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jst 245 instruction manualMost of my repairs have some curious story behind them and, this time, it was not different!. All started when a ham friend took a JRC JST-145 to my shop to add some parts from a 'similar' parts rig he had (which turned out to be a JST-245). Parts were no less than the Auto Tuner circuits (three PCBs and some cabling), as it was an option on the JST-145 but standard on the JST-245. With the 145 came also a Service Manual and a User Manual, valid for both 145 and 245. So I tried to get the auto tuner working but it seemed to be defective. One day, just in case I could do something else with the parts unit at home, owner took it to my shack. It was a JST-245, with the Auto Tuner assemblies removed (obviously!), missing Main Power Supply, missing screws and somewhat dirty. He told me it had previously been at several shops but it had been impossible to repair. As I had already played with the JST-145 and I knew its wonderful low-hiss receiver was exactly the same in the JST-245 (except for the 50MHz band, only present in the 245), I felt it was a pity to trash that unit. I looked in detail and there were clear signs of some job done to it. And it was not a very good one! A more detailed analisys of the rig's condition revealed the following: Incredibly, set fighted to power up and I could hear some noise coming from the (cone broken) speaker. Everything digital seemed to be working fine. I could receive signals generated with another transceiver (checked in several bands) and also directly from my Hewlett Packard HP-8640B, but set was definitely deaf. And I mean DEAF: it needed about 100mV (!) at the antenna terminal to move the S-meter. So, as only useful part for the poor JST-245 was not working and owner wanted to sell his JST-145, I offered him some money (not too much but, considering rig's condition, a fair price!). And the orphan rig was mine:-). This was the birth of a true Winter Project!http://www.siapsrl.com.ar/resources/original/1951-ford-8n-owners-manual.xml
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Finding an starting point in this kind of repairs is somewhat difficult due to the large amount of work to do. But it seems natural to start with the receiver section so I did that way. It is a large PCB, which fills most of the transceiver horizontal area. It is mostly SMD but there are also some PTH (pin through hole) components and a lot (and I mean a lot!) of connectors going to it. Just by optical exploration, I found that several components had been replaced with sometimes better and sometimes worse workmanship: some were barely visible and other were loosy jobs. All in all, a lot of work had been put on it by somebody but, obviously, had not completely fixed the rig.Some diodes, which turned out to be SMD double units, were replaced with non-SMD parts (just one diode!). But checking schematics I found that one section of the diode was unused so replacement could still be good. This was the case of CD146 (HSM88S). Another replaced diode was CD152 (RD5.1M-T1B, a 5V1 zener). Several other parts were just replaced and checked fine with the DVM in diode mode, as TR11 and TR72 (2SC2712Y), TR9, TR84 and TR100 (2SC3398). Other parts seemed replaced but could not be checked that way, as IC35 (UPC2002H). I also found some missing parts as CD169 (1SS184) or C640 (33pF ceramic cap). There was a damaged transistor, TR6 (2SC2954) and an associated resistor R102 (15 Ohm) which was open. These are shown in next picture. Checking schematics I found that a damaged TR6 meant transmission chain was broken. Well, anyway, as Power Amplifier was shorted, it was not a big trouble. Other faulty or missing components were in non crucial stages (as VOX circuit) so they were not the cause of the rig deafness. I resoldered some components which had bad soldering jobs and also removed shorted TR6 and faulty R102. A new capacitor was also put in empty C640 location.http://getbettersales.com/userfiles/1951-buick-shop-manual.xml It had of course same failures than before but now I thought there was nothing seriously damaged and started following signal path.I knew there was a problem in the Antenna Switch Unit so I took it out of the chassis. Checking schematics it was obvious that the signal did not flow through the main relay K2 (NR-HD-12V, a reed relay). So I took it out and replaced it by a bridge on its normally closed contacts. But rig kept