What's on your Workbench?

[VK7HH]

Tim, keep an eye out for old "Fluid Heads" that pop up on eBay etc.

I found one of these lying around being unused. It's now in storage awaiting a use!

[VK2XAX]

Tim, keep an eye out for old "Fluid Heads" that pop up on eBay etc.
Pan/tilt heads that have reached their end-of-life for professional camera work, but are perfect for parabolic dish aiming.

Hi Adam,

I subscribed some time ago and have watched your video on the Miller heads and I've had a saved search running on eBay for a little while now. I'm certainly looking to duplicate some of what you have built for dish mounting etc.

Your other video on the activity day is pretty cool too, the QSO on just the feed horn awesome!

cheers
Tim

[VK4GHZ]

I haven't tried this myself, yet, but if you have a 'dicky' resistive touch screen, this could be worth a shot.

Note that a hot air re-work station is being used.
These are essentially a fancy heat gun with better control over temperature and air flow rate, and, have various nozzles so that you can concentrate the heat when dealing with SMD parts.



https://www.youtube.com/watch?v=lP3ezWuh8uI

It would have been nice to see a 'before' and 'after' of the screens behavior - video production 101.

On my shack workbench I happen to have a Quick 861DW hot air re-work station, a handy tool for people who still like to make stuff with SMD components these days.

With it's fine nozzles, I find it's also very handy as a heat gun when heatshrinking individual small diameter wires and terminations.

As opposed to 'nuking' an entire area with the broad nozzle of regular handyman heat gun.

https://www.ebay.com.au/sch/i.html?_fro ... w&_sacat=0

And like Lou, I have also recently migrated to having a screen at a new desk specifically for assembly.
No more dead trees!

Schematics and datasheets etc can be displayed on the old laptop (which is across the home network), and board overlays etc are displayed on the [extended] Dell 21" screen.

This old screen doesn't even have modern HDMI or DP connectivity, so I used a $9 HDMI to DVI adapter lead for connection to the laptop. The screen has become useful once more!
https://www.umart.com.au/8ware-High-Spe ... 0476G.html

Just need to find a better spot for the old laptop to free up more desk space.

And once you use a 7" maggy lamp with the optional 12 diopter lens, you'll never go back to a regular 5" maggy lamp.
https://www.mektronics.com.au/daylight- ... -lamp.html

[VK3ALB]

Yes I know,

After my previous post on the HUGE panel meter, you've all written in complaining that you can't find one and you don't have anything similar in your junk box. So, I looked in the junk box and found a 40x20 LCD. Why not make a big volt meter out of that? The principle is the same, FSD = 1 volt. As always, the interwebby had an almost ready made solution for me.

The only gotcha, his display library references a i2c library. I tried to hack the code to drive the display without the i2c board but it's harder than it looks. Not impossible I'm sure but it distracted me from my task.

Take a good look at that screen. Each of those blocks is a 5 x 8 matrix. There are 40 x 5 = 200 columns of pixels in this display and the code increments one column at a time. This means the display resolution is 1 V / 200 columns = 5 mV per column.

The large prototype board holds the i2c interface at the left and Arduino Nano at the right. The small prototype board holds a negative voltage generator driven by a PWM output from the Arduino. This negative voltage is required to set good contrast on the display - forget the contrast control on the i2c board, it doesn't drive below zero volts. This negative voltage may not always be required but was for my display.

There are some changes to the original code related to scaling the input for 1 volt as well as the PWM for the negative rail generator, drop me a line should you wish to give it a try.

What, no 40x2 LCD in your junk box? Try Rockby and you too can have a very flash, wide screen, relative reading volt meter.

[VK4EA]

75% complete repackaged 6cm transverter now with a 10W PA stage and a sequencd DB6NT preamp at the feedhorn.

Hoping this thing may help set some more VK4 records this coming Winter.

6cm_front.png (77.33 KiB) Viewed 2005 times

6cm_top.png (71.26 KiB) Viewed 2005 times

[VK4EA]

5.7 GHz 10 W PA, feedhorn preamp, fully sequenced.


https://youtu.be/oBMSnczMWkk



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[VK3ALB]

Once in a while you realise there's enough bits in your junkbox to complete another project. Yesterday I completed a small 1296 transverter capable of 15W.

