Method pre-settings of input bandpass filters

The essence of the method consists in the following: amplitude-modulated signal from the GSS using a custom bandpass filter (PF) is supplied to the amplitude detector and with him - on USC. Thus, it is possible with sufficient to Amateur radio practice accuracy is quite visually assess hearing on parameters such as bandwidth and shape factor of KP. KP is convenient to define at the level of - 6dB, where Um/Uвых=0,5.

If necessary, using the elements included in PF, these settings can be adjusted.

For more precise adjustment use the standard technique of removing the AFR, however, as practice has shown, the implementation of this time-consuming and laborious work after setting the above method as a rule is not required.

By using this technique, you can assess EMF, quartz filters with unknown parameters, which may be at the disposal of Amateurs. Well heard all the "humps" and "hollows" of the AFR.

Author: N. Nefedov, Kazakhstan, Aktobe region, the town of Emba; Publication: N. Bolshakov, rf.atnn.ru