deaf!. Checking a bit more, there was another relay shitching same time than K2 and it used a common transistor TR2 (2SC2712Y) to switch both. Of course, it was dead and was replaced by a BC857C. I fixed this with a 1K resistor instead of the K2 coil and, finally, signal passed through relays. Good! Once here, I had an almost working receiver.It was exactly same effect than slowly reducing RF gain. So S-meter started to climb up to about S9. I had an inspiration and found that pressing AGC button for some seconds turned it OFF (yes, I should know it if I had carefully read the manual!). And, once AGC was OFF, receiver not longer reduced sensitivity. In fact, it was working really fine and was able to hear up to -135dBm or so. As the JST-245 is a complex rig, AGC circuit is also a complex one, with a couple of analog bidirectional switch arrays controlling which components are on-line for each receiving mode (SSB, AM, FM, CW). Service manual did not help on this subject and schematics just shown IC16 and IC17 (both MC-14066B) sections but provided no indication about which modes activated them. I needed to find that, so I checked with the oscilloscope and got this table: There were some sections (IC16A, IC16D, IC17B and IC17D) which selected other things. Playing with the rig I found that IC16A, IC16D and IC17D were active only if mode was AM. Ok, so this gave me some clues about what could be wrong. But checking sections which were only active with AGC FAST or SLOW did not revealed the problem. All seemed to work fine.http://superbia.lgbt/flotaganis/1653167411 Some more troubleshooting led to a more obscure failure: IC17D section, which was theorically active only in AM mode, slowly leaked in all modes, building up the voltage which reduced RF gain.At this stage, I had a working SSB receiver and a partially working (only with AGC OFF) AM receiver. I started to check other functions. From another rig, I had an optional Monitor Unit available (this unit let's you monitor 9.455MHz IF on tranmission). I was amazed to find that it worked!. So TX chain, up to that point, was working. Great finding!. I checked up to the missing TR6 transistor (which is a 70MHz IF point) and signal went that far. Good. VOX circuit, as there was a missing diode, did not work. COMPRESSOR worked fine, though. RF AMPLIFIER was also found working. I had not yet checked FM. Upon doing that, definitely, it did not work. Another thing to look at. All in all, I was happy. So happy that I decided to check BBC at 9410kHz. I got no signal in AM nor in SSB!. Bad thing, as it was being received perfectly in my Yaesu FT-890. Then I checked, with a -73dBm (50uV) signal (S9 calibration level), all the receiver range. I found that it worked fine from 100kHz to 54MHz except for 7.500 to 9.999 kHz. Checking Service Manual, only reason to this seemed to be a faulty DDS (nooooo!) or some VCO trouble. Praying for the later to be truth I found that VCO check voltages were out of range (also, an unlock LED lighted when receiver was in the faulty frequency range).Now there was the FM trouble. As FM signals follow a different path and use also different oscillators, this time repair was also fast: when in FM mode, a LED announced an unlocked PLL. Adjusting CV12 trimmer brought back FM. Yes, at the beginning of August 2007 I got an e-mail from a ham in Canary Islands who had a damaged JST-245. We talked by phone and we agreed in an swap, so I got another faulty 245. This time, what was for sure unworking was (surprise!) the main power supply and also secondary power supply.http://www.loutrainers.com/images/737-800-flight-crew-training-manual.pdf Both had been fried connecting the unit to 240VAC, being internally jumpered for 120VAC. All other parts could work but, as someone had been playing to get it working, using a PC power supply and other tricks, we were not sure. Unit finally arrived and what I found was a nice front panel, with just some scratches in the frame and a generally nice looking unit, except for some oxide in metal parts ( later I found that it had been used in a merchant ship ). It was a more recent unit than mine (serial RG03571 versus RG01346), made about 1995. Here you have some pictures of this unit: My 245 was almost working on receive and transmitting a faint signal (just what is needed at the input of the Power Amplifier (PA) unit).If it was faulty, most of the joy would vanish. But first I needed to fix some damage in the PA fans, which