2SK508 DATASHEET PDF

2SK datasheet, 2SK circuit, 2SK data sheet: UTC – HIGH FREQUENCY AMPLIFIER N-CHANNEL SILICON JUNCTION FIELD EFFECT. 2SK Datasheet PDF Download – HIGH FREQUENCY AMPLIFIER -CHANNEL SILICON JUNCTION FIELD EFFECT TRANSISTOR, 2SK data sheet. 2SKLK53 from NEC Corporation. Find the PDF Datasheet, Specifications and Distributor Information.

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I bought a used ICF in It had apparently been someone’s workshop radio, judging from the huge amounts of brownish dust inside and several paint sprinkles outside. I conducted a head-to-head comparison with my trusty SWG both just on the whipwhich resulted in my first ever “official” radio review. Head over to my receiver review corner in order to read it. Here’s a complete scanned service manual for the ICF While this is of adequate quality, my own scan of the regular non-L ICF’s schematic is somewhat better still: If you need a service manual in paper form, there are various sources that sell ’em.

I have mentioned a local one in the misc links section. After having studied the service manual of the ICF LI’d summarize the architecture of the set as follows:.

2SKT1B-A Renesas | Ciiva

The dataasheet features no less than four front ends: For FM and MW, this turns out to be fairly simple, signals from the whip antenna or ferrite rod antenna, respectively, are fed virtually directly to the CX mixing, demodulation and audio amp IC I wouldn’t be surprised if it also contained a function for walking the dog, hiwhere they’re mixed to Now to the most interesting part, the satasheet bands, where the receiver works with dual conversion: The “about” part is because the mixer takes its constant mixing frequency from a crystal oscillator with switched crystals of The “digitals”, by comparison, vary this 1st mixing frequency and thus can employ narrow crystal filters in the 1st IF to reduce IM3 by the 2nd mixer — but they don’t have to fear frequency instability as much as analogs.

After this, two cascaded and I suppose: This, BTW, uses a 2SKY FET and a variable mixing frequency that’s what you vary with the main tuning knob — a “digital”, by contrast, has a constant 2nd mixing frequency since the frequency variation part already took place one 2s5k08 earlier.

A general note on the somewhat unusual dual conversion concept: While it is remotely related to the well-known triple conversion Wadley Loop concept in that it uses a fairly wideband IF stage the first IF in this case and consequently has similar issues with strong signal handling if the 2nd mixer isn’t pretty good, it actually bears a lot more resemblance to another s concept, namely the Collins 51J-4’s for bands Sony chose the 1st IF of Drift is kept rather low as the tunable 2nd local oscillator only works in a limited range around 11 MHz.

The 2nd mixer in the older set is less prone to overload as well. And in fact, I think that much improved readout accuracy and improved stability were the main reasons for choosing this concept over a classic single conversion one, along with better image and spurious rejection.

In this form, it cannot reach the same raw reception performance as a “normal” dual conversion concept; this would have required both a tracking filter on the 1st IF and a beefier 2nd mixer. While being quite ingenious when originally thought up aroundit already was outdated by the time the ICF came out and inexpensive frequency counters would have allowed a conventional dual conversion datwsheet with ultimately better reception and readout accuracy if not the same stability, always a problem with wide-range analog tuned oscillators.

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These days, this receiver concept really is something for weaker signal areas only, and I would therefore hesitate to recommend buying a new receiver using it they typically do seem to have fairly good selectivity though.

Incidentally, the venerable ICFW isn’t a Wadley receiver either, just an almost “normal” dual conversion rx with a tuned front-end and bipolar balanced mixer, btw that reuses some FM IF filters for dagasheet 1st SW IF, with a crystal-based marker frequency generator kHz and a slightly and precisely adjustable 2nd LO frequency thrown in. The trick when tuning the rx is finding a marker het close to the desired frequency. The critical part in terms of drift remains the 1st LO. It will seem that Sony likes to refresh existing IC designs once in a while, replacing older ICs with new functionally identical ones, probably to accomodate for changed production processes.

