Hello,
over time I have been working towards a small EME station, one aspect has always presented a hurdle, how to move the antennas slowly enough to track the moon without over shoot of direction control. As normal motors need time to spin up and spin down there is generally some degree of over or under shoot of the mark.

I have a rather large and unique gearbox /rotator that came from a VK3 back in June, it was advertised on VKHAM and is a made by a US company called: Houston Fearless

Will post a photo or a link to it soon.

This thing stands 1.2 meters tall and has 900 x 900 mm footprint, it uses a very large worm drive to create rotation and had a 100V AC motor to provide the grunt (reverse the field connection to go in reverse). While testing its operation it became apparent the speed was a bit fast for my liking and even though it used a magnetic brake to reduce over run it still was hard to be accurate with it like this.

I have always had stepper motors in the back of my mind to be the motor for a rotator on my EME system as they can be pulsed to provide small known steps in rotation and hence provide small increments of azimuth BUT now comes the crunch, have others out here in the blogeshpere had any real world experience with these beast as to how much torque they can generate or are they gutless beasts not suitable to drive a gearbox?
Regards,
Peter, vk5pj

Question for those that have been there, done that.....

I am almost ready to replant a 13.7m Nally tower. I am trying to sort out an issue that I came across with information in the computations book.

The original instructions call for a hole 381mm diameter, 3m deep. OK, fair enough, these are dated 1977. However, also included is an additional sheet dated 1983, which states 381mm diameter, 2.4m deep. We are not in a sandy soil area, fair bit of clay and shale down lower.

Question 1; Which hole depth is correct?

Question 2; Those that have been down this path previously, did you include a quantity of mesh or rebar in your concrete?


Ron
VK4BVI

Greetings all.
lets continue on with the experiments on 23cm EME. As you may know there was a long running thread exploring all aspects of setting up a moonbounce station for the quiet 23cm band on the old forum.
23cm is totally different to 2 metres. You can clearly see the trace of the station you are working, and there are very few spurious signals to cause confusion. Noise is very low.
So, who VK stations are experimenting at the moment?
Tonight there was VK3WRE, VK3NFI and VK4UH operational on 1296.075 working me. Dish sizes ranged from 2.5 to 3 metres.
Ralphs signal was audible at -16 and he has a 2.5 metre dish and 100 watts into a septum. Dean was struggling without a LNA at the feedpoint and got the occasional synch but no decodes.
Kevin is working on optimising his feedpoint position. Tonight he was quite a way off the optimum and nothing was heard, but at its previous spot he was only 3dB down on Ralphs signal. He had previously also worked Victor UA9YLU on his first active evening.
Another regular is Phil VK4CDI who has a good signal from his large dish. I get him at -13
In June we had Andy VK5FA doing some experiments and he was -19 using a 2.3metre dish.

We use JT65C for the time being, but there is a new mode out now that we may all move over to.

Equipment.
G4DDK VLNA2+ low noise rx amps are the go, vk5eme Preamps are good too, but need plenty of absorber material to tame them when mounting them in a box.
W6PQL amplifier bricks or the european types are the most used power amps. I have an Alan Devlin 160 watter here and a W6PQL 4 block.
Mount the LNA at the septum feedpoint , and mount the power amp at the back arms of the dish, or at the base of the mast piece (ground mount).
Radios used are IC910h or IC9100, some use transverters. Lock everything to GPSDO or a OCXO. The high stability option for the IC910h is good.

Software , use Joe Taylors WSJT. also use vk1od Owen Duffy's NFM program to do accurate sun noise vs cold sky measurements to optimise your antenna setup.
The best website to see realtime moonbounce activity on 23cm is HB9Q.CH, its where we hang out when actively running our stations to coordinate etc.
More info to follow
73 Dave vk2jds

the start of this thread really starts here, so please have a read to get any needed background

http://www.vklogger.com/forum/viewtopic....974#p61974

So last night all the stars aligned, the new FET had arrived, I had been practicing with the hot air soldering station (elcheapo from ebay) so it was time to push back my aprehension and just DO IT.

Cleaned up the PCB, freshened up the solder tining on the heatsink and the under side of the PCB and then put them together with some BIG heat. Now this is while they are still OUT of the 910.

Have let it all cool down and checked that the pre-driver board is now attached the small heatsink.
Tin the underside pads of the new FET

*-Caution-* Exisiting capacitors and larger resistors on the board do start to become mobile with the hot air gun, so be careful where you point it

Now time to get the assembly back up to temp by blowing air from the top on the exposed section of the heatsink that pokes through the board. check at intervals to see if it melts som fine solder (air gun removed) then once confident it is hot it is time to introduce the FET and keep the heat on while its pads take the solder from the PCB, I added a small amount of fine solder to ensure it was all flowing.

Let it all cool down again.

Put the board back into the 910, I used the hot air again to get each side of the board to slide down the header pins by waving it back and forth and a small amount of pressure from a fine tool.

Put the securing screw back in to mate it all up to the main chasis and BEFORE you tighten it up, wave the hot air across the header pins to make sure it is all home, then tighten the screw, you can repeat this a few times if unsure.

Okay, here is the reward, straight to 70cm on FM tx and there was 70W on the external power meter and it did not waver one little bit. At this point I stopped and went back to the house to calm my nerves, more extensive testing later.

