20210117 Wacom WP-641 SN 5280 Tune and Test
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Wacom WP-641 VHF Duplexer, S/N: 5280 *** January 17, 2021 / Tune and Test *** Low Pass Branch Services performed by www.DuplexerRepair.com (A service of Alabama Broadcast Services, LLC) www.DuplexerRepair.com Isolation: 85.15 dB Insertion Loss: 1.53 dB(*) *Note: Spec. is 1.5 dB or better Return Loss: 31.97 dB VSWR: 1.052:1 Match Efficiency: 99.936% 1:Mkr (MHz) dB 2:Mkr (MHz) dB 1: 147.06 -1.53 1> 147.06 -31.97 2> 147.76 -85.15 2: 147.76 -0.04 -90 -80 -70 -60 -50 -40 -30 -20 Abs dB Ch1 Ch2 1:Transmission /M Log Mag 10.0 dB/ Ref 0.00 dB 2:Reflection /M Log Mag 5.0 dB/ Ref -5.00 dB Start 146.760 MHz Stop 148.060 MHz Start 146.760 MHz Stop 148.060 MHz 1 2 Wacom WP-641 SN: 5280 LPB 2021-01-17 08:36:05 1 2 Ch1:Mkr2 147.760 MHz -85.15 dB 1 2 Ch2:Mkr1 147.060 MHz -31.97 dB
Transcript of 20210117 Wacom WP-641 SN 5280 Tune and Test
Wacom WP-641 VHF Duplexer, S/N: 5280*** January 17, 2021 / Tune and Test ***
Low Pass Branch
Services performed by www.DuplexerRepair.com(A service of Alabama Broadcast Services, LLC)
www.DuplexerRepair.com
Isolation: 85.15 dBInsertion Loss: 1.53 dB(*)
*Note: Spec. is 1.5 dB or better
Return Loss: 31.97 dBVSWR: 1.052:1Match Efficiency: 99.936%
1:Mkr (MHz) dB 2:Mkr (MHz) dB
1: 147.06 -1.53 1> 147.06 -31.97
2> 147.76 -85.15 2: 147.76 -0.04
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Abs
dB
Ch1
Ch2
1:Transmission /M Log Mag 10.0 dB/ Ref 0.00 dB
2:Reflection /M Log Mag 5.0 dB/ Ref -5.00 dB
Start 146.760 MHz Stop 148.060 MHzStart 146.760 MHz Stop 148.060 MHz
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2Wacom WP-641 SN: 5280 LPB
2021-01-17 08:36:051
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Ch1:Mkr2 147.760 MHz
-85.15 dB
1
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Ch2:Mkr1 147.060 MHz
-31.97 dB
Wacom WP-641 VHF Duplexer, S/N: 5280*** January 17, 2021 / Tune and Test ***
High Pass Branch
Services performed by www.DuplexerRepair.com(A service of Alabama Broadcast Services, LLC)
www.DuplexerRepair.com
Isolation: 90.18 dBInsertion Loss: 1.91 dB(*)
*Note: Spec. is 1.5 dB or better
Return Loss: 38.10 dBVSWR: 1.025:1Match Efficiency: 99.985%
1:Mkr (MHz) dB 2:Mkr (MHz) dB
1> 147.06 -90.88 1: 147.06 -0.03
2: 147.76 -1.91 2> 147.76 -38.10
-90
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Abs
dB
Ch1
Ch2
1:Transmission /M Log Mag 10.0 dB/ Ref 0.00 dB
2:Reflection /M Log Mag 5.0 dB/ Ref -5.00 dB
Start 146.760 MHz Stop 148.060 MHzStart 146.760 MHz Stop 148.060 MHz
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2Wacom WP-641 SN: 5280 HPB
2021-01-17 08:39:50
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Ch1:Mkr1 147.060 MHz
-90.88 dB1
2
Ch2:Mkr2 147.760 MHz
-38.10 dB
Wacom WP-641 VHF Duplexer, S/N: 5280*** January 17, 2021 / Tune and Test ***
Service/Reference Photos
Services performed by www.DuplexerRepair.com(A service of Alabama Broadcast Services, LLC)
www.DuplexerRepair.com
Wacom WP-641 VHF Duplexer, S/N: 5280*** January 17, 2021 / Tune and Test ***
Service Notes & Comments
Services performed by www.DuplexerRepair.com(A service of Alabama Broadcast Services, LLC)
www.DuplexerRepair.com
There is notable oxidation of the locking nuts, hardware, and on the Invar tuning rods, which is most likely due to age and ambient moisture. Most – if not all – of the PL-259 and SO-239 connectors are similarly showing notable oxidation. There would most likely be similar oxidation found in the loop assemblies, tuning cylinders, and tuning pistons. This is most likely the major cause of the insertion loss (IL) in each branch being higher than the original factory specification of 1.5 dB or better. Given the significant labor which would be required – along with at least $200-245 in high quality connectors and cable which would be required to rebuild the harness – an overhaul of this set is not recommended since this model duplexer only has a specified isolation of 85 dB at the lower channel spacing specification of 500 KHz. Instead, investing in a duplexer assembly with at least 100 dB isolation specification (either new, or used but in better physical condition) would be recommended in this instance. Also, investing in a 6-cavity duplexer assembly which uses precision trimmer capacitors instead of Rexolite stubs/rods for purposes of notch/reject tuning would contribute to better notching/isolation (i.e., decreased desense and noise issues.) For use in a very high ambient RF environment such as the location where this set is being used, this duplexer assembly is somewhat lacking in specifications and performance.
