Nuvistor Tubes

[W2PFY]

Nuvistor Tubes  I wuz a bit curious if anyone out there ever did anything with nuvistor tubes such as build a transmitter or receiver with them? I have seen and owned factory made converters.The TV industry used them in TV tuners once upon a time. Other than that, what else do you know or have seen about them?

Best regards,

Terry

[w8khk]

Back in the early 60's I built a 2-meter converter with 2 6CW4s in cascade.  Also put one into a home-brew grid dip meter.

I once had a fabulous Fisher 500-C receiver that used a pair in the front-end.  So sorry I ever let it go.  But then again, the content received on the 3-meter band is not so great anymore either!  My earlier Fisher 800-C is devoid of these miniature metal tubes.  But after a re-cap, it is keeping the living room warm in the wintertime.

I have thought about using them for a microphone pre-amplifier, but now that FETs are so plentiful and inexpensive, what is the point?  

I have not built any transmitters with them, but that would be the ultimate in a tiny PW compact rig, say in a tuna-tin or maybe a band-aid box.  Do they still make them in metal, or only paper nowadays?  Sounds like a fun project idea!  How about a nuvistor VFO for starters?

An obscure source for nuvistors might be some of the older Tektronix scopes, that can be found for a pittance at fests, whenever we have them again.  The Tek 453 and 454 have a few, as do some of the plug-ins.  Seems sacrilegious to hack apart a good Tek instrument, but the 45X series is so plentiful, one would probably be forgiven.

[WBear2GCR]

Ameco outboard preamp used them.

There was a cascode plug in RF tube replacement using them.

For low level stuff now supplanted by solid state.
Still useful for situations where they might get blasted with high levels
of RF that would turn transistors into silicon wire.

Got a supply??

[KA3EKH]

There was a lot of surveillance, counter measurers and telemetry receivers built back in the sixties that used Nuvistors in the front ends for there low noise performance. Companies like Nems Clark and Watkins Johnson built a lot of the stuff. Not many people collect that stuff today, the WJ stuff is maybe more popular then the Nems Clark stuff. To bad being a lot of the old sixties vacuum tube stuff was ground breaking in its day but the solid state stuff by WJ or companies like Microdyne just blew all that stuff away when introduced and the wide band nature makes it poorly suited to Ham use so not much of it survived. Have a friend who has a rack full of Nems Clark stuff that was used by NASA back in the sixties who has been trying to get me to take it but just don’t have the floor space for something like that with no real use today. As far as I know all the ATP Weather satellites are gone or at least up on L band so not much use for something that receives in the 130 to 140 MHz band.
Sometimes wish I had more space but then again imagine no matter how much space you have you fill it up and always want more.

[w8khk]

I would really like to find a Nems-Clarke 1906 like this one:

https://watkins-johnson.terryo.org/history/Nems-Clarke/1906.htm

[Detroit47]

Lets not forget the Ameco pre amp I'm bad I missed Bears comment on Ameco

[W2PFY]

Lets not forget the Ameco pre amp

I forgot about that model. I have one at my camp that I used to use with my FT-101EE that was hard of hearing on ten meters. I don't know if there was a problem with that radio or if all FT-101EE are like that? Anyhow mine worked fine with the transceiver.It had relays in it that allowed it to work seamlessly with the 101. I remember that I somehow burned it out but I forgot how it happened? When it was working, it was fantastic! I need to get it on the work bench and see what the problem is? IT burned out, I walked away and it's still that way:)

Keep the examples coming guys.   BTW, I think Bear asked if I or we have any?


The link for eBay has a bunch listed and some are priced ok fine!

https://www.ebay.com/sch/i.html?_nkw=6CW4+Nuvistor+Tube&_in_kw=1&_ex_kw=&_sacat=0&_udlo=&_udhi=&_ftrt=901&_ftrv=1&_sabdlo=&_sabdhi=&_samilow=&_samihi=&_sadis=15&_stpos=12932-0616&_sargn=-1%26saslc%3D1&_salic=1&_sop=10&_dmd=1&_ipg=200&_fosrp=1

[w7fox]

Terry,
Back in the 60s I built the 420 megacycle transceiver from the 1964 handbook, which used one nuvistor and two transistors.  It seemed to work but the other ham who was building one never finished it.  I never  have worked anyone with it.  It sits on a shelf to this day.

