Call Search
     

New to Ham Radio?
My Profile

Community
Articles
Forums
News
Reviews
Friends Remembered
Strays
Survey Question

Operating
Contesting
DX Cluster Spots
Propagation

Resources
Calendar
Classifieds
Ham Exams
Ham Links
List Archives
News Articles
Product Reviews
QSL Managers

Site Info
eHam Help (FAQ)
Support the site
The eHam Team
Advertising Info
Vision Statement
About eHam.net

   Home   Help Search  
Pages: [1] 2 Next   Go Down
  Print  
Author Topic: NEW MANUFACTURE TUBE TYPE RADIOS  (Read 1891 times)
N8FVJ
Member

Posts: 692




Ignore
« on: July 25, 2001, 02:03:15 PM »

What would the ham community think about starting new manufacture tube type transmitters and receivers with an older, known name. Tubes used in audio applications perform well and are still manufactured today. A CW transmitter, AM/CW transmitter and a AM/CW/SSB receiver is very possible. Parts are not an issue. Cost would be reasonable and a kit version available.
Logged
WB2WIK
Member

Posts: 20545




Ignore
« Reply #1 on: July 26, 2001, 11:01:54 AM »

Interesting idea, but I don't think there'd be much market for it.  The market for high-end vacuum tube audio equipment is miniscule, which is why the prices are so high -- and there are millions more "audiophiles" in the world than there are hams.

Also, "new" circuit design based on tubes is nonexistent; thus, performance of a brand-new design for 2001 would be about the same as the older tube stuff from Collins, Drake, Heathkit, et al. 30 years ago.  Where would improved performance come from?  It cannot.

Since a new design would not be superior to those existing in the 1970's, it would be far less expensive to simply buy, restore and use the old gear, much of which was incredibly well designed.  How would I make an AM transmitter today that could perform better (that is, sound better on the air) than a Johnson Ranger or Valiant, or Heath Apache, or Collins 32V?  I couldn't -- it would take financing a transformer shop to manufacture high-powered modulation transformers that haven't been made in decades...

However, if there are venture capitalists nutty enough to finance a new amateur radio manufacturing venture based on vacuum tube designs, I'd happily offer consulting services for circuit design work.  I was pretty good at it back in 1970, and still have my old vacuum tube handbooks...!!

73 de Steve WB2WIK/6
Logged
N8FVJ
Member

Posts: 692




Ignore
« Reply #2 on: July 27, 2001, 02:06:55 PM »

The market would be very limited. Dennis Had of Cary Audio has done very well in the limited tube type audiophile market- although audiophiles do seem to have money to burn. I do not know if this would make money or not. 1000 orders over two years would work. As for mod iron, no problem- I can build these now. Already have a facility- paid for! A serious high performance tube type receiver would never sell- buy a Drake R8 (cheaper). A Collins 75A4 would cost about $2000 to build and the tooling costs are not included yet. An inexpensive 'fun box' for simple communications at a low price may sell. I guess about 50% of older tube type equipment sales is due to hams wanting a rig they could not afford when young. The other 50% are bored or curious.
Easy to improve on an existing, but somewhat limited receiver design. For example, use xtal lattice or ceramic filter(s) instead of I.F. cans for selectivity. Better noise limiter? Sure. The receiver would be simple, but selective and sensitive. Every control must work well and even feel right. Transmitters, very simple. Must market a kit as well- yes, need to get a 'held harmless' signoff for the high voltage issue.
Would this work, I am not sure.
Logged
WB2WIK
Member

Posts: 20545




Ignore
« Reply #3 on: July 27, 2001, 02:23:56 PM »

I just don't think the stuff would sell well enough to cover the investment of setting up any manufacturing.

I know Denny Had, K8KXK -- as you probably know, he used to own & run "Dentron" back in the 1970's.  And I think he found out that even that roller-coaster ride, which probably peaked in success back in about 1974, bottomed out quickly and went belly-up.

To run a small business as a sideline venture, or a hobby, is one thing; but to make a real business out of it is quite something else.  I wish I had time for the "hobby business" thing...it would really be a lot of fun.  Sigh.  Maybe in retirement!