I have some photos I will contribute later on,

Peter, vk5pj

Kuhne seem to be going through a process of product renewal at the moment.

New products of interest (to me, anyway) include:
MKU 10 G4 http://shop.kuhne-electronic.de/kuhne/en...?card=1683
- 10 GHz transverter with switchable 2m/70cm IF, inbuilt TCXO and lockable to 10MHz. It's about 50E cheaper than the previous model (G3)

MKU 47 G2 http://shop.kuhne-electronic.de/kuhne/en...?card=1611
- 47 GHz transverter with integrated 2m IF switching, sensitive Rx and typically 60mW output. A separate LO is required and the Elcom 1201 matches nicely.

They are also having a sale of an extensive list of equipment: http://shop.kuhne-electronic.de/kuhne/en...ial-offer/

VK can't purchase directly through their web store (yet). Send an email to <!-- e --><a href="mailto:info@kuhne-electronic.de">info@kuhne-electronic.de</a><!-- e --> and request a quote.
Note that the prices listed include the German 19% VAT which we do not have to pay.
Also, if you're happy to wait for delivery, ask about cheaper shipping options.

I have no connection with Kuhne, financial or otherwise, apart from being a very satisfied owner/user of their equipment.

Regards,
Dave.

Some may remember on the old forum there was a post about the WIA's proposal they submitted to the ACMA, there was a link inside one of the messages in that post that listed the WIA's detailed proposal. Here is the link :-

wia.org.au news item

As this effects us all, and is of fundamental importance, any update or information would be great.

How hard can it be? You order a component and it appears in the post then you finish your project.

Some time ago I ordered a number of RS485 SOIC package chips from a supplier I had never used before. What arrived in the letterbox was DIP package chips which are totally unworkable for my application. After the initial frustration and shouting at the computer I contacted the supplier and explained the situation. No drama, they sourced a suitable replacement (now I know why I didn't get the original ones I ordered) and sent them to me. They didn't argue or want the DIP packages back.

Yes, they should have sent the right parts in the first place. Yes, they could have told me they were having trouble finding the part I wanted. Yes, they are obliged to send the correct parts or at least offer a refund if they can't supply. They could have ignored my complaint. They could have asked me to send back the other parts. They could have refused to sort out the problem.

In the end, it took 2 emails and a two week wait. Nice one Futurlec, I'm happy with the result.

Hi all

I made a reproduction Kingsley AR7 speaker for a special display on this iconic WW2 receiver at the Townsville RAAF Heritage Centre (formerly RAAF Museum). It looks kind of OK but I would really like to get an original one. Does not need to have the innards just the case would be fine. I put an ad on the classifieds site but no luck.

73

Wayne VK4WDM

Sunday October 23rd will see the next 23-on-23 MAD for 2016.

I'm getting in early so hopefully a more few stations will be able to plan their /P operations well ahead of time. And with this weekend's Winter VHF/UHF Field Day potentially a wash out, it may provide an opportunity to reduce the $/QSO rate of the uWave gear

It's now become common practice, that where the 23rd falls on a weekend the events operating time are shifted from the evening to a day-time activation event. This has also allowed operators to take full advantage of the time, and head for the hills to trial their /P stations, investigate new paths and hopefully complete a contact with a new station (or more) that they wouldn't normally from their home station. It also provides an opportunity to activate other uWave bands. :o

A suggested schedule:
2:00pm (04:00z) - 03:00pm (05:00z) 23cm SSB/CW only
3:00pm (05:00z) - 5:00pm (07:00z) 13cm and other uWave bands

Liaison -
147.000 Repeater (if the RDRC would again be happy with that)
40m - 7.150MHz (is that still the recommended QRG?)
Mobile/cell phone
VKLogger iChat '23&Above'

As a number of 23cm Plus operators do not participate in the OzLogger forum, please let those who may be interested know by taking a moment to share the plans with them.

However to allow others to plan their participation, could you please advise your interest, availability and any suggested enhancements to the schedule in this thread? :!:

Over the years I've seen many projects expounding the virtues of the J poles & Slim Jims. At first these appear like a simple and easy way to get on air but are they really?

Both can be made from copper or aluminium tube or even balanced line but they seem fiddly requiring far too much work for my liking. Their sturdiness is directly related to the builder's mechanical skill and in some cases they're awkward to mount. Many will say that the versions built from balanced line are great because they can be bundled into a pocket or bag - perhaps so. Some claim they are a cheap way to get on the air - probably but I think there is a better home brew antenna. Many hams still suggest the J pole or Slim Jim makes a good antenna for the newbie. There was even an article in AR recently.

The flower pot antenna has been around for a long time and is nothing new yet it doesn't seem to gain the recognition it deserves. It doesn't matter what your skill level one flowerpot is as sturdy as the next. They cost well under $20 to build. You can cut away most of the PVC pipe and roll it up for easy transport an deployment and they are almost indestructible.

They are not a DX antenna but compare well against the lower range of Diamond X series antennas. For the price, there is no question the flowerpot gives you more bang for buck. Pack one with a $50 Chinese handheld and you have a very capable portable station for someone just getting into ham radio.

Isn't it about time we bade a fond farewell to the J pole and Slim Jim?