JUMA Amateur Radio Forum

Days back when TRX2 DDS board was designed I was also experimenting with DSP radio concepts. My old experimental project can be found here http://www.kolumbus.fi/juha.niinikoski/Cheap_dsp/Cheap_dsp.htm I had plans to make codec option board and implement at least DSP filters maybe speech processor ...

Hello Callen
frequency dial is a Quadrature Encoder. For example DigiKey catalogue is full of them (several thousand types!). Bellow one suitable example.

PEC11R-4220K-S0024-ND
https://www.digikey.com/product-detail/ ... ND/6164059

73 Juha oh2nlt

Hello Frank if you have time please browse JUMA pages more deeply. Almost all pictures are hot links to larger detail pictures. There are also plenty of detail hot links embedded in the text. http://www.jumaradio.com/juma-trx2/ From the technical page http://www.jumaradio.com/juma-trx2/rev-b/index ...

Hello Geir
answer for your first question.

You can find original firmware binary from here.
http://www.jumaradio.com/juma-tx500/juma-tx500.hex

and full source code package from here.
http://www.jumaradio.com/juma-tx500/jum ... opers.html

73 Juha oh2nlt

Hello John SWR alarm means that the control board microcontroller measure some voltage in the REW-PWR analog input. Please see the schematic diagrams and start fault finding by measuring the voltage in the main board REV signal (J3 pin 2). Continue to the control board. Signal same is changed to REW ...

Hello Uwe yes BUFFER signal comes from micro controller I/O. If you follow the schematics you can find it at J3 / pin13. In the control board (same as PA100D control board) the signal name is changed to SPI_LATCH. Please check continuity with ohm meter. Also check that there are no short circuits to ...

PA100D auto band detect is base on input frequency counter. From the SSB signal it is sometimes difficult to decide right frequency range (band). If you have difficulties with auto band it is better to select the band manually and save the PA100D low pass filter switching relays. Switching filters ...

Hello Brett there is adjustable SCAF type filter in the TRX2. With push button you can quickly select one of the three setups. Each setup upper edge is adjustable. Following picture and the user manual explains the SSB/CW filter operation. http://www.jumaradio.com/juma-trx2/adjustable-filter.jpg ...

Hello Dave
J1 in the control board is for second serial port connection.
http://www.jumaradio.com/juma-pa100/pa1 ... cs-b-2.pdf

Second serial port (UART2) is not used in the standard PA100-D firmware. You should leave all J1 pins open.

73 Juha oh2nlt