somebody had crushed and almost cut: Things started to look fine. Next step was to check all transceiver functions. And then some problems arised: microphone PROCessor didn't work. And I found that I was using the rig WITHOUT ANY OUTPUT BAND-PASS FILTERING!. Yes, as Auto Tuner (AT) in my unit was faulty (I had checked it in a JST-145), I had removed it and connected directly the PA output to the antenna relays PCB.And, as I suspected, it didn't work. I replaced it (all three PCBs: first sensor one and then relays and control ones) and ended with a working AT. Another milestone covered!. Here you have some pictures of the process: There is a problem with the 245 SWR indication: it is taken before AT so you don't know the SWR after the AT. But I found an easy way to know it did something: an external watt meter showed improvement (a bit more power) when AT was ON. Ok, so now my JRC hybrid worked fine on TX (I did a couple more QSOs in 20 and 40 meters).I checked the RXTX BOARD in the second unit. It looked fine and was a newer revision than mine (D versus B). So I got out all the connectors (about 50 or so!). They are numbered, which saves lots of time doing it by yourself. Here you have the RXTX unit once it was out of the second 245: But there was NO power output. ZERO. None.:-(. Then one of the worse moments in the repair happened, as I was eager to find the problem. I was not able to locate the Service Manual, and I looked for two long hours!. I am sure it should be somewhere in my shack (which is, despite high volume of items, very well organized). But no way!. So, as a last resource, I looked in the WEB for info and located a poor quality schematics which included a block diagram. As I had already fixed my 245 (but some years and some hundred repairs ago!), looking at the block diagram, I thought almost in first moment in the uPC1677 amplifier. I checked input and output and, yes, it was KO!. Luckily, my other unit had same failure and I had placed the replacement in a socket. So I removed bad one, put a socket and plugged the known-good amplifier.So I toggled the DIP switch and, voila, 150W:-). Once there I thought about repairing the internal power supply.But, knowing that it is the weakest link in the rig and that the external power supply I use is about three times more powerful (so it is in no way stressed), I decided to keep it this way by now. But I needed to do some work to have a FT-1000MP Mark-V-like external power supply. And best way I devised was to use the rig power switch to control the external power supply. So I would need a 4 wire cable: 2 for the VAC from the rig switch to the PS and 2 for the 48VDC from the PS to the rig. I needed to drill a 10mm diameter hole in the back of the rig for the cable, but I found this was a minor problem, as it could be later plugged with a cover, if needed. Here you have some pictures of this process: I will add more information as I work more on the JST-245. Thanks for reading! Please, let me know if you can help me locating anything. For example, the grantee code for FCC ID: CKEJST-245 is CKE. The remaining characters of the FCC ID, JST-245, are often associated with the product model, but they can be random. These letters are chosen by the applicant. In addition to the application, the FCC also publishes internal images, external images, user manuals, and test results for wireless devices. Purchase on Amazon:See 47 CFR 1.2002(b) for theAll of the statements herein and theIn accepting a Grant of Equipment Authorization as a result of the representations made in thisIf the applicant is not the actual manufacturer of the equipment, appropriate arrangementsIt is understood that the letter of authorization must be submitted to the FCC upon request,Click an above application to view details Bldg. B Suite 201B Seattle, WA 98134 United StatesClick an above grant to view details. Please do not offer the downloaded file for sell only use it for personal usage. Looking for other manual? For this no need registration. May be help you to repair. You could suffer a fatal electrical shock. Instead, contact your nearest service center. Note! To open downloaded files you need acrobat reader or similar pdf reader program. In addition, Also some files are djvu so you need djvu viewer to open them. These free programs can be found on this page: needed progs If you use opera you have to disable opera turbo function to download file. If you cannot download this file, try it with