W5TSU

For the W5TSU.net:8030 receiver I build a broadcast band filter. This should front end overload and intermod created by these stations and allow for better Ham band receiption. I also wanted to learn how to build my own coils.

I found a design at the vk3il blog. This filter was modeled with the ELSIE (free version). It is a 7-pole Chebychev filter with cutoff frequencies of 1.7MHz.

I started by winding some coils from 22, 26 and 30 awg magnet wire. I use a MingHe model LC100-A meter to masure these coils. I found holding the coils with my fingers didn’t make a sizeable different in the coil. What did make a difference was how tight the coile was wound and the lingth of the wire used. The size of the winding did make some difference but not as much as the amount of wire and how stable the winds where.

I’m working on the design of a APRS Tracker transmitter. The dream is a self contained radio transmitter, modem, and controler with a bluetool connection to a tablet running Xastir.

There are lots of designs and APRS Trackers. Some are almost what I’m looking for. Many are out of date or the designer is dormant. The bigest example is MicroModem. Wounderful design from 2014 but the deveoper is… In his how words… “Long Time, No See”.