K7IYP TS-530 AM Modifications

Return to K7IYP Main Page

5301.JPG 964 KB	5302.JPG 885 KB	5303.JPG 979 KB
Well, here's the mess- er I mean, uh "rig". Haven't had any time to do anything else to it. The fixed bias supply will be moved from the Kenwood internal to a external divider to hopefully cure the intermittant grid- drive problem. Also, when I can locate it in my junk, I will insert a 25 ohm 25W pot in series w/the resistor across the xfmr input for more audio drive control. I want more output from the 12BY7A so I will work to increase the efficiency of that stage, maybe put an untuned amp stage ahead of it. When I'm sure it's stable I will install the W7CPA 6146W's and neutralize. Working on locating a Heathkit HP-13A to up the B+ to 750V. Then build the modulator and meters into a box.
5304.JPG 1020 KB	5305.JPG 724 KB	5307.JPG 962 KB
AM Filter generously donated by Bill, K7VZP, works great -- rig has a whole new personality.  Fidelity is superb.
5309.JPG 1130 KB	5310.JPG 990 KB	5311.JPG 1100 KB
Power supply components removed and cabling added for HP-10 and new metering and switching box.  Also a view of the bottom of the PA board showing replacement of the 4 20 ohm cathode resistors w/two 10 ohm 1W.  Plate and screen bypass caps have been replaced with .001uf to prevent modulation audio from being shunted to gnd.
5312.JPG 810 KB	5313.JPG 960 KB	5314.JPG 1040 KB
Front & rear views of rig, inside view of meter box shows mod xfmr., screen resistors & switches (PA B+ & Tune/Op to reduce screen voltage for tune-up).
5315.JPG 1110 KB	5316.JPG 700 KB	5317.JPG 830 KB
Station lt. to rt. -- TS-530S, Behringer 1202 FX mixer, Kenwood KAC-714 100W audio amp (under spkr), top volt and ammeters monitor batteries, bottom Heathkit 2140 A wattmeter, IC-2000 2m rig, IC-720A HF rig.  Mike is Shure SM-58.
5319.JPG 790 KB