Month: March 2017

Messi & Paoloni Ultraflex 7 coax cable

Messi & Paoloni Ultraflex 7 coax cable is being marketed as similar to RG-213 in performance, but 7mm overall (against 10mm).

There is lots of comment by online experts questioning the claims, and critical of things like the braid coverage, copper foil etc, but without real evidence that it does not live up to specification.

Accepting the specifications for Ultraflex 7 and Belden 8267 (B8267, RG-213) for a moment, how do they compare.

Let’s take the loss factors calculated for TLLC and de-construct the conductor and dielectric loss for each line type.

Above is a comparison of the cables. Continue reading Messi & Paoloni Ultraflex 7 coax cable

Last update: 5th March, 2017, 10:09 AM

WSPR checkout on new workstation

I have been building a new workstation and a simple test of its reliability for logging signals via the IC-7300 sound card is to run WSPR.

So, WSJT-X was configured for WSPR on 40m and run for 24h using the low G5RV inverted V dipole with tuned feeders (designed primarily as an NVIS antenna for local contacts).

Above is a map of the spots involving VK2OMD over the 24h survey. Continue reading WSPR checkout on new workstation

Last update: 6th March, 2017, 12:43 PM

DS18B20 input for the generic heating / cooling controller

The generic heating / cooling controller (hcctl) is a flexible bang-bang thermostat controller based on an ATTiny25.

The project has been expanded to accept a Dallas / Maxim DS18B20 1-Wire temperature sensor. The DS18B20 produces a digital output (signed sixteenths of a degree) has a range of -85° to 125°, accuracy of about 0.5°, and costs a dollar for bare chips, a few dollars for an encapsulated probe.

Above is a development prototype with the DS18B20 being heated by a small incandescent dial lamp to test function.

Continue reading DS18B20 input for the generic heating / cooling controller

Last update: 2nd April, 2017, 10:11 AM