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Hi! My conclusions there is one major criteria: How you impliment the design. Thinking along the design I remembered the standard analog VFO from Yaesu of bygone era. Two of my rigs FT107 and FT707

I released a "near" final software revision and put it under files section. I also put a software manual and an updated PLL design. I put the source code under the GNU public license with the aim

Yes it did yeild both lower noise and better gain. That still does not make the 2sc1815 a good transistor at more than 1/10th it's Ft in other than common base circuits. However there were

I dont agree. PCT process is newer than used for 2n2222. As far as I remeber of some article from 1982. This gave lower capacitance and noise than usuall transistor technology.

Max I think you did not understand my comment. I was referring to the fact that the 2SC1815 is very readily available in Japan...even more so than the 2N2222 is in the US, and probably the rest of

over years, i have visited kazuhiro's site. his work output continues to amaze me each time. he experiments fearlessly, then documents it all too. quite a volume of work. i find his designs

Hello, Yes 'OZL is a fantastic and very active constructor. Indeed I've been aware of his projects for many years now. The site for JF1OZL is one of about 40 I have bookmarked as they represent

JF1OZL in most of the constructions even on 50mhz is using this type of trasistor. As with the increasing of colector current ft getting higher. Also comon base ft is several times bigger than comon

Hi The 2SC1815 is the 2N2222 of transistors in Japan. It is even more plentiful and readily available there than the ubiquitous 2N2222 is in other countries. While they are usually of quite high

The 2SC1815 is a good device but it's Ft is only 80mhz. For HF VFOs that is adaquate but for the BITx if it may be a bit weak. Other devices of the era are the 2sc784, 2sc930 and 2sc945 all good and

on only BJT lines. A good BJT can be excellent but most BJT designs are aimed at high IP amplifiers. I've built one radio that used them MRF5xx series in a norton push pull config with IP in the

2sc1815 is toshiba pct process based transistor. so this mean lower capacitance and noise figure. this japanese design remind on comon base vfo used in the 70's in swan trx. schematics are in file

Hi! A DG MOSFET would certainly be an improvement. I had been thinking on only BJT lines. Rather than purchase them from mkt I normaly salvage them from old defuct TV tuners. The SMD BF989 or the

HI, Catch up how? I have two 20m SSB home brew radios one being BITx and the BITx for 6M makes the fifth homebrew for that band alone. I can add a few tube design I've done as well for HF. I

Hello, issue arises only due to varying characteristics of same devices available worldwide. Even within the USA there are poor spec parts problems and availability issues. limitation to what we

Hi! As far as BITX design is concerned it is well done. The IF gain issue arises only due to varying characteristics of same devices available worldwide. Where noise figure is concerned under

This morning I tested the 6m power chain. Results are very good with more power than expected. When integrated on the bench a two tone SSB signal nets 4.5W. I made the first local contact after

Thanks, Ashar! I think that Allison might need to catch up to you, too. The Eternal Squire

wrote: Not useful. If you'd used a accurate voltmeter or DVM you would see more like 2.7V emitter and 3.4V on the base and that small difference can be telling. 25/5=5, way low. for 5MV in I'd

Hi, I've found the MSP2222, PN2222, 2n2222A to be interchangeable assuming good parts. However, depending on the source and how they got in to the product stream they can be out of spec devices. A