The interesting part is that if you can’t find a datasheet 2ek508 one version, one that covers another version generelly will also do plus you can still buy at least the current iteration of such a chip in case a replacement is needed.

Not that much of a battery hog. I guess this set was supposed to mimic an analog not only in look and feel but also in power consumption, being geared more towards the traveler rather than the shortwave enthusiast who’d obviously prefer the ‘DS by quite a margin.

Main board schematic plus corrections and changes from supplement-1 [1. Looking at the circuitry, I would agree with the assessment of adequate, but dztasheet outstanding shortwave performance.

Combining a wideband frontend with an unbalanced first mixer — as found in these inexpensive sets — is not a very smart thing to do, as 2nd order intermod quickly becomes a major problem.

2SK508 Datasheet

Interestingly the preceding ICF-SW30 used a double balanced mixer, but its user interface left quite a bit to be desired. Here’s what Google Translation makes of it. The first one in particular was not minor, indicating that several bugs had to be worked out.

The resulting versions are:.

The original service manual bears a coppyright date of Partly but not solely due to all the different versions, the service docs are pretty thick, in stark contrast to the ‘s minimal service manual! In case you are wondering where the second AGC line used for post-preamp AGC went in post samples unlike its predecessor circuit, the opamp based AGC amp has only one outputlook at the first correction from supplement-1 — the datasheeet board schematic from the original service manual does not fully cover the changes.

This had me puzzled for a while. Should you experience audio distortion in the AM mode only, particularly with bass-heavy content, the AGC adjustment needs to be carried out. This is done by adjusting RV2 a trim pot near the upper right corner of the main PCB’s component side so that a voltage of 1. Sounds easy — however, fairly comprehensive disassembly will be required to get to this point, which is vatasheet entirely trivial see the next section as well as the linked Japanese page.

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I bought this set NEW from a Sony dealer inhave forgotten which year. It has always worked well until the last year or so, when the distortion on AM started to creep in, and finally got bad enough to make me get in to it.

My experience opening the set was not traumatic, I removed the 4 long screws marked by the arrows on the backthen working along the first seam of the back cover with a pocket knife, discovered I should pry the back cover away from the thin spacer that runs around the set. I forget if the plastic hook catches need 2ks508 be pressed in, or pried out, but the back cover came off without a fight. The track side of the analog board is now visible.

Suck the solder out of the hole for the ground wire that joins the 2 boards with a pump or wicking. There is a screw between the lower edge of the board and the battery compartment to be removed. Now, find the molded-in plastic hooks that hold the board in place, and release the board and lift it up.

The Sony series page: ICF, ICFDA/

If you want to go further, unplug the ribbon cable and fold the board back. The ribbon cable connector on the board should be a two-part locking piece that releases the cable when the upper part is pushed upwards, similar to what the SW has. I did this for inspection purposes, and when I had located RV2, I plugged it back in, and was able to operate the set with the board raised, so I could adjust RV2.

I did not get a VM accurate to 3 or 4 decimal places to adjust it, I just tuned a strong local AM mw music station, Listened on a set of High-Fi earphones with good bass response, and adjusted it for least distortion. It has worked like new ever since. That seems like the most sensible way of performing the adjustment, given that we want the best possible real-life AGC performance. This is far as I went with the dis-assembly, but it was obvious that all you have to do to strip the set completely, is unsolder the wires to the speaker and leave it behind, glued to the front panel.

If you want to operate the set out of the case, substitute another speaker, or use extension leads to the one in the case. There is no mechanical reason to remove the speaker from the case. It’s not in the way of anything. While the differences between various international versions were generally pretty much restricted to FM coverage starting at either 76 or The shifted 75m coverage also means that the eatasheet input tank circuit is peaked datssheet instead of kHz, which does not make all that much sense given that actual stations are typically found between about to kHz.

While I guess that it won’t make a night-and-day difference, you may want to re-peak L3 at about kHz, preferably when you’re working on such a set anyway.

ICF Additional information Datasheeg and internals. Created yyyy-mm-dd Last revision

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