Test Report for IC-7851 July 1 and September 21 …

1 1 Test Report for IC-7851 July 1 and September 21-22, 2015; June 10, 2016 by Adam farson va7oj / ab4oj (Iss. 3) The following are the results obtained from lab tests which the author conducted on Icom IC-7851 S/N 02001019, kindly loaned by Allan Buckshon VE7SZ. The installed firmware versions were for the receiver tests and for the transmitter tests. The baseline configuration for all receiver tests was MAIN Receiver, NR/NB/ATT/Notch off, AGC Slow. Note: NPR with kHz roofing filter was measured on IC-7851 S/N 02001089, kindly loaned by Icom Canada. A.

2 Receiver Tests (July 1, 2015): 1. MDS (Minimum Discernible Signal). Test setup: Marconi 2018A signal generator, 20 dB pad, DUT ANT1 input. HP 339A distortion meter at EXT SP jack as level meter. 2. NPR (Noise Power Ratio). Test setup: Wandel & Goltermann RS-50 and RS-25 noise generators (fitted with filters per Table 2), 75/50 RF transformer, DUT ANT1 input. DUT set to LSB for all test frequencies except 5340 kHz (USB). kHz IF filter selected. Noise loading adjusted for 3 dB increase in audio output at EXT SP jack, as read on HP 339A. NPR derived by calculation.

3 3. RMDR (Reciprocal Mixing Dynamic Range). Test setup: Marconi 2018A signal generator, 3 dB pad, 9830 kHz bandstop filter, 0-110 dB step attenuator, DUT ANT1 port. HP 339A distortion meter at EXT SP jack as level meter. 4. DR3 (2-Tone 3rd-Order IMD Dynamic Range). Test setup: Marconi 2018A and 2019 signal generators, MCL ZHL-32A buffer amplifiers, MCL low-pass filters appropriate for band tested, 20 dB pads, MCL ZSC-2-1W combiner, 0-110 dB step attenuator, DUT ANT1 input. Test signal level adjusted for 3 dB increase in audio output at EXT SP jack, as read on HP 339A.

4 5. Roofing-filter bandwidth: As for 1. 6. Spectrum scope RBW: As for 1. 1. MDS (Minimum Discernible Signal) tested on MHz in CW mode (500 Hz), Preamp off, 1 and 2 in turn. Roofing filter: 15, 6, 3 and kHz in turn. The MAIN receiver is tuned to f0 = MHz and a test signal applied. For each preamp/roofing filter combination, the input power Pi required to raise audio output noise level by 3 dB is noted. Pi = MDS. NR/NB/ATT/Notch off, AGC Slow for all tests. Refer to Table 1. A variant of MDS is also measured in SSB mode ( kHz) at each of the four NPR test frequencies in turn, for use in calculating NPR.

5 The measured MDS values and roofing-filter correction values are given in Table 2. Table 1: Minimum Discernible Signal (MDS). MHz, 500 Hz CW Roof Flt kHz 15 6 3 Preamp Off -126 -125 -125 -117 1 -138 -137 -137 -129 2 -142 -141 -141 -136 2. NPR (Noise Power Ratio), tested in SSB mode ( kHz) with Preamp off, 1 and 2 and with 15, 6 and 3 kHz roofing filters, and in CW mode (500 Hz) with kHz roofing filter. MAIN Receiver A tuned to notch centre. Noise loading PTOT adjusted for 3 dB increase in audio output. kHz roofing filter calibrated prior to test.

6 NPR calculated per Appendix 1. See Table 2. 2 Table 2: NPR test data (1940, 3886, 5340, 7600 kHz). DUT BSF kHz BLF kHz Config MDS dBm PT OT dBm BWR dB NPR dB IC -7851 19401 Preamp off R15 -122 88 R6 88 R3 89 -120 36 84 Preamp 1 R15 -134 -14 91 R6 90 R3 89 -133 36 84 Preamp 2 R15 -136 86 R6 -21 86 R3 86 -139 36 83 Digi-Sel R15 -125 91 R6 90 R3 90 -123 36 87 38862 Preamp off R15 -123 86 R6 84 R3 83 -121 + 83 Preamp 1 R15 -135 89 R6 87 R3 87 -133 83 Preamp 2 R15 -137 85 R6 83 R3 84 -139 -19 83 Digi-Sel R15 -122 84 R6 82 R3 82 -123 + 84 53402 Preamp off R15

