ALIGNMENT w/ SWEEP of Rebuilt IF Cans - GE AM Tube Radio Repair from 1957- Part 4 - GE Model 875 4K скачать в хорошем качестве

ALIGNMENT w/ SWEEP of Rebuilt IF Cans - GE AM Tube Radio Repair from 1957- Part 4 - GE Model 875 4K

After fixing the IF transformers in this 1957 General Electric tube radio, we need to re-align the radio IF transformers because we changed the capacitors in the previous episode. I do this with a sweep generator (AKA HP3336B) to get the alignment close, then finish peaking with a modulated single frequency. Due to the change of the IF capacitors, especially with non-exact value substitutions, we find that sweeping the IF frequency helps to get the IF transformers into range so that we can align by signal generator set at the IF frequency. Before doing so, the alignment results were just not good enough. Then we will need to work on the power system and case in the next episode. We are working on this 65 year old General Electric tube radio, model 875, from the mid-century. See the checklist which appears, when status changes, for tracking what is discovered that needs addressing in Red, followed by Green when resolved. This is a good example of an All-American Five radio. This is a multipart series made primarily to show the person who will end up with this radio how it works and what was involved in getting it repaired. (However, the repair required for this radio has advanced to a level I had not anticipated, so while I meant it to be high level at the beginning, it really got into the weeds.) This person may have limited exposure to some of these topics so there is some time spent on background and some safety info for their benefit. Experienced hands please be patient. Constructive words of wisdom in the comments are always welcome. This is not instruction, it is for entertainment. If you attempt to do some of the things in this video you at your own risk. Check out some of the power supply safety issues mentioned in Part 1, and especially the link below to Mr Carlson's Lab video. Some vintage equipment used along the way: EICO 625 Tube Tester, circa 1958 HP 3336B Synthesizer/Level Generator (with Sweep), circa 1979 B&K Precision 1541 40MHz Dual Trace Analog Oscilloscope, ca 1985 Acknowledgments and References: Thanks to Ray at Radio Workshop for great material and for the idea for the magic of showing earlier video clips. Happy days indeed!    / g4nsj   Frequency generator modification to add an inexpensive frequency counter: Thanks Tony B. for the video and description - it works very well! Here is the link to the xraytonyb video (he also demos it by doing an alignment):    • Tenma Signal Generator Mod and Demo   Awesome discussion of bench safety including variacs and isolation transformers by Mr Carlson's Lab (highly recommended):    • Tech Tips Tuesday, Isolation Transformer a...   Modification method for a commercial Tripp Lite isolation transformer for tech-bench use by Todd Harrison, his channel is called ToddFun:    • ToddFun.com: Isolation Transformer - Tripp...   Schematic: Sams Pub. Set 376, Folder 11, November 1957 Modern Frequency/Signal Generator: Lodestar SG-4160B Camera: Canon G7X Mark III Mic: Rode Micro Video Editing Software: Power Director Jump to: 0:01Intro / Review 1:41 Part 4 / Flight of the Bumblebee 6:48 Alignment Set Up 11:23 A Visit from the Future 12:47 IF Alignment Take 1 14:27 Osc, Ant Alignment 22:37 Back to the Future/Present 23:48 Sweep Set Up 32:48 Align by Sweep 37:07 Finish Up w/ Single Freq 43:32 Review of Steps Taken 44:06 Revisit a Mystery 45:46 Plans for Part 5