Best regards,
Fox

[w3jn]

The Watkins-Johnson RS-111 used nuvistors for the front end and LO up to the early 80s; the Kahn RSSB-62/CV-1982 SSB converter used 23 nuvsitors including a pair of push-pull for the low level audio out.

[WA2ONK]

In the early '60s I had a Tecraft 2m converter that used a couple of them. I have a Clegg 22'er that uses one in the frontend.

[KD6VXI]

Polytronics build a business band / Cb (like the old Johnson radios, dual use) model called the Polycomm N.  They offered two models, one having a mechanical filter in it for 10 bucks more.  It was an early 60s radio, 8 channels I think (maybe 5), all plug in xtals.

It retailed for 219 dollars.  1600 smackers in today's money!

They where not common, at least in my experience.  I've run across one in 30 plus years spent playing with old radios, having owned a Cb shop for a couple years and yard sale scavenging.

A good radio, but it doesn't look like they sold many.   And with the price, I can see why.

--Shane
KD6VXI

[Pete, WA2CWA]

Out of the woodwork 

Almost any manufacturer that announced a VHF receiver or VHF transceiver from early 1960's on, designed their stuff with a nuvistor front end.
Clegg used them in a number of their receivers and transceivers. Clegg Interceptor(B) had at least five of them.

The majority of all the Polycomm rigs (CB, ham, Business) had nuvistor front ends.

Hammarlund HQ-110A-VHF and HQ-170A-VHF receivers used nuvistors.

RCA Ham Tips had two articles on a 2 meter transceiver using nuvistors and solid-state devices. They also had several other amateur-related homebrew articles using nuvistors.

Even the Japanese were using nuvistors. The Lafayette HA-410 10 meter transceiver, the HA-460 6 meter transceiver, and the HA-1200 2 meter transceiver all used nuvistors.

Both domestic and Japanese Hi-Fi manufacturers were designing nuvistor front-ends for many of the FM tuners and receivers.
Nuvistors were the top-end front-end design tube for several years until the low noise FET and MOSFET design parameters became more solid in specs and reliability.

[KD6VXI]

Good to see ya Pete, hope your doing well.

--Shane
KD6VXI

[WA2SQQ]

Interesting mention about the RCA ham tips article. The published a 2/10m transceiver that used a nuvistor converter for the 2m side. I have the prototype of that radio. Back in the 70s I worked 21 states on 2m AM and WAC on 10 AM with that radio. Used an ARC5 transmitter as the VFO for the transmit side.

[Pete, WA2CWA]

Good to see ya Pete, hope your doing well.

--Shane
KD6VXI

Doing OK.
Lot of people home over the last two months and everyone seems to want manuals 

[Pete, WA2CWA]

Interesting mention about the RCA ham tips article. The published a 2/10m transceiver that used a nuvistor converter for the 2m side. I have the prototype of that radio. Back in the 70s I worked 21 states on 2m AM and WAC on 10 AM with that radio. Used an ARC5 transmitter as the VFO for the transmit side.

Looking through the list of RCA Ham Tips, I didn't see a 2/10 meter transceiver.
Issues Spring and Summer 1965 had Transistors and Nuvistors in a 2M transceiver
Issue Spring 1962 had a Nuvistor 2 meter transmitter.
Lots of Nuvistor VHF and UHF converters in a bunch of issues.

[WA2SQQ]

http://n4trb.com/AmateurRadio/RCA_Ham_Tips/issues/rcahamtips3002.pdf

It was in the last issue

[Tom WA3KLR]

Great 'home-brew at work' design - boy, the stuff is really crammed in there!

[Pete, WA2CWA]

http://n4trb.com/AmateurRadio/RCA_Ham_Tips/issues/rcahamtips3002.pdf

It was in the last issue

Figures, my Ham Tips ends at Volume 29, Number 3, December 1969. 
Thanks

[W2PFY]

Here's a link to Antique Radio site where our man Pete has entered a lot of useful information.

There's even schematics that Pete has provided. Way to go Pete!

https://www.antiqueradios.com/forums/viewtopic.php?f=19&t=354353