We want to buy either a uBitx, multiple band or bitx40, single band, for "experimental use", apart from normal use.?
We have a Arduino DDS AD9850 board programmed to generate psk31 RF at hf freq. It transmits about 1 mili watt, 0 dBm, to a dummy load ok.
We plan to cut pin 1 of T2, top left corner of circuit diagram of ubitx, at below link, to isolate the rest of the circuit. The dds signal will go into TP1. Appropiate relay will be energized. Singal from dds has been cheched and was clean enough, as it has its own filter also added, the ubitx has filter L1 to L4.?
Before we buy it, would appreciate advises from the forum.? Will the same mod work on the single band bitx40? I was told the diode mixer "generally" work at -16dBm. Will that be the case for these 2 radios?? It will be simple to use resistor attenuator, if dds output is too strong. If it is too weak, we are not too confident to add an amplifier ourself. Any advises on this will be appreciated
Singal into the 2 stages PA will be clean enough. Likely cleaner than the ubix as the diode mixer generate some unwanted signal. Any idea on the output spectrum purity (pa and post pa lpf)
73 Simon
