. All low power and maybe run it with a solar panel. If that system works for digital it could be mounted in a weatherproof box at the antenna if the feed was long. Anyway has great possibilities. looking forward to it coming.

Would a panadaptor be pretty useless with a direct conversion receiver though, because you'd see a whacking great big signal at the frequency of the QCX?

"Volts jolts, mills kills."

In a domestic home, here in Blighty, you would only encounter one type of plug and socket.

The 13 Amp type. Its fed by a 30 Amp ring main.

Also in every domestic home here in this great tea-drinking nation, is an amazing feat of engineering called an "Electric Kettle". I kid you not! 

Must get on, I have a cup of tea to drink.

Tally ho!
Trystan G0KAY

I presume that everybody knows this already - or not?
Never fill up vias with solder! For RF to travel from one layer to the
other it needs to travel via the surface. Filling vias with solder moves
the surface to the wrong side and the way RF has to travel becomes far
longer.

On Freitag, 29. Oktober 2021 05:18:20 -03 David Wilcox K8WPE via
groups.io wrote:

My Thanks to you Hans and the others who helped me understand what
those dots and mini holes are for. A well designed kit and fun to
build and more fun to use. Thanks again.

Dave K8WPE

David J. Wilcox’s iPad

On Oct 29, 2021, at 12:06 AM, Hans Summers <hans.summers@...>
wrote:


Hi Dave

Yes, they are vias.

QRP Labs kits use 2 layer boards. The vias are necessary to connect
the bottom and top layers of a signal trace as it is routed around
the board and sometimes it has to change from top to bottom in
order to avoid obstacles (other traces).

A common PCB layout technique is to run horizontal traces along one
side of the board and vertical traces along the other. I also start
my board layouts like this, then as the design progresses commit
may violations to make everything fit well. By "horizontal" and
"vertical" I mean, as you hold the board in front of you. X and Y
axis if you like... Not Z axis which is a hole drilled through the
board itself.

In some QRP Labs boards I do indeed use two sizes of vias, one for
signal connections between the two sides and one for ground plane
stitching. Sometimes I even use a larger size to via for power
lines which will be carrying relatively more current.

The minimum size via has to be chosen carefully because PCB
manufacturers have constraints like minimum drill bit size, and
minimum spacing between drill holes and nearby traces etc etc. As
you go smaller and smaller with feature sizes there comes a point
where the manufacture is still possible but the cost jumps
alarmingly and suddenly.

Some folk say you can't mix analog and digital domains on one PCB
such as in this case, digital circuits and sensitive RF circuits.
Others say you have to use 4 (at least) layer boards so you can
have signal layers on the top and bottom and supply planes in the
middle so have a good nearly continuous ground plane. Again more
layers more cost.

QRP Labs boards are 2 layer and successfully house digital and
analog domains on one board. This achieves compact low cost designs
that work very well. The vias are a crucial part of this.

I go to enormous trouble to ensure that the two sides of the board
both have as much ground plane as possible. Everywhere there isn't
a component pad or a signal trace. The vias link the two sides
together and placing them at intervals of not more than 0.1 inches
ensures that even up to VHF frequencies or higher, the PCB looks to
RF, like a near-perfect uninterrupted ground plane. I try to make
sure that if there are signal traces on one side of the board,
there is ground plane on the other side. Signal traces on one side
should cross, if they must, signal traces on the other side at
right angles, so as to minimize inductive or capacitative coupling.
I move components and traces around to try to be able to imagine
the dual-layer ground the way RF will see it and totally minimize
the size of any RF holes or gaps.

The result is good but it doesn't just happen by chance, it takes a
lot of hard work to layout the PCB.

73 Hans G0UPL
http://qrp-labs.com


-------- Original message --------
From: GM7TFP <dbrankin@...>
Date: Fri, Oct 29, 2021, 1:22 AM
To: QRPLabs@groups.io
Subject: Re: [QRPLabs] QCX PC board spots and mini holes
Hi Dave

I suspect what you're seeing are indeed the vias (as described by
others), some of which may have been filled or semi-filled by the
soldermask ink due to viscosity/meniscus effect. It's overprinted
once the vias have been drilled.

Derek

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