Messing about with microwaves – eBay Eyal Gal 6 Ghz transceiver unit…

Now that the propagation on 40 meters has deteriorated after the winter months, with weak, watery signals the norm rather than the exception, my radio activities have swung to my other love, Microwaves!

I’m keen on the world above above 70 cm, and have been active in a lot of the WIA field days over the last few years. I have equipment for 2.4, 3.4 and 10 Ghz. the 10 Ghz is a Kuhne G3 unit purchased from Germany when the exchange rate was favorable with the Euro. The other 2 bands I constructed from Minikits Kits, from Mark, VK5EME.
A typical field day sees me often heading over to Yorke’s Peninsular, to the west of Adelaide to work the other stations in the contest, either those out and about “Roving”or other portable/home stations. I usually have all bands from 2m to 10Ghz except 5.7 Ghz. The contest is a lot of fun, and it’s a great weekend away for me and all my gear!

I decided to rectify my lack of 5.7 Ghz and look what was out there, either kits or ready made. The short answer is not a lot…Kuhne do their lovely G3 for 5.7 with 250 mW output for a price and there is the cheaper VK3XDK kit option but with roughly only 10 mW output…so you need the added expense of an amp…either way was looking expensive by the time you add all the extras like a PLL unit for the LO and then putting it in a box and making it pretty…As I was on a budget I needed to come up with something cheaper.

A few eBay sellers from Israel ( why is this country the RF surplus capital of the world?) have been offloading a fair bit of surplus Eyal Microwave Industries (EMI) gear, in the form of TX RX modules for several Microwave frequencies of interest to radio amateurs. The 10 and 11 Ghz units have been popular and Roger, G8CUB has a webpage with information on getting those units going, as well as details of units for other bands…

My interest picked up when I saw that there were units available from several suppliers that are listed as being on a frequency of 6Ghz, very close to the 5.7 Ghz amateur allocation in the 6 cm band…The price was right, so I decided to grab one, even though the info link in the auction was dead and I couldn’t find any info on the internet about them. I figured for the price, it was worth the risk, and if I could get the thing to play then I would be saving a lot of money, as I found out through extensive searching that these units had an output of over 1watt (31dBm), perfect for a field day rig.

The unit as it arrived from ebay…

I wasted no time in removing the back off the unit to discover what I could. I was keen to at least get some idea of the pinouts of the interface control connector. Thankfully, it was clearly marked…

In the mean time, Derek VK5RX, kindly sent me a PDF of the specifications he had found after talking with him when he rolled up at my recent Spring Field Day site at Kline’s Point, over on Yorke’s Peninsular. We had been talking about the 10Ghz Eyal Gal units as well as this one, and he was able to find the very document I had been searching fruitlessly for and send it to me!

Power Connector sorted…

After the reading the specification PDF, I was a little dissapointed. It seems these units are might or might not work, as they are designed for  6.5Ghz to 7.15Ghz. I sent the specification PDF to Roger G8CUB, and he seemed to think the same thing, but it still would be worth persuing…

I’ll still be trying to get it going, might possibly work with a 433Mhz IF but I’ll probably have more luck with a 1296Mhz IF.

Meanwhile, I’m waiting for a little -5volt module to complete the power supply requirement to the unit…

MORE TO COME…

Update 27/11/2013

Often, when building up projects, the actual item itself is relatively painless and goes together quickly and without hassle…however, Ive found that building the actual transverter itself is the easy part, its putting it in a box and wiring it up!!!

I live by the motto “never throw anything out” to a certain degree…and for this project, I have magpied just about all the things I’ll need to put the finished transverter in a box

With this Eyal unit, the power/control connections are via a molex connector, a rather small 6 pin job that I wasnt going to solder to.

The matching plug was available online, but by the time I purchased a minimum of 10 and added pins, it was close to 25 bucks delivered. Sorry!

My “never throw anything out” mantra paid dividends! In my box of wire that I keep from old copier/printers that I  rob at work before they go to the recycler I was able to quickly locate a loom with the correct plug on it with colour coded wires…problem solved!

I’m now waiting for a couple of bits to complete the power requirements for the unit, I’ll then be able to fire it up and see if it works…

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