73 Steve WB2WIK/6
Logged
N8FVJ
Member

Posts: 692




Ignore
« Reply #4 on: July 28, 2001, 11:30:58 AM »

Steve, this would be a sideline business. I am not sold on this idea, but a thought. Older gear has to 'dry up' a little more. I think this might happen, we will see. Tnx for comments.
Logged
AUG4EXAM
Member

Posts: 16




Ignore
« Reply #5 on: August 06, 2001, 02:54:59 PM »

I am getting in, and am looking a cheap tx for cw.  When I look at all of the buildable tx they are all transister qrp stuff, and need 3 stages to get 5 watts. I have studied radio since a kid, and itch to build some of the tube designs I studied.  I can build a one tube radio that puts out 10 watts very easily.  Now I know, dangerous high voltage, availabilty of high voltage capacitors and such favor solid state, but 10 watts and higher is much easier with tubes, and the cost is about the same.

see http://www.bga.com/~cfb/6LR8_CW_TX_Front.html

passed Tech on Aug 4, and on my way, cw is calling me!
Logged
WB2WIK
Member

Posts: 20545




Ignore
« Reply #6 on: August 06, 2001, 06:09:08 PM »

Congrats on passing the exam, and we're looking for you on CW.

Beware one-tube transmitters that put out 10W...although I think it's fun to use one, and fun to hear them on the air, it's almost impossible to make one sound good; reason is, changing in PA loading and plate current influence the oscillator stage and pull the frequency.  Most all "one tube" transmitters have a "chirp."  However, as I said, it is fun to hear them, and a chirp is not illegal!

73 & keep up the good work!

Steve WB2WIK/6
Logged
AUG4EXAM
Member

Posts: 16




Ignore
« Reply #7 on: August 07, 2001, 11:59:07 AM »

I need haven't been educated on this issue.  The one tube radios I have seen use a 6T9, or 6LR8, which are 2-in-1 tubes.  The 6T9 is a combined triode and pentode.  This is probably makes the chirp problem worse...being that the crystal controlled oscillator and amp are in the same tube. My hero silent key W1FB shows a qrp design that has a capacitor to shape the carrier to eliminate chirp.  I can see your point here, but I guess I remain undaunted because of nostalgic reasons.  
Logged
WB2WIK
Member

Posts: 20545




Ignore
« Reply #8 on: August 08, 2001, 02:55:53 PM »

Daunt away!  As I stated earlier, there's no law against having a chirp.

I have built many one-tube transmitters (not lately!) and every one was a very fun project...every one made contacts...and every one got donated to a local school or club, to help start new hams out in the wonderful world of radio.  Wouldn't trade those experiences for anything.

Having two effective tubes in a single bottle (envelope) makes no real difference, they still work like two tubes.  The PA stage will act as a bit of a buffer for the oscillator, and likely improve stability.  But if the two plates share the same power supply, the current drain of the PA stage will likely cause some voltage drop that will influence the oscillator, too.  How much, and what effect that will have, is unknown until you try it!  Homebrewing is great fun and I won't try to talk you out of it!

73 & hope to work you on CW,

Steve WB2WIK/6
Logged
AUG4EXAM
Member

Posts: 16




Ignore
« Reply #9 on: August 08, 2001, 09:39:31 PM »

I think the older tube days had a lot going for them as many people built their own gear.  Now trancievers have so many features that they rule the airwaves. I might be the wierdest ham around who wants to build my own simple tx. What woudl I do next? Add an am modulator! Very easy with a little elmer help. You can shout in my face about bandwidth and power advantages of ssb, and I might try that too, but I will be on the air with a big smile of satisfaction, in the am mode first.

I would be thrilled by having an off the wall kit with tubes in it, as long as I can learn something to help me on my next project. And tubes rule! I have an article from 1970, where there is a 200 watt linear amp with just one tube! Gotta love 'em.
Logged
Guest

« Reply #10 on: September 01, 2001, 03:48:47 AM »

Jim and Steve, have you two ever thought about starting a YahooGroup?  I think you two show up on every posting board on eham!  Yet, neither one of you is particularly prominent elsewhere on the net.  The way I figure it, given the number of hours you spend posting on eham, if you spend the same number of hours actually on the air, neither one of you has enough time left to support both family and job.  You're either retired, non-married, or socially dead!

OK, pulling the old tongue out of the cheek here...*thwock!* OK...

Hey Steve, cut the wet blanket garbage!!!  "Also, "new" circuit design based on tubes is nonexistent; thus, performance of a brand-new design for 2001 would be about the same as the older tube stuff from Collins, Drake, Heathkit, et al. 30 years ago. Where would improved performance come from? It cannot. "

Listen, dufus - haven't you been paying attention?  Part of today's bitching is specifically because today's solid state crap doesn't measure up to "old" tube designs.  If you're not familiar with Bob Sherwood's web site, where he has comparison figures for gobs of receivers, then you don't deserve to be making postings about receiver performance.  Like, that website's the end-all in comparisons.  Just go look at it (sherweng.com) - "where would the improved performance come from" what a stOOpid question!  Just duplicating the rigs of yesteryear would bring us back to where we were.

