Re: [TenTec] Orion AM RX Performance Measurements

[Sinisa Hristov <shristov@ptt.yu>]

Grant Youngman wrote:

> Take a look at what happens to THD at a passband shift of 2000 Hz or over



Part Four - THD & IM with PBT offset
====================================

Sub RX, V2.056, 900 kHz, AM
BW 6000 Hz, PBT = 2000 Hz
HANG 0.3 seconds, 5 dB/s
measured at speaker output with external 4 Ohm speaker connected


Total Harmonic Distortion

modulation frequency = 1100 Hz


mod. depth   THD
------------------
   10 %      7.5 %
   20 %      4.7 %
   30 %      4.9 %
   40 %      6.0 %
   50 %      7.2 %
   60 %      8.6 %
   70 %     10.1 %
   80 %     11.5 %
   90 %     13.0 %
  100 %     14.5 %


Intermodulation

modulation frequencies 1400 and 1500 Hz
peak modulation depth 80 %

The level of 100 Hz intermodulation product
is -18.8 dB below single tone, i.e. 11.5 %.


73,

Sinisa  YT1NT, VE3EA