DSI R-110B/LFE Receiver. Function of Plug-In Cards / Boards. Band1: 1khz - 250khz Band2: 250khz - 15Mhz A1 Microwave RF Module -Band 3 Processing and Conversion to IFs of 1450M, 550M and 21.4M -Input Limiter A2 Preselector Module -1.1GHz Input LPF for Band3 -523-533MHz Mixer Loop, Controls VCO in A1 Module for 550M to 21.4M Downconversion. A3 Wideband Filters 40, 100, 200MHz (Option) A5 Low Frequency RF Module -Band 1 & 2 Processing and Conversion to 21.4MHz IF. -300k and 15M Input Lowpass Filter, Limiter A6 21.4 MHz IF Amplifier Module -Filter Switching -Front End Overload Detector -Variable Attenuators -IF and Sig Mon Outputs. -AGC Input A7 21.4 MHz IF Filter Module with 6 Filters (For A6 Board) 50k,100k,200k,500k,1M,2M,5M,10M,15M LC and Xtal IF Filters. (Only "B" Version has A7 + different A8 Board with 9 Filters fitted? Normal Version has only 5 Filters on A8 Board Fitted.?) Not Mentioned in Technical Manuals. A8 21.4 MHz IF Filter Module with 3 Filters (For A6 Board) 50k,100k,200k,500k,1M,2M,5M,10M,15M LC and Xtal IF Filters, Part2 A9 Video Module (When A3 Option Board is fitted, a different A9 Board with Wideband Input has to be fitted too.) -wideband AM detection -narrowband AM post-processing (detection performed by DCIF) -wideband log detection and narrowband log-characteristic compression -BFO detection -video noise filtering -video output -Z axis output -audio signal source -DVM signal source -AGC signal source -back-end overload detection A10 Pulsestretch / Slideback (Option) A11 DCIF Module -Narrow bandwidth filtering from 200 Hz to 20 kHz -Programmable gain in the back end, for proper gain distribution -AM detection for narrow bandwidths -Back end overload status for narrow bandwidths A12 FM Demodulation (Option) A13 IF Filterbank for LFE 50 and 100Hz (Option) Not Mentioned in Technical Manuals. A15 Fixed LO Synthesizer Module -The low frequency RF input module (A1A5) requires a 3 MHz fixed LO to upconvert the low frequency input by that amount. -The DCIF module uses switched capacitor filters to determine the bandwidth, controlled by a timebase consisting of a PLL synthesizer on the fixed LO module A16 Low Frequency Synthesizer Module (DDS-Synth) A17 Microwave Synthesizer Module -100MHz OCXO -It contains the control sections for the two microwave synthesizers, the other parts of which are located in the microwave RF module (A1A1) and the preselector module (A1A2). It generates a 20 MHz reference for the low frequency synthesizer module (A1A16) About IF Filters A7 and A8: The Technical Manual talks about 5 IF Filters: 80k, 300k, 1M, 4M, 15M On Board A8 Our R110Bs have 2 Filter Cards: A7 has 100kHz Xtal Filter + 3 LC Filters (Maybe even 5) of Unknown BW. And also has A8 Card, with 50 & 200kHz Xtal Filters + 1 LC Filter of Unknown BW. (7 to 9 IF Filters) This would make sense: The DC-IF is able to deliver Filter Bandwiths from 200Hz to 20kHz. So: "Real" 50 and 100Hz Filters are on A13 LFE Board, then DC-IF Filters from 200Hz to 20kHz, on A11 Board + "Real" 50k,100k,200k,500k,1M,2M,5M,10M,15M Filters realized as LC and Xtal Filters on A7 and A8 Boards + "Real" 40M,100M,200M Filters on A3 Wideband Board. R-110 Datasheet Talks about 80 kHz, 300 kHz, 1 MHz, 4 MHz, 15 MHz Bandwidths. R-110B Datasheet talks about 50k,100k,200k,500k,1M,2M,5M,10M,15M Bandwidths. PLL Status LEDs: Some of the discrete lock status signals also drive indicator LEDs which show through the tops of their respective cardcage plug-in modules. An illuminated LED indicates out-of-lock, but make sure that the particular LED in question is associated with a loop currently in use, as some loops will be active but lose lock when they are not in use. "NS" Xtal Filters: P/N BPF Type Frequency 6dB bw 60dB bw S&L VSWR loss Power 99-20502 Gaussian 21.400MHz 50 kHz 200 kHz 50 Ω 1.5:1 <10dB <10 dBm 99-20503 “ “ “ “ “ 100 kHz 400 kHz “ “ “ “ “ “ 99-20504 “ “ “ “ “ 200 kHz 800 kHz “ “ “ “ “ “ 99-20516 Butterworth 455kHz 50 Hz 200 Hz “ N/A <20dB ≤3dBm 99-20517 “ “ “ “ 100 Hz 400 Hz “ N/A “ “ “ All above filters are 3 section, 6 pole xtal filters.