VK Logger Ham Radio Forum Archive

I used an XV-144 with a K3 as well. I measured the Noise Figure as 8 dB (I think) that I thought was not brilliant. I might have messed up the construction. They could be available second-hand as Elecraft has since released a 2M transverter as an add-on board within the K3/K3S. I ended up designing ...

You should be OK with your current arrangement. Conditions have not been real flash over the last couple of days. Stay with it! Keep in mind that local topography can have an effect (eg a hill near you on the direct path), so sometimes the direct path is not the best. You can use the Op Info facilit...

I built a MiniKits PGA-103 amp that met the gain specs for the device at 2 M. Didn't measure IP3. It needed a front-end filter to kill IMD noise but I'm only 10 km from Canberra's TV/FM transmission site. I haven't managed to destroy it yet. I killed several devices in DIY circuits. They seem more r...

On the LEA-6T, it would be worthwhile checking out discussion, etc, on the timenuts forum. Google "timenuts ublox". There is also some good information through the Ublox site. This cuts into some heavy stuff. I chickened out and bought a PicoSync on eBay that was usefully cheaper than a Th...

Wayne

What length of rod do you need?

There are fibreglass electric fence posts that are about 10 mm diameter, but seem to be 1.5 M max length. Pretty cheap from your local rural supplies outlet.

Dave

Sorry, Jayson.

You don't need an antenna analyser good for 432 MHz. VF isn't dependant on frequency. You can use any analyser. In fact using a lower frequency will give you greater precision.

Dave VK1DJA

Jayson

Best to measure the VF of the pieces that you have. The word on the street is that VF can vary batch to batch.

If you have an antenna analyser good to the working frequency, or have a friend to have one, it's easily done.

Dave VK1DJA

LF Today (RSGB publication) uses T94-2 for cores for a 500 kHz low pass filter. It says the maximum power level is about 100 W, set by the cores and the wire size used (0.56 mm in their design). Mini-kits has a good range of cores, as possibly do other suppliers. The LF Today design, BTW, is a 7 ele...

Given that the legal limit on 630 M and 2200 M is given in terms of radiated power, there is the question of what is output power from a PA that, coupled with an antenna of reasonable efficiency, is needed to reach the legal limit? My reading is that a good antenna setup on 630M will not be above 5%...

Erwin As an Elecraft K3 user for a few years now, I don't believe there is an Australian distributor. There certainly is one in Japan and re-sellers in Europe. Perhaps the KX3s that you heard about on the air were bought pre-loved. Elecraft support by email is excellent- replies same day. I wouldn't...

Hi Wayne,

It's a 7.6 MHz crystal. I haven't been unable to find a source in Australia. Nearest was 7.68 which would be just outside the band.

But they are cheap from the QRP Club, for members only.

Could always get a 7.6 MHz crystal custom-made, of course.

Dave

Wayne

74HC4060 is a pretty common device. You should get change from a dollar. Try an outfit like RS Online or element14.

The trick, unfortunately, is finding a crystal with a frequency able to be divided by a power of two down to the range 472-479 kHz.

Dave

Another scheme is to use a microcontroller like an ATTiny25 or 85. This can generate (with parameters set in code) a signal dervived from the clock in turn set by a cheap crystal. An example (a beacon for 136the kHz band) is described at http://www.vk1od.net. A book I've found very helpful is the RS...

Congratulatiojns, Brenton. A very creditable piece of design. In amateur circles, I hope it gets the recognition it deserved for extending Tayloe QSD above the 21 MHZ or so that has been taken as a limit. And that the examiners like it too. I'd like to hear more about the devices you've used in the ...

Ted Often the datasheets give parameters over a range of frequencies, perhaps with some extrapolation. I've been looking at the ATF54143, which suggest that the NF is lower down in VHF. The Avago website has some material on designs for VHF applications. This was done partly as a sanity check for a ...

I use Eagle too. I use a low-cost laser printer to print the artwork to paper or polyester sheets and a homebrew exposure box. Works well. There is a learning curve to become familiar with Eagle and achieving reliability in the developing and etching needs some patience. Becoming able to design and ...

You might like to check out the web site of Owen VK1OD. One of Owen's topics is a beacon for 136 kHz. A single ATTiny 25 chip generates the QRSS sequence (callsign, etc) at the desired frequency. Component cost under $10 or thereabouts. $50 or so for a programmer is still inexpensive compared to mos...

I've used RF Suppliers twice now. Quality is fine. Service is very good. Comprehensive range.

Dave VK1DJA

I've found solder paste works well and gives a neat result (if you use a light touch on the syringe to put down a small dab). It does mean that you can then use one hand to place the component and keep it in place and the other to hold the soldering iron. I haven't needed to use flux as well. With a...

I think the Dell D630 is a laptop, so that you'll be looking for a USB sound card, rather than PCI or PCIe? Check out the sound card page on the website for Telepost Inc. The E-MU 0202 is one of the more popular for SDR used for spectrum scopes because it gives a 200 kHz slice of a band. The 0202 ha...