km6oyh
| Joined: | Sun, Dec 10th 2017, 23:35 | Roles: | N/A | Moderates: | N/A |
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| Topic | Created | Posts | Views | Last Activity |
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| Intro & TS-440S/AT & TS-440SAT Restorations | Feb 15th 2018, 05:36 | 2 | 10,086 | on 30/10/19 |
Latest Posts
| Topic | Author | Posted On |
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| Intro & TS-440S/AT & TS-440SAT Restorations | km6oyh | on 15/2/18 |
| Howdy All, Ok..I'm newbie. I studied for the novice class when I was around 13yro, but things in the homeworld, mom was being visited by greys, but no one understood what was happening, things became weird at home, and it interfered with my code studies, I was distracted. 50 years later, I passed the Technician class test in December and next weekend I'm taking the General class test. I am back to studying dit dah dit dah, it calls to me. As for repeaters I can see the utility, but to exclusively use them? Might as well use a cell-phone, what's the adventure in that? So, I got my ticket. While I do have a lab, its mainly comprised of logic-analyzers, cpu emulators, function generators, development systems, soldering irons and one really big, old, sweet, 100Hz to 1.7GHz HP spectrum analyzer. Two peices, 100Lbs. I had never actually seen such a unit until I was hired by major defense contractor to debug a rackmount prototype control-segment GPS measurement receiver. One small area of the receiver HW was actually a 'radio', all the remaining stuff was computers, wires, oscillators, digital correllators, POL power supplies. So I got my footsies wet in microwaves and miniature SMA, SMC plumbing. It was fascinating work. We had in the lab two $300k space-vehicle constellation simulators and whole bunch of spectrum analyzers. I grew to really appreciate those magnificant HP tools. Now what did those managers rename that company? Keysight, hah hah. H & P would be turning over in their graves if they knew. So here I was, back in December with ham ticket in hand and not one peice of ham gear in the place. So I started looking around for a rig. The 2m stuff just doesn't call to me. My yard isn't big enough for a long wire 160m or even 80m, but 40 upto 6m is promising. So I started looking around on eBay for a rig. Prices have gone out of sight since the 60s when I was studying for my novice. Then I saw an old Kenwood TS-530, with tubes! Sightwise it was a big base rig to behold and was only a coupld hundred bucks!! 160m upto 6m, perfect. And there's just something about a final being comprised of a couple of power tubes...just feels right to me. The transistor-sister newbies wouldn't understand that. So I contacted the eBay seller, asked a few questions, and in the course of 15 minutes, the seller had cancelled the sale, without any explanation. I wrote'm, no response. Cheesy, very cheesy. So, I was back to looking for another rig, and bumped into a Kenwood TS-440S, all solidstate. I guess I can live with that? But in any case, there was just something about it that called to me, and is the only way I can describe it. Only this time, I read up on it, I checked out the reviews on eHam, and what hams were saying about their TS-440S. Lots of hams love those rigs. The more I read, the more I had to have that transciever!! So, I bought one. It was advertised as being broken but for a really decent price. It came from Florida!! They had recently been inland swimming. And sure enough, one side of the radio appeared to have corrosion damage. It was as though it had lain on one side in about 1 inch of some mildly corrosive liquid. Only a few front panel components were affected, the power switch being one, and the metal skeleton. So I had a radio with no power-cord or power supply. 1st thing acquired was an original Kenwood, used, printed service manual and schematics. Spec's showed 13.2Vdc @25Amps when keydown. So back to eBay where I picked up a nice Astron linear supply. But I had no coax, no dummy loads, no power meter, no antenna and no microphone or key. Via eBay, now I got everything except an antenna, LMR400 coax and a power meter. I'll get'm when I need'm. So I hooked up the MFJ 300W dummy load, and plugged in the power-cable/connector from the Astron PS. Turned it on and nothing. No meter light, no readout on the flourescent Fr display, no sound emitting from the speakers, nothing, no buzzing, zip. My first thought, 'aw poop, the power-supply must be bad under load!', but I had measured it with my Fluke DMM, it was good. So I 'T' connected the DMM to the PS, turned on the rig, and read 2.7Vdc?? I pulled out my 100W adjustable Ohmite power-resistor, hooked it up to the PS, and measured the output Voltage. The resistor got mighty hot and the DMM was reading a steady 13.2Vdc!! So that meant that the TS-440 was pulling down a 30Ampere power supply while in receive mode!! Specs claimed the Rx mode pulls around 2 Amperes, so something was shorted and the fuse didn't pop?? I checked the fuse and some moron (including me for not checking) had stuck in a 60A fuse!!! I pulled the covers again, and looked around for anything out of the normal, swollen capacitors, etc. Then I disconnected each of the internal power-system regulator boards, turned it on, and still the PS was being pulled down. However two of the three terminal regulators AN7805s were bad, one would move into thermal runaway after a couple of minutes. I replaced them with a couple of KA7805 (TO-220). Upon closer schematic scrutiny, revealed that the 13.7Vdc, after passing through a DC Input Choke Filter board was connected through the main power-switch directly into the transmitter section. Getting to the DC Input board was quite involved, but I got it our and sure enough there was a leaky 22,000 uF electrolytic on the board, C14. I pulled it checked it with an ESR meter and it was definately bad. Stuck in a new capacitor, put everything back together again, powered it up, and the 13.2Vdc was good but the radio still did not come alive, aside from making a newly heard buzzing noise from the speaker. I began measuring rail voltages on the the various boards and the digital logic boards had no +5Vdc on the rails. It turned out that the fellow who sold me the radio had removed the antenna-tuner, and had accidentally cross mated two connectors. Fortunately the power-supply did not do any damage as the connector was attached to an open circuit. I swapped the cables, turned it on, and poop-howdy!! It came alive. The display lit up, the VFO knob when turned changed the displayed frequency, volume control, pushbuttons, everything works. I ran the internal diagnostic test and everything appears to be working. I gompered together a bunch of aligator clip-test leads, about 20 feet worth, and tuned around on the radio and picked up a couple of hams rag chewing. There's lots of noise on the bands, and I was unable to tune WWV. I was able to tune the commercial AM bands and tuned in a powerful local radio-news talk station, but was unable to cause it to sound 'normal'. As soon as the (Amazon) diddle-sticks (tuning wands) arrive, I'll attempt my first radio alignment. I have all the tools, and the nerve!! Then another TS-440 became available, it has the internal antenna-tuner installed. I bought this radio for the purpose of being a parts-radio. It arrived with no top or bottom covers, missing the optical-encoder VFO assembly, no faceplate or knobs. I was hesitant to buy it because it had no s/n as the bottom cover was missing, but the seller's explanation was that It was acquired from the estate of an SK who fixed radios. Upon review, the parts radio is in really good shape, in fact better than the first one. So I bought the missing parts from W8EK who seems to be everywhere and the parts will be arriving shortly. I plan to restore this radio as well. Two's better than one. I'll mount one in my motorhome which I was going to git-rid-of, but now soon to become my rolling ham-shack (heh heh heh) and the other I'll use as my base-station. So when I start working on the second radio, I'll post as things progress. Well that's enough yak'n for now. 73 20_meters - km6oyh |
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