Hallicrafters SX-88 RUN 3
wa2pjp:
I thought I might share the story about the SX-88 I acquired last year from the second owner as a project. It was S/N 294 Run 2 and was pretty dirty, neglected, rotted line cord, just what you would expect from a piece of gear sitting in a basement for 30 years. The pictures below show the radio as I got it before I had done any work to it. The receive sat in the owner's basement on a shelf for about 30 years because it had failed and no one was able to repair. The owner said he had given it to several different techs to trouble shoot the problem, but no one was able to find the problem and repair it, so since I was looking for an 88 again, I thought I would take a chance and purchase it. Looking at the bottom of the chassis, there were several of the molded paper caps cut out (bumble bee caps), wires unsoldered and loose hardware, I guess from techs that thought that's the way to trouble shoot a problem........ The first pictures show the front panel and who ever removed and replace the panel (one of the techs that worked on it), wired the switches wrong and his fix was to put tape over the panel markings and write on it rather than wire the switch correctly..... the last picture is of course with the panel removed and you can see the condition of the chassis. I have owned several 88's in the past and just moved them on because I was never impressed with their performance.
wa2pjp:
The next pictures show the dismantling of the chassis and the second IF chassis that was mounted to the top of the main chassis.....anyone who is familiar with the 88 knows that the second IF chassis is very difficult to remove since all the wiring runs down through the main chassis and is wired to various parts of the radio. The problem that plagued this radio was a burned open resistor under the second IF chassis that was bypassed with a molded paper cap (bumble bee cap) that had very high leakage current to ground. Since none of the techs that worked on this radio was willing to remove that chassis, the poor guy who owned this radio never got very much use of it. The first two pictures show the bottom of the second IF chassis and the last pictures is after I had finished replacing all the parts and wiring. I checked the two crystal frequencies and found that both crystals were way off freq. so I order two new ones to replace the old ones. Bench checking the oscillator showed to be only a few cycles off spec.
wa2pjp:
After stripping all the parts off the main chassis I had sent it out along with brackets, gussets and shafts to be replated at the chrome plating shop. The first pics are of the chassis after all the tube sockets and terminal strips were removed Also, the last picture is of the harness before I removed wires that were cut too short and force to fit or reach a tube socket or terminal strip. One of the leads in the harness was cut so short that the terminal strip it was connected to was bent way over just to make the connection.....JUST POOR craftsmanship.
wa2pjp:
Here is the chassis back from the plating shop in the first picture and the underside after I installed all new tube sockets and terminal strips. On the tops sidethe IF cans remounted. Most of the tube sockets just had poor pin tension and the terminal strips were just over heated and I found on one of the strip, large solder blobs had dripped down though the eyelets and came with in mils of shorting to the chassis.....again just poor craftsmanship and I guess the QC department was on break.
wa2pjp:
Here is the underside of the chassis with the harness reinstalled and most of the chassis components installed. I replace every resistor and cap with new ones and replaced the wiring in the harness that was cut short at the factory. The third and second pictures is of the RF sections and band switch which I completely dismantled to get to components that were located under the switch such as the molded papers and burned resistors and to also clean the switch contacts properly.