[VK4EA]

viewtopic.php?f=40&t=14037

[VK2XAX]

Just changing out the weird Band 3 connector on an EIP 588B frequency counter to an SMA. The old connector looks like and odd form of SMB but its not. Interestingly the newer EIPs and the C version come with an SMA in this position.

Now I just need to find an external mixer or two for the higher bands, These counters can read up to 170GHz !

[VK4YMB]

Finally boxing up my Eltek Flatpack2 48V power supply.
Added a LCD screen displaying: temperature in/out, current draw and voltage in/out.

[VK7HH]

Once in a while you realise there's enough bits in your junkbox to complete another project. Yesterday I completed a small 1296 transverter capable of 15W.


tiny1296.jpg

Very neat Lou. This mounted at the feed of a yagi for portable operation will work well!

[VK3ALB]

Thanks Hayden,

As I understand it should only cost me $1682 to test it in the field.

[VK4EA]

10 GHz EME setup progressing. Determined the focal point using W1GHZ HDLANT software. Theoretical 37 dBi of dish gain and 16 dBi feed gain, estimated efficiency of 57%.

The dish looks like it is oblong shaped like you’d expect of an offset, but it ain’t, it’s circular .... The existing side braces gave me a reasonable indication where to start. The dish looks like the satellite Internet links you see on rural homes so presume they feed it like an offset to avoid any blockage caused by the feed assembly.

The Alfa SPX-02 Az/El rotator is rated to 75 kg, total assembly weight including the counterweights is about 15 kg. Still to add is the DB6NT PA and transverter.

Now ready for some receive testing using Sun noise and the German beacon near my moon set.







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[VK2XAX]

Nice 10Ghz kit Peter.
How big is that dish ?
How much power are you going to feed it with?
cheers
Tim

[VK2XAX]

Testing the 150th VK3CV transverter board

122GHzTransverterTesting

[VK4EA]

Nice 10Ghz kit Peter.
How big is that dish ?
How much power are you going to feed it with?
cheers
Tim

Gidday Tim,

Thanks, just a tad bigger than the 122GHz kit I am looking forward to .

1 metre diameter dish, planning on 60 W, but, the exchange rate is making DB6NT devices much more expensive than I’m willing to pay.


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[VK4EA]

Quick little Sunday afternoon job.




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[VK2XAX]

Gidday Tim,

Thanks, just a tad bigger than the 122GHz kit I am looking forward to .

1 metre diameter dish, planning on 60 W, but, the exchange rate is making DB6NT devices much more expensive than I’m willing to pay.

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Yeah..... 60w at 10GHz is generally many $$$$ but there also seems to be a premium on top of that when buying DB6NT!

[VK7HH]

Quick little Sunday afternoon job.




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Nice one Peter, mine is built up, I'm just waiting to go and install it at my remote site.

[VK4GHZ]

K3NG Rotator Controller for satellite operations.

Anthony, K3NG, has done a fantastic job with his Arduino rotator controller project.
Github: https://github.com/k3ng/k3ng_rotator_controller

I downloaded the zip a few nights ago.
First evening for familiarisation, and starting to wire up between a breadboard and the Teensy breakout.
Second evening had full functional CW and CCW azimuth control using a 20x4 LCD and physical push buttons to control my Yaesu G-800DXA rotator via NPN open-collector transistors going to controllers remote port.
Worked a treat with SatPC32!

I'm using a Teensy 3.2, (my go-to microcontroller in recent years), rather than the Arduino Mega 2560, BTW.

Today the grotty old 20x4 LCD and push buttons were removed to make way for a Nextion 3.5" touchscreen.
Again, relatively painless to implement with some port I/O juggling around.

Next phase is to get elevation control running with a linear actuator, and that's where the eBay relay modules come in.
K3NG has provided for many options for measuring elevation.
Have a stash of LSM303 and ADXL345 sensors to experiment with.