Author Topic: LPAM MF Top Band Transmitter  (Read 102 times)


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LPAM MF Top Band Transmitter
« on: December 18, 2021, 10:05:21 am »
Here's one of my later Lock Down Projects, a MF Top Band AM Transmitter with 1W PEP. I must state that I did not develop the board that's inside the TX, this was purchased from a seller I found on eBay. I spent some weeks putting it under test before I decided it deserved to be boxed.

Not much technical data was given with the transmitter, apart from it's frequency generation method (DDS) and the output power. It lacked any circuit description and the method of modulation, but I would guess it's just the DDS module feeding a series mod buffer into the final PA stage. No output filtering is included, but checking for harmonics, I found they are very very low, about -60dBm from the fundermental.


Below showing a photo of the project box I decided to use. This wasn't all that expensive and gives a very nice semi-professional look.


The project box was first fitted with a ground chassis plate to mount the TX PCB too. Luckily the way the project box was designed allowed for this to be easily implemented. Then came the next job of cutting out the holes for the three sockects on the rear back panel.


I decided on N Type socket for the RF output, a 2Pin Aviation plug for the power, and XLR for the audio as used on professional broadcast equipment. At this point being photographed the front panel has yet to be populated with the LCD, Rotary Encoder, Key Lock, Fuse holder and Power Switch. The PCB only included the LCD and Rotary encoder, the other items I added for either extra functions / sercurity and protection.


« Last Edit: January 20, 2022, 10:19:13 pm by ZXBasic »

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