CHROME or FIREFOX browser. Translate this page: Relevant OTHER forum topics: Pioneer CDJ-1000MK1 lemez olvasasi problema Adott egy Pioneer CDJ-1000MK1 cd jatszo. Olyan hibat produkal, hogy nem hajlando beolvasni az irott cd-t, visszakopi, viszont ha beleteszek egy gyari cd-t, azt beolvassa, majd miutan kiveszem es ujra probalok beletenni irottat akkor mar olvassa tokeletesen azt is, meg a nagyon karcosakat is hiba nelkul. Viszont ha kikapcsolom es vissza, akkor megint nem olvassa. Ha eljatszom megint azt, hogy belerakok egy gyarit es utana irottat, akkor megint mukodik. Mi lehet a gond? Elvileg 1 eve volt fej cserelve, meg ha rossz lenne a fej, akkor egyaltalan nem olvasna az irottat. Keresek olyan kollegat aki ert a JABLOTRON tipusu riasztok beallitasahoz (megoldva) Sziasztok. Kaptam egy ismerosomtol egy riaszto berendezest sok sok hozzatartozo kutyuvel JABLOTRON tipusu es ennek a beallitasahoz szeretnek szakmai tanacsokat kerni. A kozpontja egy JA-101K tip. Ha valaki tudna ebben segiteni illetve ismeri ezen eszkozok beallitasat es tudna segiteni azt szivesen elfogadnam. KENWOOD TW-4000A Freq Unlock Szervusztok. Egy kenwood tw-400a tip. Jelenleg egy egyszeru nyitassal 141-149 MHz-ig megy. Az irodalom szerint viszont letezik egy olyan lehetoseg, hogy 118-174 MHz-ig mukodjon.Pedig a PLL tudna. No ha valami otlete lenne valakinek, azt megkoszonnem:) Saeco SG 500 viz atfolyas erzekelo hiba Saeco SG 500 viz atfolyas erzekelo hiba. A panel szerintem nem erzekeli a viz atfolyas erzekelo jelet es nem allitja le a pumpat. Atfolyas erzekelot csereltem, de a hiba megmaradt. A panel szama: cod 0870.601You can write in English language into the forum (not only in Hungarian). Hello Dear Martinius. Hope I can help you. Take a look at my home page. Press on the JRC-TX button. And see below this page, which JRC JST-245 manual downloads I have. Remember this page is always under construction. And if you not can find what you are looking fore.Regards and 73' Cor L. van Soelen PG9HF. In this page you find schematic, users and instructions manuals, service manuals, technical supplement, leaf leads and other good stuff. If you have some stuff that not is listed here you can donate this by contact mods.dk. And when you click on the file or icon it will count as a download. If you want to see manuals from other manufactories you can click on the manufactory menu in the left side. You can also click here to see all the manufactories that mods.dk have manuals, schematics or other files from. Tuner settings are automatically stored in memory for fast QSY. Three antenna connections are user selectable from the front panel and can be stored in memory. The general coverage receiver tunes from 100 kHz to 30 MHz plus 48 to 54 MHz. Excellent I.F. bandwidth flexibility is assured with the variable Bandwidth Control. This permits the standard 2.4 kHz filter to be narrowed continuously to 800 Hz. Narrow SSB and CW filters for the second and third I.F. are available optionally. Other interference rejection features include Passband Shift (PBS), dual noise blanker, three step attenuation, I.F. notch, selectable AGC and all-mode squelch. Notch tracking is automatic. Very low phase noise is achieved through a single crystal Direct Digital Synthesis system. The keypad can be used for band selection or frequency input. The rear panel has three antenna inputs.Two separate VFOs are featured for split frequency operation. Memory registers store most recent VFO frequency, mode, bandwidth and other important parameters for each band. Each of the 200 memories stores frequency, mode, AGC and bandwidth. A built-in RS-232C interface facilitates computer control. The heavy duty, built-in power supply insures reliable and continuous use. The ergonomic layout, colored LCD display and thoughtful placement of controls ensure ease of operation. For a complete technical review of this product please see the September 1995 issue of QST magazine. Mic not included. Too low resolution, too much grey or unneeded 16 million colors information, or with nasty stains. PDF's over here are optimised where possible, cleaned and edited versions. And with additional repair, update and alignment info.The JST-100 or JST-125 (20 amps, first version) supply unit. Completely stuffed and edited version.Again some cleaning and upgrading by me of the original scans.PE1ABR edited version. Check and align only the 10 and 70 MHz ref and the PBT and HF compression mixer oscillator on 9.155 MHz, NOTHING