I've found what I'll need, Charlie, courtesy of Andy Ikin! Thanks to all for the assistance on this "project"! 72, Jim Rodenkirch K9JWV
> From: charlie-cunning...@nc.rr.com > To: w...@arrl.net; rodenkirch_...@msn.com; topband@contesting.com > Date: Sun, 25 Aug 2013 15:55:21 -0400 > Subject: Re: Topband: Anyone have a boat load of J-310s? > > Jim, > > If you really have trouble getting some J-310s, let me know. I'd really > have to hunt -probably out in my garage. The J-310s that I have, if I could > find them, are, I expect, at least 20 years old and pre-date the shenanigans > that Paul is warning you about. The ones that I had, are, as I recall, > either ON Semi or NSC. I probably should find mine, I guess. I bought the > JFET version of the old AMECO preamp, from my friend, Bill, K4CIA, so I > might need some spares someday. The vacuum tube version of the AMECO preamp > didn't have those vulnerabilities, and worked great on all the low bands up > through 30m, for the same purpose that you are using yours for. > > Paul's giving you some good advice. That's why I asked if you had tried > Digi-Key. GL! > > 73. > Charlie, K4OTV > > -----Original Message----- > From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Paul > Christensen > Sent: Sunday, August 25, 2013 2:44 PM > To: James Rodenkirch; topband@contesting.com > Subject: Re: Topband: Anyone have a boat load of J-310s? > > Jim, > > The major semiconductor manufacturers (e.g., Fairchild) who once > mass-produced JFETS in TO-92 style cases have now "obsoleted" most of them. > This occurred approximately 2-3 years ago. When shockwaves of the news hit, > > many folks (and the on-line bottom feeders), started hoarding the remaining > supply. Even the SMD versions are now in danger of going obsolete. > Presently, only InterFET Corporation and Linear Systems appear to be > manufacturing both through-hole and SMD versions of high-performance JFETs > although their per-piece prices are very high. Before the wave hit, I > purchased hundreds of various JFETs in TO-92 style cases -- J310s being one > type. You're welcome a to a few. True, in many applications it may not > make a big difference between say a J310 and MPF-102, but it unnerves me > when I don't know exactly what I'm using in a circuit. > > Be careful when sourcing any semiconductor. As you noticed, JFETs are widely > > available on the Asian market but when making a purchase through small > on-line retailers - and the big auction site, it's not possible to trace the > > supply chain of the component to its origin. For example, some Toshiba > low-noise bipolar transistors are in fact re-labeled 2N3904 devices. Unless > > the purchaser has access to a curve tracer and a means to perform critical > noise and frequency response testing, one is left to trust the seller for a > clean "chain of custody" between the time of manufacture and point of sale. > When China is the only source of many TO-92 JFETs, the red flags are up (no > pun intended). Because of this, I have only purchased semiconductors direct > > from the OEM or through well-established distributors including Newark, > Mouser, Digi-Key, Arrow, AvNet, and Allied. For an interesting perspective > concerning the severity of the counterfeit semiconductor market, see the > following report issued by the Semiconductor Industry Association (SIA): > > http://tinyurl.com/l9hqpw6 > > Let me know if you're address is currently good on QRZ. > > Paul, W9AC > > > ----- Original Message ----- > From: "James Rodenkirch" <rodenkirch_...@msn.com> > To: <topband@contesting.com> > Sent: Sunday, August 25, 2013 9:16 AM > Subject: Topband: Anyone have a boat load of J-310s? > > > > > > The J-310s in my little preamp are kaput - I looked at Mouser but the > > shipping costs are way too high for a couple of little Jfets - any body > > have lots of extra J-310 (or equivalent) they could spare? What ever your > > costs would be, including mailing them off, would be far cheaper than what > > > it would cost me to buy them outright! > > > > Thank you, in advance, for any help -- reply off line works good for > > me....72, Jim Rodenkirch > > > > _________________ > > Topband Reflector > > _________________ > Topband Reflector > > _________________ > Topband Reflector _________________ Topband Reflector
