Electronics and Technical resources from vu3dxr
SSM2167 Microphone Preamplifier with compression for ubitx HF Transceiver This DIY project idea based on the small board module “SSM2167 Microphone Preamplifier Board Preamp Compression Module DC 3V-5V” widely available on eBay and Aliexpress. Mic gain is barely adequate on the µBITx transceiver since there is no Mic Gain control. It would also be helpful …
Modified simple horizontal V antenna This antenna is little modified version of antenna designed by Adam 9A4QV for noaa/METEOR Weather sat reception. Adams antenna is based on a very simple linearly polarized dipole, which makes construction almost trivial. I tried his antenna and found that practical difficulties in finding choc block terminals. Chock block terminals are not strong enough …
This programming cable is intended to be used with the computer usb port for motorola GM360 radio. To program the Motorola GM360 using a ribless cable, you can use a cable that connects straight to the computer without needing any special box. One type of ribless cable is the RS232 to port RJ45 (front microphone …
The GM300 series radios are line of two-way radios manufactured by Motorola Solutions. They are popular choice for amateur radio operators due to its features, performance, and affordability. GM300 is also a very durable radio. It is built to withstand the elements and can handle even the most demanding conditions. Similarly, the Motorola GM338 is …
DIY Programming cable for a Motorola GM 300 series two-way radio To make a DIY programming cable for a Motorola GM300, you will need the following materials: A USB-TTL adapter An RJ45 Ethernet connector A standard silicon signal diode, such as the 1N4148 An Ethernet cable. Once you have gathered your materials, follow these steps …
VK3YE’s AGC circuit for ubitx An ubitx AGC board is a circuit board that can be installed in a ubitx transceiver to provide automatic gain control (AGC). AGC is a feature that automatically adjusts the gain of the transceiver’s amplifier to maintain a constant audio output level, regardless of the strength of …
1:49 UNUN using two stacked FT240-43 cores for end fed halfwave antenna In order to match the end fed half wave antenna to the coaxial feeder, it is necessary to have a matching network or transmission line transformer. The coaxial feeder is likely to be 50Ω and the antenna impedance is possibly around 4000 or …
Ten Minute QRP Transmitter The design apparently originated in 1996 in an amateur radio club QRP publication. The name originates since the original author claimed he built this transmitter and make a QSO with it in just 10 minutes time. There are no coils to wind it tunes a wide range of crystal frequencies, and it outputs an …
Adaptation of Class E amplifier for amateur radio application is very rare due to inherent difficulties in filter design associated with it till release of usdx transceivers. The above compact transmitter uses class E amplification with three BS170 mosfets, a popular approach in usdx final. What’s new is the oscillator…any similarity with the NS40 is …
Half Rhombic antenna with counterpoise was published in RSGB Radio Communication magazine December 1996 page 62. Refer for more info about broadband terminated end fed antenna here.