Category Archives: Station Equipment

Articles about Radios, Amplifiers, Tuners and related Ham Station Equipment. Fixed, Portable and Mobile Station Equipment Articles are included.

CW and QRP, Featured, General, Homebrewing, Newsletter, On The Air, Station Equipment

My SSB BitX-40 build from VU2ESE

Below is a photo of my BitX-40 kit from Ashhar Farhan VU2ESE in India with my very own custom designed case.  The kits are available from http://www.hfsigs.com/

The top cover shown is powder coated steel mesh.

BitX-40 Enclosure

The sheet metal housing was designed in a solid modeling software package called Onshape. This web based software is free to use if your designs are to be available to anyone who signs into an account.  This design is “in the cloud” and considered “open hardware”, available to anyone who would like to use it.  Below is a screen capture of my Linux desktop running Onshape within a web browser.

BitX-40 Enclosure CAD Design

With access to a CNC punch press and a 90-ton brake press, a coworker of mine helped out with a bit of “government work”!

I left out some of the detail in the housing to let others enjoy the use of a drill and allow for some creativity with a customized placement of components.

BitX-40 Enclosure with Board

Some of the wires are not needed but may be useful in future “hacks”. The image below shows some of the wires removed from the “Molex” connector.  A small sharp object can be used to push in on the barb to remove the contact for a future project.

BitX-40 Cables and Connectors

See http://bitxhacks.blogspot.com/

I used my sketch to drive the LCD screen and the SI5351 chip using the Adafruit library.  The checkered block moves left and right between the arrows to indicate when I am at or near the end of travel with the tuning potentiometer.

BitX-40 Frequency Stationary
Stationary

When I move the block all the way to the right with the potentiometer it turns into an arrow and automatically increases the frequency. To make it stop just turn the potentiometer to the left.

BitX-40 Frequency rising
Frequency rising

I like the ability to scan the band without having to turn a knob!

Below is an image showing 12v and 24v voltage regulators and electrical tape on the housing tabs.  12v is for the majority of the wiring and I used 24v for the IRF510 PA.  The black tape looks nice behind the black mesh cover.  while testing I measured about 4W RF output with 12v feeding the PA and 16W RF at 24v.

BitX-40 Enclosure

The bottom has extruded “feet” along with stick on feet to keep the rig from sliding.

BitX-40 Enclosure

I used an SO-239 connector for the antenna.  I saved the BNC connector from the kit for test gear.  The red terminal post is connected to 32v from a repurposed HP printer power supply.  The barrel jack is connected to 16v from the same supply.

For more information on the case, you may contact me through my QRZ page.

73,

Mike (AB1YK)

Activities, Antennas, Featured, General, Newsletter, Space, Station Equipment

A Portable Satellite Station Part 1 – A Simple Station for AO-85

Our club has quite a few members who are interested in space communications. We decided to build a simple portable satellite station last year for our 2016 Field Day operation to learn about satellite communications and to create something new for folks to work with during 2016 Field Day.

Simple Portable Satellite Station
Simple Portable Satellite Station

Our 1.0 Portable Satellite Station was a relatively simple setup built around an HT, an Elk 2m/70cm satellite antenna, and some gear to improve the receive performance and transmit power output of the HT. All of the gear was mounted on a board to make it easy to transport and it is powered by a LIPO rechargeable battery. The gear in our 1.0 station is made up of the following:

Improved Portable Satellite Station Antenna Support
Improved Satellite Antenna Support

Our first contacts with our 1.0 station were made using the Elk Antenna hand-held. Later, we created a “plumber’s special” setup with a camera tripod to make pointing the antenna easier. Note the angle meter from a local hardware store which measures the elevation angle of the antenna.

AO-85 (Fox-1A) U/V Mode FM Cube Satellite
AO-85 (Fox-1A) U/V Mode FM Cube Satellite

This setup worked great for making FM contacts through AO-85 (Fox-1A), a  U/V mode FM EasySat. We used the 1.0 station on multiple occasions including Field Day 2016 and several of our club members used it to make their first satellite contacts. The Full-Duplex HT allowed us to hear our own signal coming back from the satellite which was an important tool to help with aiming the antenna properly. The ELK Dual-Band antenna is also a good choice because it uses a single feed point and a single polarization for both the 2m and 70cm bands.

Portable Satellite Station Team Operating Approach
1.0 Station Team Operating Approach

We used the team operating approach outlined above. This worked especially well for new folks who had not made a satellite contact before as it enabled each of the three team members involved in making the contact to focus on a specific part of the contact. We used orange plastic tent stakes to make AOS, Time of Closest Approach, and EOS to mark headings for each satellite pass. Small flashlights used at the stakes made them glow for night-time passes.

We certainly had a lot of fun with our 1.0 Satellite Station and I expect that we’ll continue to use it. As we gained a little experience with AO-85, we decided that we wanted to build a more capable Portable Satellite Station which we could use to operate with linear transponder satellites and which included a tracking system and better antennas. I know from experience with our home satellite station that DX contacts are possible using higher altitude linear transponder satellites like FO-29.

We would also like to be able to use APRS and other digital modes through satellites as well as receive SSTV pictures from space.

These goals have become the basis for building our Portable Satellite Station 2.0. More on the new station in Part 2 of this series. Other articles in the series include:

You may also be interested in the satellite station at our home QTH. You can read more about that here.

73,

Fred (AB1OC)

Education and Training, Featured, General, Newsletter, Station Equipment

January Tech Night Making the Most of Your HF transceiver

The January Tech night was about getting the most out of your HF transceiver. Fred had an interesting  PowerPoint presentation where he demonstrated how to do just that. For anyone else new to HF, I wanted to comment on it here. In his presentation, he described how you should use filtering first and digital signal processing (DSP) as a last resort. That’s the exact mistake I was doing. if you use a lot  DSP with a narrow filter selected the audio sounds hollow and really difficult to listen to. If you turn off the DSP  select the narrow filter and then bring up the DSP if needed you get less noise and a pleasing audio output. Also turning down the AF gain can be your friend too!

73 and good DXing

-Jim.   K1BMR