7 -123 85 R6 85 R3 85 -121 + 82 Preamp 1 R15 -135 88 R6 88 R3 87 -133 82 Preamp 2 R15 -137 83 R6 84 R3 84 -139 82 Digi-Sel R15 -122 84 R6 82 R3 83 -122 + 83 BSF: Bandstop (Notch) Filter. BLF: Band Limiting (Bandpass) Filter. 3 Table 2a: NPR test data (7600, 11700 kHz). DUT BSF kHz BLF kHz Config MDS dBm PT OT dBm BWR dB NPR dB IC -7851 76003 Preamp off R15 -123 85 R6 85 R3 85 -121 + 42 81 Preamp 1 R15 -134 88 R6 88 R3 87 -133 42 82 Preamp 2 R15 -137 83 R6 84 R3 84 -133 42 81 Digi-Sel R15 -123 85 R6 84 R3 85 -124 0 42 82 117001 Preamp off R15 -122 -1 83 R6 + 83 R3 + 83 -120 + 76 Preamp 1 R15 -134 -9 87 R6 86 R3 86 -134 81 Preamp 2 R15 -137 82 R6 82 R3 81 -139 78 Digi-Sel R15 -120 + 83 R6 + 83 R3 + 82 -120 78 BSF.

8 Bandstop (Notch) Filter. BLF: Band Limiting (Bandpass) Filter. Notes on NPR test: 1. MDS shown for R15. Correction factors: R6: +1 dB. R3: +2 dB. 2. MDS shown for R15. Correction factors: R6: +2 dB. R3: +2 dB. 3. MDS shown for R15. Correction factors: R6: +1 dB. R3: +1 dB. 4. MDS stated separately for (measured on different DUT). 4 3. RMDR (Reciprocal Mixing Dynamic Range). Test Procedure: Signal generator frequency (f0) tuned for max. null in audio output measured at EXT SP jack; DUT tuned to f0 = kHz. Signal generator then tuned to f0 f and output Pi increased to raise audio output by 3 dB.

9 Test Conditions: DUT in CW mode, B = 500 Hz. kHz roofing filter selected. Preamp off. Measured MDS = -119 dBm. RMDR = Pi MDS. Phase noise = -(27 + RMDR) dBc/Hz. See Table 3. Note: The residual phase noise of the measuring system is the limiting factor in measurement accuracy. Table 3: Reciprocal Mixing Dynamic Range (RMDR) at 9830 kHz. f kHz Pi dBm RMDR dB Phase noise dBc/Hz 1 -5 114 -141 2 -2 117 -144 3 -2 117 -144 5 -2 117 -144 10 -1 118 -145 20 +6 125 -152 MDS = -119 dBm 4. DR3 (Two-Tone 3rd-Order IMD Dynamic Range) tested in CW mode (B = 500 Hz), Preamp off, and 3 kHz roofing filters.

10 Test frequencies 14100/14101, 14100/14102 and 14100/14120 kHz. The receiver is tuned to the lower and upper IMD products in turn; the test signal level Pi is adjusted for a 3 dB increase in audio output at the EXT SP jack. DR3 = Pi MDS. DR3 is measured with the and 3 kHz roofing filters in turn. The results are given in Table 4. At 20 kHz spacing, DR3 is 3 dB worse with the kHz roofing filter than with the 3 kHz filter. This is due to passive IMD (PIM) in the kHz roofing filter at the high test signal levels used. Table 4: DR3 Test Data. Roof kHz Spacing kHz f1 kHz f2 kHz Lower IMP kHz Upper IMP kHz Pi dBm MDS dBm DR3 dB 1 14100 14101 14099 14102 -30 -117 87 2 14102 14098 14104 -20 97 20 14120 14080 14140 -13 104 3 1 14100 14101 14099 14102 -37 -125 88 2 14102 14098 14104 -30 95 20 14120 14080 14140 -18 107 5.