else. ONLY standard A4 pages. Easier for printout.ONLY large A3 pages. Some cut in half pages are graphically merged again. No glue needed. Ideal if you print them on full size in a copyshop. So also easier for printout.There is nothing better to be found. Also see a next item for a much better CCD-48A memory diagram. ONLY print to A3 size. You definitely need the scissors and the glue pot to glue the A3 sheets together in two long wallpaper rows. A large number of circuit ideas can also be found in the successor, the NRD-515 The images were 100x too large in kilobytes and in the PDF 20x. Here the same sharpness in 600 DPI, but now in 2 colors TIFF in the 20x smaller PDF A datasheet of a very peculiar CMOS 4x 8bit memory IC - the 4039, used in this deviceComplete manual with diagrams A cleaned version of the datasheet of the used power beam tetrode 8122. Three of them are in parallel.Apart from also a lot of damage in the JST-100. Is it hopelessly damaged. Or is there any chance for success. This also doesn't obstruct the normal airflow slits. Vertical mount didn't fit at all. Due to a big lack of space the circuit board also got a different position. Also added a set of inrush reducing NTC R's and a VDR to absorb switch-off spikes. The switch-on with a relay is now realised with a much safer approach. I used a little second low voltage transformer to keep the on-off switch circuit separated from hot mains. The toroid manufacturer output already had taken account for voltage drop, I also did when ordering a Amplimo 88043 toroid with 2x 17V AC. So the voltage was a little too high!! To reduce heat a negative winding is added (4 wires 1.5 sq. mm in parallel) to lower the secondairy output a little. By using 0.5 V per winding, I added 3 windings to reduce it with 1.5 V AC. It seems also possible now to use a toroid with 2x 15V AC and to ADD one or two windings if a little higher voltage is needed! It also should be a little over dimensioned to avoid overheating. Take care: the NTC's become HOT, use a glassfiber cover board, and the VDR might explode, so encapsulate it in shrink tube. See the pictures below. The tracks were all vaporised. And a flashover in the on-off switch to the circuit of the 74LS123. This IC was also blown, happily not more. One on-off switch section was for mains, the second for internal on-off (timer-)control. By using an additional modified small (adapter) transformer for making the 12V DC and a new low voltage relay (with 16 amp contacts!) for the on-off circuit it is a lot safer now. The extra transformer is situated between the big electrolyte and the board, it's a small black block with removed mains contact pins. The new on-off circuit is galvanically separated from everything, but has a static discharge to ground. See the extra PDF drawing, made graphically with original JRC symbols. Now it looks like JRC drew it themselves. And YES, all is working again!Due to this list with tune info some minor roundup bugs removed.This will give 8x 24 channels in place of the original 1x 24. If you look at the neat way it is added you wonder why JRC didn't do it this way. PDF with binary coded decimal add-on universal (new) switch board for NDH-515 ZIP file with Gal array decoders - EQN and JED files Circuit diagrams are for a slightly (minor) different GAL version as NDH-518 PDF with circuit diagram GAL expansion for NDH-515 memory unit. It may not display this or other websites correctly. You should upgrade or use an alternative browser. The secret here (with the 756Pro) is that the 756Pro actually draws a very small amount of current (for timer-on function). So if your leave your 13.8 VDC (battery or power supply) ON -- but just turn the radio OFF - it operates -- as you expect. IF you remove the 13.8 VDC (turn off your DC power supply to the radio) -- then this occurs. Just like instant on TVs (ugh). Your battery is likely a 3 volt COIN CELL - about 20 mm in diameter, such as the very common CR2032. It MAY be a solder tab (soldered to PC board) verison - instead of a battery holder. w9gbI've had the rig apart a couple of times but not needed to completely romove the front panel for the repairs I made. I did not see the battery although I was on the look out for it as I would have replaced it if easily spotted. It must be somewhere on the front PCB near the display processor I would expect. If your still struggling someone on the above might know 73 de M0BXR IanRegister for a free QRZ account.