I am continuing with the repairs on my TR7, and since I have the rig open, I pulled the PA module and did an analysis similar to the one performed by K8AC that is posted on the website at:
http://www.wb4hfn.com/DRAKE/DrakeArticles/TR7_Amp_Repair/TR7-Amp.htm Using an HP 8640B signal generator, I recorded the drive voltage needed to produce 100W output on a Bird Wattmeter. The module current values are approximate, and the efficiency (also approximate) was calculated as (RF Power out / (Module Current * 13.8V)) * 100 The results are shown below -- from what I am seeing, the PA looks to be in OK shape as is. Since I am not getting any RF output from the rig, I will continue working from the front of the TX chain. f (MHz) Drive (mV) P out (W) I module (A) Eff % 1.865 32 100 22 32.9 3.580 36 100 22 32.9 3.950 40 100 21 34.5 5.372 54 100 21 34.5 7.005 70 100 20 36.2 10.050 95 100 20 36.2 14.025 120 100 20 36.2 18.130 130 100 18.5 39.2 21.300 118 100 19.5 37.2 24.920 110 100 18 40.3 28.300 140 100 16 45.3 28.800 140 100 16 45.3 Charles K5QED
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