Portsdown Output Levels
The typical performance for a well-adjusted Portsdown Filter-modulator board, being driven by a black ADF4351 module through a VCO Filter is as follows:
| Frequency MHz | SR | Output Level dBm | MER dB from MiniTioune V0.5a |
|---|---|---|---|
| 71 | 333 | 9.6 | 25 |
| 146.5 | 333 | 10.1 | 26 |
| 437 | 333 | 9.2 | 26 |
| 437 | 1000 | 9.0 | 26 |
| 1255 | 333 | 5.0 | 26 |
| 1255 | 1000 | 5.0 | 26 |
| 2400 | 333 | −7.0 | 25 |
| 2400 | 1000 | −7.0 | 25 |
These figures were measured by G8GKQ using a Version 1 board (as sold by the BATC Shop in Jan/Feb 2017) modified to Version 1a standard. The measured performance of the the factory-assembled V1a boards was very similar. Figures are included for 2.4 GHz out of interest - this is well outside the specification for the board.
Spectrum plots of version 1a
1255MHz, 333ks, 5MHz/division
1255MHz, 333ks, 500KHz/division
1255MHz, 1Ms, 5MHz/division
1255MHz, 2Ms, 5MHz/division
1255MHz, 4Ms, 5MHz/division