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NTE-7164 compatibility with NE/SA-602/612?

Discussion in 'Radio Circuits, Repair & Performance' started by KK4CUL, Aug 25, 2018.

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  1. KK4CUL

    KK4CUL Ham Member QRZ Page

    I had a pretty sweet Amazon gift card given to me and ordered some computer things I needed. I had a little over $30 left and bought some electronic components like capacitor assortments (ceramic, polypropylene, electrolytic of varying values), PNP and NPN TO-18 transistors cuz I like the way they look, bread and per boards, power transistors of the TIP and BD variety, etc. I was looking for the venerable NE602, but they are all out of stock unless I wanna buy an Air-band receiver kit for $25 or so. As fun as that would be, I just want the double mixer / oscillator part for other kits. Now, I can find a plethora of NE or SA602s on eBay for cheap, but for two reasons am hesitant. First is that I've heard on misc radio boards that they are a mixed bag of stability or quality, and I don't really feel like ordering on a separate site. After searching "double balanced mixer" on Amazon, I found the NTE-7164. It's pinout and logical "schematic" look nearly identical, including impedances and voltage range. Do any of you have experience with this chip, and if so, know if it is a drop in? I already purchased one for $10 (I know that's steep, but I had enough on the gift card given to me and shipping was free).

    I mentioned in one of my earlier posts that I have taken a schematic used for an AM BCB receiver kit using a TA7642 radio IC and successfully brought it up to the 60 meter SW band, but I heard the NE602 is more versatile and would like to design my own receiver with it since it has a wider frequency range. Please let me know if anyone has experience with it and can tell from the data sheet if it will behave similarly! Thanks and 73, KK4CUL

    PS - Here is the datasheet: http://www.nteinc.com/specs/7100to7199/pdf/nte7164.pdf
     
  2. WA3UCR

    WA3UCR Ham Member QRZ Page

    That datasheet looks identical to the NE-602/612. NTE markets replacement semiconductors, like RCA (SK) and Sylvania (ECG). This looks like your chip with NTE markings.
    I have bought many from China (Ebay) over the years and never had a problem. I always keep a few around for projects and tinkering - it's such a cool little chip and so easy to work with.
    Fake parts on Ebay do exist - for sure - YMMV....but I have had no issues with NE-612's that I have ordered from China.

    Anyway, the NTE replacement you have on the way should work identical to a NE-612, because it is a NE-612 with NTE markings.
    73
     
    KK4CUL likes this.
  3. KK4CUL

    KK4CUL Ham Member QRZ Page

    Thank you, WA3UCR. If this one works and I have luck with it, I will just order a handful on eBay in case one or two are not working. I look forward to experimenting with it once I get my TA7642 shortwave RX completed!
     
  4. K6CLS

    K6CLS Ham Member QRZ Page

    if you aren't stuck on using your gift certificate... Jameco has 602s in 8-DIP for $cheap. I have a tube of 20. hope to use them all before I expire!
     
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  5. KK4CUL

    KK4CUL Ham Member QRZ Page

    I will look into that, I just wanted to get one to play with. I am not that great at designing (relatively) complex circuits of my own yet, so didn't want to order a bunch to collect dust if I can't make this one work! I just had read about it in a lot of home brew receivers and thought it would be a good way to use of the gift card.
     
  6. KK4CUL

    KK4CUL Ham Member QRZ Page

    Got it from Amazon today! Looking forward to tinkering. So far, about all I have home-brewed are a couple one or two transistor amplifiers, a basic microphone preamp, a passive tone control board, a power-supply / battery switch with charging circuitry, a VU meter using the AN-6884, and miscellaneous attempts as AM BCB receivers.

    I have seen a lot of NE-602 ideas on the web, but a lot are WAY over my head! Does anyone know the basic components needed to use this as a simple receiver? I have a decent selection (~40-50) of 1/4w and 1/2w resistors, a whole box of ceramic, mylar and electrolytics, plus some larger value electrolytics purchased at Radio Shack, a dozen or so each TO-18 PNP and NPN BJTs, a few TIP31As, TIP120s, DB139/140s, 1n4148 switchers, LM386s, NE55s, etc.

