Go to officemax or staples and look at the avery stuff.
They make a letter sheet size page for laser printers.
It is clear and the one I use has matte finish and not
the shiny stuff.? Make a front page layout and print
on plane paper first to cut and fit to make sure
everything is in place.? No use wasting a valuable
sheet of label material.

Went to my old friend DeepSeek and asked and got the
Avery #4397 number.? One peek at Amazon.com and below
is the result.? You can see why I recommend you play
with paper first before committing to the final print.
IMHO.? Note that DeepSeek lied again and gave the old
number and not the current one.

If you use only 1/2 or less, you can refeed the remainder
for another project later.

Take your credit card with you.

chuck, aa7fo

BTW.? I'm going for just the 18" brake.? I have no use
for the other functions.? Just for a note.

--

I use the PCB on all my PCB work.? It'll handle anything that I have from abcfab and
that is about everything he sells.? :-)

I have used it on 0.030 Al and it is rated for 1/4" max, but there is no way I am ever
going to need that.? I will buy an 18" brake in a month or two to go back to making
enclosures again.

You see the platform I made to be able to cut at 90.00000 degrees? OK, close.
There is a AA7FO secret.? Get some C clamps and use some boards to clamp
in place to hold the right edge and the opposite edge from the blade.
The torque generated is impossible to oppose by hand and the board will
rotate by a degree or two when the edge gets to the last part of the cut.
Been there.? Done that.

Here is the check, and I wrote this up decades ago.? Take a scrap piece of
PCB.? Cut all four edges in order or rotation, either CW or CCW. Then
measure the corners to see if they are indeed 90.0 degrees.? You've
got the technique down pat if you get close enough.? I know, it's an
OCD thing.? I attribute to two years in kindergarten and knowing
how to stay in the lines.? :-)

FYI

chuck,? aa7fo,? local sales rep for everything you need

The shear is a Vevor at $133.99 on Amazon, but they probably
all come from the same sweatshop.

If I make a video for youtube, will more than 6 of you watch it?

I have a? way using the shear and a Harbor Freight brake that you might see in
some of the old projects.? Attached is the lower section of one in use.

thanks,

chuck

Q:? What's in your wallet?
A:? Nothing.? I spent it all on lab equipment and parts.

Last year I purchased, from Amazon, a 12" shear.? Warning.? This puppy is
heavy and not for those with knee and hip problems.? Get a couple of HS
football players to come over for milk and pie to help you out. Free
shipping.? Priced about $125 USD.? Brand is covered up by fixture.

A few days ago I took a hand held router and made a platform to securely
hold the PCB material for cutting.? No plans available.? One of a kind.
I have 20kg of PCB material gathered over 30 years from abcfab on ebay.
He used to be in NE, but may have now relocated to FL.

My plan to use as much as possible by the end of Sept.

People may be thinking, how does the village idiot know how large to
make a board for a project.? Well, he doesn't.? Just make sure it's
large enough.? Shear away the unused portion when done.? Some of the
left overs can be used for little critters.

Thanks to all of you for sharing what you use.? It helps the rest of
us save some time and money.? Time being the most important commodity.

Enjoy,

chuck, aa7fo

开云体育

The ADC 40 IF crystal filter uses three crystals with 150 pF caps on the ends and in the middle. EMRFD? 3.21 mentions this type of filter, known as Min-Loss and a derivative of Cohn's extensive filter data. And 3.23, middle column near the top mentions the exact filter the ADC 40 is using, and says the N=3 filter uses 146 pF capacitors and 181 ohm terminations. This fills in my missing info on trying to make the ADC 20? 9 MHz filter--the filter uses the same 150 pF capacitors, just the crystal frequency is different.

I made a simple test fixture with 3 sockets to test the 9 MHz filters. Transformers on input and output, 50:180 ohms, I'm using FT37-43 with 10:19 turns, and the SA and tracking generator to sweep the filter and find insertion loss and 3 dB bandwidth. I bought a bunch of 9 MHz crystals and sorted them for frequency with the G3UUR test oscillator, then matched them into sets, using 20 Hz max separation of crystals. All these crystals are the HC49S (low profile) version--the normal HC49 tall version seems to be "unavailable", though Mouser still lists the 9 MHz version, but they have zero in stock, and "April 22 expected delivery" (those are the crystal W7ZOI used for his 2020 paper about 9 MHz crystal filters, available on his web page). All the crystals I got are fairly low Q--40,000-70,000, with most in the 50k-60k range--so nothing like the crystals W7ZOI used with much higher Q. And with all my testing it turns out one can use the G3UUR test oscillator to gauge how good a crystal is just by its output. I run the output to the DSO, with the 10X probe. The DSO has the handy on-screen display of Vp/p that one can enable. Perhaps due to the change of the emitter resistor to 3.3k ohms, all these crystals are completely stable in frequency and amplitude as soon as you plug them into the test oscillator. My DSO gives the frequency down to the Hz, which is what's needed to accurately match crystals. Of course I don't touch the crystals but use tweezers to handle them, so I don't add any heat to them. I happen to have a few of the tall HC49 9 MHz crystals on hand, and they give amplitudes in the 0.7-1.1 Vpp range. But the short HC49S crystals all are in the 0.3--0.5 Vpp range--much lower.

73,

Steve AA7U

Here's one link to the DE-5000 manual in English. Note you must do the initial calibration using the test leads you plan to use. You only do that once, then you're good to go from then on as long as you don't change the test leads.

Steve AA7U