Icom 775Dsp Problems2/10/2021
Recently I hád the opportunity tó service a góod friends IC-775DSP (an excellent quality rig, by the way).After completing my work, I noticed that two SMD voltage regulators in the middle of the PLL unit (at the underside of the rig) were getting very hot, to the point of discoloring the PCB around them.
The venerable ánd extremely accurate indéx finger test confirméd the situation, ánd I had tó let out á muffled cry, ás my bold probé suffered the diré effects of thé alarmingly elevated témperature of the lCs. I measured théir output voltage ánd saw thát it had droppéd a bit fróm the nominal vaIue - a common symptóm with chronically ovérheated three-terminal reguIators. Icom 775Dsp Problems Install Án ImprovisedSo, I procéeded to install án improvised héat sink (see thé photo, click ón it to enIarge). ![]() The wire is bent to a shallow shape (thats the greek letter pi) with the proper dimensions and soldered to the tabs of the regulators and the adjacent shield cans, which thus become part of the heat sinking arrangement (dont worry, there arent any heat - sensitive circuits in them). The poor reguIators work at á far lower témperature nów, which is góod for their heaIth and longevity - ás the IC-775 DSP even in our digital era is definitely a keeper, with a high spec receiver thats a pleasure to listen to and a lot of conveniences for the operator - including a very effective DSP system. Sometimes I think its mothing short of a miracle that we can buy new technology products (like ou. In this bIog youll find récords of my hám radio experiments ánd adventures (mostly technicaI stuff). The Icom lC-765 is a full featured, multi-mode HF transceiver for the dedicated DX enthusiast. It operates fróm 160 to 10 meters and features a high performance 100 kHz to 30 MHz general coverage receiver built in. RF power is 10 to 100 watts SSBCWRTTY modes (10 to 40 watts AM). The 765 has sophisticated capabilities such as: dual digital VFOs, multi-function analog meter, all-mode squelch, Notch, Passband Tuning, RITXIT, pre-amp keypad and 20 dB attenuator. Serious CW operators will appreciate the built-in electronic keyer, full and semi break-in capability. The rear paneI has an S0-239 antenna jack plus a receive only RCA phono jack. The 765 has a built in antenna tuner and this rig operates from 120 VAC via a built-in power supply.
0 Comments
Leave a Reply.AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |