Drake MSR-2 Shortwave Receiver

Serial Number: 355 (EAC/Radiomarine R7)

Year of Manufacture: 1973 (7331 latest observed IC date code)

Date of Receipt: 2016 Feb (for examination & repair only)

Source: GO

State upon Receipt: Several knobs have been replaced with non-original types. Functional but some erratic behaviour. The wire-pin connectors on the PCBs - which were intended to allow disconnection of the wires for board removal - have been soldered over. These connectors were cheap and unreliable.

Date:	2016 Feb
Symptoms:	Sensitivity / reception is erratic with turning of tuning switches.
Examination:	Tracked to broken solder joint between pin and PCB around antenna input on rear-most board.
Procedure:	Resoldered.

Date:	2016 Feb
Symptoms:	Reception still erratic with jiggling around 4th board from rear.
Examination:	Poor soldering of wire-pin (white-blue wire) on 4rd board from rear.
Procedure:	Resoldered.

Date:	2016 Feb
Symptoms:	When tuning into the upper overlap region (above the top of the 100KHz VFO span) when the hundreds-KHz knob is at '9' - that is, when a carry into the MHz digits is necessary - 6 is added to the MHz display rather than 1. E.g. the display transitions from 01,999.9 to 07,000.0 rather than 02,000.0 .
Examination:	Somehow the 'carry' wafer (3rd from front) of the hundreds-KHz switch had been installed rotated 180 degrees.
Procedure:	Knob and shaft slid out so wafer could be rotated to correct position, knob and shaft reinserted.

Date:	2016 Feb
Symptoms:	Erratic display in the hundreds-Hz and units-KHz digits, observable with jiggling of the counter board.
Examination:	Solder joints at edge connector on display board appear to be fractured. Edge connector not seated fully.
Procedure:	Edge connector removed, reseated and resoldered. Also, new solder posts for two wire connections on display board created, due to lifting PCB trace.

Date:	2016 Feb
Symptoms:	Units-KHz digit oscillates between odd/even, affected slightly by pushing on counter board.
Examination:	Bad solder joint to U1703.13, 1 & 8 bits don't get latched. Top-side trace is soldered directly to pin due to lack of plated-through holes. Solder was balled and not flowed properly.
Procedure:	Resoldered.

Date:	2016 Feb
Symptoms:	Hundreds-Hz digit still erratic, notably going from 0 to 8, again affected by pushing on counter board.
Examination:	8-bit going high when it shouldn't at U1802 (74141) but stable back at U1702 (7475).
Procedure:	1 & 8 bit lines resoldered on display board at edge connector and U1802.

Serial Number:	355 (EAC/Radiomarine R7)
Year of Manufacture:	1973 (7331 latest observed IC date code)
Date of Receipt:	2016 Feb (for examination & repair only)
Source:	GO
State upon Receipt:	Several knobs have been replaced with non-original types. Functional but some erratic behaviour. The wire-pin connectors on the PCBs - which were intended to allow disconnection of the wires for board removal - have been soldered over. These connectors were cheap and unreliable.