What's on your Workbench?

[VK2XAX]

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

While I've used the Jaycar cabinets mentioned here, I'd like to know where the rack cabinet, Darrell mentions, comes from too !

[VK3ALB]

Transverter is progressing. Build on the back of a MTI 5.7GHz panel. Alu channel around the edges is needed due to the height of the pipe caps. The W1GHZ boards are easy to put together and work as advertised. Each block has been tested individually now all it needs is one last go over in the completed configuration to check the adjustments then a live test.

[VK2KYP]

Hi Lou, looks good.
I have had trouble driving the FPV amplifiers similar to one you are using. I have read there is a 16dB pad on the amplifier input that can be reduced to 10 dB reducing the drive requirement.
Have you experienced this.
73 Gary

[VK3ALB]

Hi Gary,

Yep that was mentioned in a post from me a few days ago. Expect a watt or so for 10dBm input. Chris VK3ACG cracked one open and did the mod. He did it with 0802 series resistors but it was difficult. He recommends using the smaller 0603 resistors.

The sellers are all very optimistic in their advertising about max output power and funnily enough my board has 5W printed on it. I doubt you could even get 2W from such a device let alone 5W - still they're cheap and they do have a bit of gain. Should be plenty for LOS paths.

[VK4CDI]

GD Lou, What probe lengths did you use on the pipe cap filters?

Phil VK4CDI

[VK3ALB]

Hi Phil,

Didn't keep notes but from memory they were all 8mm same for the multiplier.

[VK2FLR]

SG Labs
I have just received a box from Bulgaria containing a 13cm transverter, a small PC board 13cm antenna (free!) and a couple of plugs. Nothing else and no documentation at all.
Is this normal?
VK2FLR

[VK3ALB]

Yep normal. You can download the datasheet from the SG labs website.

Quite simple to set up and loads of fun. Note, the antenna is cut for 2300MHz.

[VK2FLR]

Thanks Lou. I will have a look at the website.
The usefulness of the antenna is that I can stick it at the mouth of my 1296 septum horn and the dish and check the local WiFi QRM problem if any. If it looks OK I will make up a septum horn for 13cm.

[VK2GFR]

From: VHF UHF Microwave - VK ZL Amateur Radio Pages.
2 December at 08:28
Not quite earth shattering operational stuff...
FYI (on the bench stuff)
Had some "me time" yesterday so I finished off my portable VHF/UHF "rack".
Mounted a Meanwell mains to 12V@10A SMPS at the rear, then rigged up the circuitry for battery power as well.
Directly wired the battery leads thru the cabinet at rear (have Anderson connectors) but time was getting away! (doesn't it always?)
And those mozzies in the evening...OMG!
BTW try some "OFF" spray it works at treat!!!
Saw the little buggers flying around but NEVER got bitten.
(a field day suggestion)
A bit of jigery-pokery with the physical wiring, but it's in and working.
An old pix but you'll get the idea.
Very satisfied I am.

[VK3YE]

Not the workbench but the ground.

Test was to show that a cheap handheld, some wood, some wire and an LED can work as a lecher line on 70cm and measure frequency to a 2% accuracy.

[VK3YE]

The most recent project. Tested on WSPR, with beacons and SSB DX.

[VK2FLR]

In the air actually.
I need a low noise 6m antenna to hear the South Americans. I thought I would try an LFA design to see how it goes. So far so good and plug and play 50 ohm match. The only problem now is the missing South Americans. Maybe 2019!

[VK3ALB]

Sorting through my junkbox today and what did I find?

Here's an example of a homebrew 23cm and 13cm transverter from the 1980's. This was based on a design by YU3UMV published in VHF-Communications 1986. The boards are fiberglass drawn freehand with a Dalo pen then etched. I count 23 x BFG96 transistors and a TP3020A in the 23cm PA.

There are two crystal oscillators (one for each band) running 30MHz and 32MHz crystal multiplied to 540MHz & 576MHz. Separate TX & RX converters take the appropriate LO and multiply for 144MHz in/out.

Oscillator and TX/RX switching is done with PIN diodes and is controlled by RF sense from what the author called a VOX board, not sequencer as we do today.

This builder removed some of the PIN diode switching and replaced it with a To Tsu (Tohtsu) relay. Next to the relay is a dual band stripline RF detector for reading TX power.

Just consider the effort and commitment both in time and dollars this fellow went to get on these bands. It's a lot different today.

I've posted this in several places basically for the sake of posterity because it will soon disappear from FB.

[VK3YE]

Quick & dirty vertical antenna for 6m

[VK7HH]

A couple of things on the workbench at the moment...

A DSE D-3800 power supply ready for 5 new 2N3055 regulators to be installed

A 3.4GHz VK3ATL panel modified with a sequencer to be wired in. Waiting on two more SMD resistors to arrive to complete the sequencer. The transverter is only doing about 125mW at the moment, so going to try removing one of the inductors in the PA as posted on here to see if the output will come up. Either way, it should drive a PA nicely.

[VK3YE]

Transmit a TV picture with a 1N4148 diode (and little else).

[VK2XAX]

Here is my Minikits 3.4Ghz transverter testing the TX chain.

I found it somewhat deaf so I'll add an LNA.

cheers

Tim

[VK2CSW]

So many things with buttons.

How do you remember what they all do?

[VK3ALB]

Yeah maybe I'll measure that supply voltage another time.