Homebrew projects

In its by-laws, the HTC states its club goals as promoting telegraphy as well as promoting homebrewing
Even back when the club was established it was recognized that the combination of radios with minimal technical effort and expense would lead to good successes in the use of telegraphy.
Through a common goal in wanting to build a certain piece of equipment, the HTC attempts to encourage and support interest in homebrewing (a privilege given to licensed radio amateurs). There is a much higher chance of getting a piece of equipment to function properly if there is a broad exchange of information and experience and providing mutual assistance Among its members, the HTC has many very experienced electronic designers and specialists who are happy to lend their knowledge and laboratory equipment for common projects. The following describes some recent and past projects, and with this we also ensure documentation about them remains available. In the last few years, the QRP Party (often involving homebrewing) has often been organized together with other organizations. Get some impression 22xtimes QRP-Parties (in german) watch at the pictures.
Members from outside Switzerland can, when appropriate, also profit from the collected equipment documentation. In case of problems with a piece of equipment that has been built as part of a HTC group project, we will be happy to lend our support and experience. contact

MA-12 Project 

The MA-12 transceiver is a small 40m unit consisting of fewer than 100 components but is nonetheless very high performance. It was developed by Peter Solf DK1HE for the MAS (Minimal Art Session) contest.  Rules and further information are available in the attachments. The radio can also be used for other activities such as SOTA and standard QSOs. The project was initially presented to HTC members at the QRP Party on October 26, 2013, in Schaffhausen. Meanwhile, an 80m prototype has been designed so that ham can use it for the National Mountain Day contest.

A dedicated introduction to the project including a soldering course began on March 1. There were two additional meetings on Saturdays March 8 and 22 in the Zeughaus (Uster) with theory discussions, tips and practical help in assembling the kit. The unit's developer, Peter Solf, gave a presentation about the MA-12 and provided details about the circuitry. Participants at the MA-12 meeting who were not able to complete their units, have additional needs or other assistance, can get in touch with me. The goal, as always, is to make every single unit fully functional. This offer is available until the end of 2014. hb9afh@htc.ch

The order of events was:  As a group: - Explain the circuits - Wind and measure the coils - Construction tips - Aligning the trx - As required: soldering course / soldering assistance - For every individual:  Kit construction - Time required:  two Saturdays (without soldering course) - Location: Altes Zeughaus, Uster. - Soldering course: Gossau ZH. Prerequisites: The desire to complete a project for which the HTC offered its support. Fact: Winding the coils was a key task, the appendix shows an example. In certain cases, to simplify matters, the next largest core size (T50) along with 0.3 mm copper wire was used. 20 people participated in the project. The project was organized and conducted by the USKA/HTC NMD Commission. The facilities were provided by the HAMFU IG/Uem. Last modification made on the MA-12, in respect to TX offset behavour, were made by Urs HB9ABO! Modifications and Dokumentation MA-12 you find in  Documentation. (login)

 EL-12 Instrument

EL-12 power, frequency, inductance and capacitance meter

This piece of test equipment was introduced as a group order for a HTC group project in preparation for the 2010 QRP Party. Each person constructed the kit at home. At the 2010 QRP Party in Rothenburg, each unit was calibrated at a professional lab test bench under the coordination of Ernst HB9CTP. A dozen members participated in the project.

Further details about the project were published in the HTC News Vol. 2 2009 and Vol 1 2010. We extend our grateful thanks to Roland HB9GAA, who designed this test unit, for making this wonderful project possible. The QRP Party was organized together with groups coming from HB9JA and the HTC.

ATS-3 project

ATS stands for Appalachian Trail Sprint. The Appalachian Trail is a hiking trail in the USA that extends for roughly 3500 km and goes through a number of states from Georgia to Maine. http://de.wikipedia.org/wiki/Appalachian_Trail

For many years, the rig's developer Steve Weber KD1JV hiked sections of this trail. In the winter months, he took his experience with earlier versions of his ATS units along with new thoughts and concepts to develop a next-generation unit. Steve made his radios available to other hams in the form of a kit, which he generally produced only in a series of roughly 100 units. These kits always sold out almost immediately.

In the HTC, three ATS group orders were organized. In total, 40 of these 5W SMD transceivers were built by HTC members. The units are named the ATS-3, ATS-3A and ATS-3B Each version has a slightly different circuit design.

Any reluctance people had towards soldering with SMDs during construction were overcome during a demonstration and practice during the HTC QRP Party in Rothenturm. Among HTC members are a number of "trailblazers" who have considerable experience with electronics and circuit construction, and they were available to assist whenever a problem arose.

Further kits from Steve KD1JV with similar circuit designs then followed. These are called the ATS 4, PFR-3 and the Mountain Topper.

Documentation: ATS 3   ATS 3A  ATS 3B