What's on your Workbench?

[VK3YE]

Variable inductor from corflute material - in this case used for a QRP antenna coupler

https://www.youtube.com/watch?v=NyKu0qKVA1I

[VE2OLM]

Building some 2.4 and 5.7 transverter from KUHNE

[VK1JA]

Work is slowly progressing with the 23cm LNA and 13cm transverter/lna projects.

The 23cm and 13cm lna's will be mounted in a carrier class enclosure. The 23cm lna is a G4DDK type with the 13cm lna being a minikits version. I've left space in the enclosure for either a pair of 2m/70cm lna's, or if I have space on the mast, a 9cm transverter - there're rumors that SG-Labs may be bringing out a 9cm transverter in the future!

The 13cm transverter project is based on the SG-Labs transverter, and will be run through a 30w pa from PyroJoseph (ebay seller), and all mounted in a 2RU rack case from Jaycar.

Both projects are waiting on parts to come in the mail - the mast mounted lna's just need two of the small 12v-24v buck boost boards (buying the locally means 5x the price) and the 13cm transverter is waiting on 2 DPDT realy boards to deal with the PA and LNA switching. All parts are on the slow boat from China so they might be here by mid October Does anyone have two of the 12v-24 buck boost modules they want to sell at a reasonable price?

[ZL3RC]

This is a pic of the revamped ZL3TEN and ZL3SIX beacons.
Not on the work bench but it was while I was building it up.
Top down:
ZL3SIX exciter which consists of a Tait 162 TX section, cut out using a Dremel and a cutting wheel, modified to run on 50.040Mhz. It will generate about 45w flat out but is sitting at 25w to save power.
It was tuned for best power out efficiency which resulted in a figure of around 50% over all for the complete exciter.

ZL3TEN PA which is an old 27Mhz CB amp converted to class C capable of around 100w but currently running 25w

ZL3TEN Exciter which consists of a QRP-Labs TX kit to a small driver amp. This Exciter is very flexible in the modes it can generate and if you haven't looked at these as a beacon exciter I suggest you do as they are very cheap and you can even be GPS locked if you need too.

Two 12v SMPS 20A 1U high power supplies, only using one at present, side by side on one rack tray.

Power management panel with Voltage and current monitor on the left with a mains breaker and power meter, we have to pay for the power used, on the right.

The cabinet has a 230v temp controlled fan on the top and each PA has its own temp controlled cooling. The temp controlling of the cooling fans is to cut down on power consumption as left on 27/7 it just adds to the power bill unnecessarily.

Roger ZL3RC

[VK5ZD]

Rebuilding my 122GHz transverter into a new enclosure.

[VK2AAK]

Currently a mostly resurrected FT-726R. The unit is working but there is still some capacitor replacement to go as well as some final alignment. It's not bad though ... hearing the Dural (NSW) 2m beacon over a 235 Km path with just a 4 element yagi which is cut for the top of the band.
Also an IC-202 sitting on the bench waiting patiently. Again all working but waiting for an alignment.

FT-726R current project

[VK3YE]

Changing a quartz crystal's frequency with sandpaper



And attacking a ceramic resonator

[VK3YE]

Horrendously inefficient but it works

[VK3ALB]

Nice one Peter,

You've woken us from our slumber. I don't get much time in the shack any more but I still enjoy building when I can.

Here's the starting stages of my W1GHZ 5.7GHz and 10GHz transverters. The plan for these is to make a small portable system with not much power but easy to deploy in the field. I have panels for each. Note, the NBL310 devices for the 10GHz board are globally in very short supply but MiniKits are waiting for stock - perhaps December. There's not a lot out there for these bands unless to look at Khune or Demi but only cashed up VK4's can afford them.

If you want to go down this path I suggest you also order the mixers from Paul when you order the boards. The 10GHz system with caps, mixer, MMICs owes me less than AU$100 so far. I think that's a good risk when you look at the other options.

[VK1JA]

Hi All,

This is my first attempt at a BPF for 13cm to try and block some of the noise I have around here.

The LNA I have is the Minikits 0.05-3GHz low noise pre amp and very broad banded, and it looks like it may be overloading the front end of the radio with all the nearby wifi and other crud floating around.

Note that I had a 6dB attenuator inline, so the through loss is about 2dB at 2403. I purposefully tuned the filter low, so 2403.150 was just over the edge so that the wifi channels would be attenuated as much as possible. I have plenty of rx gain to play with.

I’d like to get the skirts steeper, and after playing with the tuning the only way I’ll be able to achieve steeper skirts is by putting another tuning screw in. But I’m wondering if I can just put an extra tuning screw in the middle like what W6PQL has done here in his 3 pole version (scale it down to 13cm) – http://w6pql.com/images/23flx/flxnotes.jpg

This one I’ve made is based on W6PQL design here - http://w6pql.com/13cm_filter.htm

More playing to be done!

