All nuvistor rx or transceiver?

[W4OP]

I am mildly interested in building an all Nuvistor HF receiver or transceiver. I have not turned up anything via Google- although the RCA notes have a very interesting 2M hybrid nuvistor/transistor rig.

Anyone on the group know of something?

Tnx,

Dale W4OP

[KL7AJ]

Nuvistors aren't particularly suitable for transmitting...they are very low power low noise devices.

Eric

[KC9UDX]

I'm sure I've owned and probably even worked on sets with Nuvistors, but I'm pretty sure I've never actually seen one, or when I did, I didn't realise what I was looking at.

I have probably read the same RCA publication you have, because it sounds familiar. I always wondered why not all Nuvistor, and why only 2m?
I have to imagine though that there's probably nothing to gain by using all Nuvistors in an HF rig, other than size and power consumption (and heat dissipation).

I wonder what the availability of Nuvistors is? Also, what's the availability of those subminiature Russian tubes? I have a couple of those somewhere. I don't know enough about Nuvistors to say this, but, maybe the Russian tubes are smaller..? The ones I have are the size of a neon lamp. Obviously the power handling capacity is pretty low, but, the plate voltage is probably really low too.

[W4OP]

Nuvistors aren't particularly suitable for transmitting...they are very low power low noise devices.

Eric

Well, I'm not talking a 6146 class output. 7587 Nuvistors in P-P will provide a very nice 5W or so output with very low drive levels at VHF and more at HF.

Dale W4OP

[KC9UDX]

It's also a matter of quantity. You could then achieve 100W with 20 such pairs of 7587s. Transistors didn't used to be good at handling power either and that didn't stop anyone.

[KM1H]

Nuvistors were never known for signal handling and AGC action since they are all sharp cutoff.

The Clegg Interceptor 2 used quite a few of them in several stages.

Arguably the best tube HF receiver would start with a 6EH7 RF and a 6ES8 Pullen mixer (A 7360 is also a good mixer choice)

Carl

[W4OP]

Thanks Carl,
While I have built a lot of tube gear- I have not designed all that much. I still have to think of a MOSFET and then convert back!

Dale W4OP

[K9STH]

The Nuvistor was used in a number of amateur radio VHF units. The Heath SB-110, SB-110A, and SB-500 all used Nuvistors in the receiver "front end". The Hallicrafters HA-2 and HA-6 transverters used Nuvistors as the "front end" of the receiving converter.

There were quite a number of VHF receiving converters that used Nuvistors.

When they came out (as r.f. amplifiers for television tuners) they were the "cat's meow" for use in VHF and UHF receiving converters for amateur radio use.

Glen, K9STH

[WB2WIK]

I think Bob Mendelson (sp?) W2OKO wrote an article on an all-nuvistor VHF transceiver, running low power (maybe 500mW or something for TX). He used to write a lot of the amateur technical tips for RCA, and was a semi-neighbor of mine in NJ.

I remember an article like that but it might have only been in the RCA bulletin and not published elsewhere. Long time ago.

[W4OP]

Good memory Steve,
The RCA papers are on-line. OKO designed VHF converters, transmitters and a 2M transceiver all using Nuvistors. The link to the ambitious transceiver is at:
http://n4trb.com/AmateurRadio/RCA_Ha...amtips2502.pdf

Dale W4OP