    I can follow schematics fairly well, but I do struggle with with winding torroids. A friend gifted me a Softrock Ensemble with a bunch of SMT components and some tiny-a$$ torroids, but I am not that confident in my soldering skills for SMT components. However, any ideas of where to start would be great! I have multiple breadboards, some perfboard, a fine tipped solder pen, and patience so am willing to try (even if it's a single frequency RX!)

    Thanks in advance, if anyone is still watching this!
    KK4CUL
     
  7. WA3UCR

    WA3UCR Ham Member QRZ Page

    Do you have any test gear, like a scope or freq counter? A scope is really the number one tool for tinkering. That may determine what you can do with the chip, especially if you run into problems.

    Here's my last completed project with the NE-612's. It is a homebrew 40M CW QRP transceiver. It uses 3 NE-612 chips, RX mixer, product detector, TX mixer. LM386 for audio, and LM393 for the RIT circuit. The VFO is a JFET design and covers about 50 KHz, tuned with a varactor diode. It is a superhet with a 4 MHz IF. Power output is 4 Watts if the input voltage is 14 VDC, less with a battery. Built entirely from junk box parts, except for the programmable digital dial ($12) from Ebay. RX "hears" a -121 dBm signal (S1) with good signal to noise ratio. Full, silent QSK - a pleasure to use and it makes me chuckle with every contact I make with it ! Even the box is homebrew - made from double sided pc board material FR-4. It's not real pretty, but it works great - such a blast to use.

    Working on a 30 meter version right now - RX is done, working on the TX side now.
    73 and have fun. I love this stuff. What are you thinking of building?
    Bill
    DSCN6085.JPG DSCN6022.JPG
     
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  8. KK4CUL

    KK4CUL Ham Member QRZ Page

    Wow! That is beautiful!

    I do not have a scope, unfortunately. I just have a DMM and a few receivers. I was hoping to just start out very basic. Did not realize how complicated it could be! Basically, I was hoping to make a very simple RX, somewhere in the HF/SW bands. Frequency stability at this point isn’t required. I just wanted to play with it as I have heard many awesome things being built with it. I suppose a scope or function generator would be necessary down the line! Transmitting would we awesome, but a bit over my head ha.
     
  9. WA3UCR

    WA3UCR Ham Member QRZ Page

    Well, not exactly "beautiful" - but a typical HB project for me. I could have shrunk it down into a smaller package, but decided to use a board that I had laying around and was too lazy to cut it up. The entire thing was first built on a solderless breadboard and I actually made a couple of contacts with it in that state. In fact, I worked W1AW in that condition and a couple of guys that I know.

    I think you may want to look for a scope - it is really essential IMO for tinkering with HB stuff. Function generator not so much - but a RF signal generator is important for playing with receiver circuits. If you really like tinkering, save up for some test gear, then start populating your junkbox. Deals can be found at hamfests, or ask local guys (maybe at a club meeting). For receiver circuits you may need to pick up some toroids. I keep a stash of FT50-43, FT50-61, FT37-43, FT37-61 ferrite cores and T37-2, T37-4, T50-2 and T50-4 iron powder along with some larger diameter cores of the same mixes, like T68-2 and -4. All are available pretty cheap from Ebay. You might want to pick up a handful of trim caps too - you can see I used quite a few in my projects.

    The web is full of NE-612 circuits and projects. I built a crystal checker using one that only requires 3 or 4 other components ( and a scope or freq counter ).

    I started fooling around with these chips about 15 or 20 years ago. It took awhile to get the first simple direct conversion rx going - so there is a learning curve, but once you hear signals coming from something you have built yourself it's all worth it. I can remember being very excited when I got it working for the first time. Once you have the basics down, you are only limited by your imagination, the specs of the chip, and the components you have collected in your junkbox.

    Actually, building the transmitter section of the xcvr was easier than the receiver! It is really simple straight forward design. NE-612 TX mixer that mixes the 3 MHz VFO and a 4 MHz xtal to get the signal back to 40 meters, a JFET buffer, a 2N2222 driver and a class C final, 2SC799. It took more tinkering to get the receiver up to snuff than the transmitter - for sure !

    Have fun, and send me an email if you need help or have questions. I'm no expert, but have lots of experience.
     
  10. K6CLS

    K6CLS Ham Member QRZ Page

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