Jayson

[VK2XAX]

2.4Ghz transverter nearly done.

Here is my Spectrian Amp board with 40w@2.4Ghz on 13.8v@3.4A

More photos of my transverter in progress here...

https://photos.app.goo.gl/4mVCWhHF8yfzTSbR9

[VK2LK]

This weekend I opened up a brand new desoldering station that was a gift from another HAM.

The board I am repairing is a FPGA debug board that I want to use for some development and testing work.

[VK3ALB]

The other day I received my 5.7GHz AV transmitter from eBay. The description says 3.5W/4W but I think that's somewhat optimistic according to the spec sheet.

Under the bonnet there is a pair of SE5004L 5GHz amplifiers in a hybrid combiner. The chips are rated at +26dBm @ 5V for +6dBm input. Output for 1dB compression point is 34dBm.

Interesting that each chip has a RF detector that puts out 1V for +27dBm output. This output is available at the little gold pad next to each chip.

There is also a 16dB attenuator at the input. Changing it to 10dB means you can get about 31dBm for 10dBm input.

I had to change out the reverse SMA connectors on the board and that's it. A working PA. It's mounted on a little fan but I think I'll scrap that for a block of aluminium bolted to the chassis.

[VK7HH]

Working on the VK7HH/P remote station upgrade.
http://hh.vk7.com.au:82/blog/index.php? ... id_post=42

Borrowed SG-Labs 23cm transverter and 30W Down East Microwave amp. Took a bit of fiddling but finally got 33W out of it.
Looking forward to working some decent DX this season on the higher bands.

W6PQL sequencer built and tested. Minikits relay to switch between RX/TX on the transverter/amplifier. IP switch to remotely control everything at the site. Not pictured in photo is 240V relay box to turn off rotator control box when not in use.

[VK4MIL]

2.4Ghz transverter nearly done.

Here is my Spectrian Amp board with 40w@2.4Ghz on 13.8v@3.4A

More photos of my transverter in progress here...

https://photos.app.goo.gl/4mVCWhHF8yfzTSbR9

I have one of these I would love to use but I have heard that they are not very efficient how did you get yours to work that good?

[VK2XAX]

I have one of these I would love to use but I have heard that they are not very efficient how did you get yours to work that good?

I haven't done anything special to it. I set it up on 26v first and then just run it at 13.8v

These amps are biased AB out of the box. Pyro's instructions make them class A

I reduced the bias a little so its more AB than A. This also brought it back to 40W which is what I wanted since my antenna can only handle 50W CW max.

I'll be doing further tests to to ensure its output is clean and it will have a 2 pole cavity filter on its output to ensure any nasties are way down.

regards

Tim

[VK4UH]

Nice one Peter,

You've woken us from our slumber. I don't get much time in the shack any more but I still enjoy building when I can.

Here's the starting stages of my W1GHZ 5.7GHz and 10GHz transverters. The plan for these is to make a small portable system with not much power but easy to deploy in the field. I have panels for each. Note, the NBL310 devices for the 10GHz board are globally in very short supply but MiniKits are waiting for stock - perhaps December. There's not a lot out there for these bands unless to look at Khune or Demi but only cashed up VK4's can afford them.

If you want to go down this path I suggest you also order the mixers from Paul when you order the boards. The 10GHz system with caps, mixer, MMICs owes me less than AU$100 so far. I think that's a good risk when you look at the other options.

caps installed.jpg

Ooooh Ouch!

[VK2BLS]

Hi all,
Looking at a possible 13cm PA project and need a suitable enclosure to fit all the gear in.
At the moment looking at a Jaycar 2 Unit 19 inch Rack style, but prefer the looks of the alum enclosure in pic.
Any ideas where to source this enclosure or similar ?

Darrell vk2bls

[VK3ALB]

Hi Darrell,

Are you locked in to using a rack case? If not, Jaycar sell a really nice instrument case which holds a lot of stuff. I put a shelf across the centre of the box and build on both sides. A cut-out in the top of the case allows me to mount the PA through to a big heatsink. See the pic on my QRZ page and a view inside my 2.4GHz transverter. Edit: This link is a bit funny, you may have to scroll down a couple of entries to see my post.

[VK3QI]

Darrell,

Jaycar are running a 15% off on that enclosure that Lou suggests.

I have used many of these enclosures for a variety of projects and by the nature of their construction, they are extremely flexible.

Just make sure that the front and rear panels are well earthed to the rest of the chassis.

Cheers

Peter VK3QI