Now, let's say we take those lovely high-dynamic range input amplifiers (with those lovely tunable preselectors) and couple them with a twin-triode Gilbert Cell ultralinear mixer, and a modern-style linear-phase roofing filter, then one of the high-Q low-center freq filters that can be done because of today's improved components - voila!  Tubes, and performance even better than "back then".  But frankly, all they have to do is duplicate "back then" and they'd have me sold!  I've got a 756PRO sitting here right next to an R-4B.  While the 756PRO has lots of bells and whistles, and lots more flexible filtering than the old Drake, and even more sensitivity, it's the Drake that slugs it out in a crowded band without the front end keeling over from overload.  I mean, c'mon, Steve, don't you actually read test data?  How could you possibly have this concern?

Oh, yeah, another one of those blonde-defining moments in your fist post here - "it would take financing a transformer shop to
                  manufacture high-powered modulation transformers that haven't been made in decades... "  McSteve, anybody home?Huh  Duh, duh, duh....  I mean, c'mon again, dude!!!  In case you are completely ignorant of what's around you, TRANSFORMER SHOPS ARE MOSTLY FULL-CUSTOM HOUSES.  YOU TELL THEM WHAT TO BUILD AND THEY BUILD IT!!!  Have you ever heard of Peter Dahl?  He makes lovely multi-kW modulation transformers, and has for decades.  He was the original supplier of lots of the Collins and other commercial stuff, and HE NEVER WENT OUT OF BUSINESS!!!  And he's three times the price of anybody else.

Seriously, I've rebuilt a couple of commercial AM transmitters - I mean serious, 5kW plate-modulated affairs that are on the air continuously in AM broadcast service.  Getting a transformer shop to wind a modulation transformer is just ducky - they love that business!  A 5kW modulation transformer sets me back maybe $175.  For a ham-power-level transformer, that doesn't have to have the 15Hz response I demand for a commercial rig, I bet I could get them wound for $20 each in quantities of a dozen.

Capacitors are a no-brainer, too.  The same old brown 1kV silver mica caps are being produced at the same factory in India where they came from 40 years ago.  The brand names are even the same: Sangamo, Cornell-Dubilier, and so forth.  They're doing well, thank you.

Today's resistors are better than the carbon comps of yesterday, so I'd use them instead of seeking out the old drifty and noisy Allen-Bradleys of yore.

And I think coupling transformers wound with today's powdered iron would be better than yesterday's less-stable substances.

Frankly, the only components I worry about are the tubes themselves.  I haven't seen receiving type tubes made new in a while, except for those few numbers which find volume application in tube-type guitar amps.  Like the 7025 twin triode, a good sub for the old 12AX7 style tubes.

Yeah, the market is small.  And a tube type rig won't have the bells and whistles of a solid state rig.  But it will sound a hell of a lot better on the air, and the receiver will survive today's crowded bands better than the rigs that are built today.

No need to throw a wet blanket on this one.  Price them high; they're worth it because the basic performance is better.

Not so long ago, someone asked the 160 meter contest reflector "what's the very best receiver for 160 mters"?  The answer came back resoundingly: Drake R-4 series.  Why?  Because of the rig's ability to handle the wide dynamic range required on 160.  With all the nifty bells-and-whistles solid state rigs out there, it was a tube rig that won that question, hands down.

Awright, I'm done - back to real man's radio on 160 CW.

Dee (shaking his head at how clueless some of today's "experts" seem to be)
Logged
W2WDX
Member

Posts: 188




Ignore
« Reply #11 on: October 01, 2001, 02:46:59 PM »

Ya know...

People have been brainwashed to think performance is better with solid state. Not always so. It's just less expensive to manufacture, easier to design and construct power supplies, and makes things smaller.

Performance is not always better, and in many applications performance is noticably poorer.

One big disadvantage is the newer digital transceivers are impossible for the majority of hams to repair themselves.

Tubes .... yeah baby!
Logged

W5HTW
Member

Posts: 729


WWW

Ignore
« Reply #12 on: October 02, 2001, 11:13:52 PM »


Well, some say that tubes are just a "purist" attitude.  But in audio, anyone who can't tell the difference between a 100 watt Fender amp and a 100 watt Kustom solid state shouldn't touch a guitar.  That's why the audio folks like tubes.  Not so much the specifications, but just the way they "sound, baby, the sound."   And they keep you warm on a cold stage.  

Ham gear, though, is a different matter.  Despite growing up on tubes, and even being a ham before the darned transistor was invented, I really doubt new tube stuff could do more than be a hobby for someone with deep pockets.  Oh, but would it be fun!  

One problem though, is people don't want to "tune up that rig."  They want instant band changing, flip the DSP and work the DX/contest/county/whatever, and move on.  All bands, muy pronto.  So such a venture (dream that it is) would have to appeal to the purist who either WAS in it the way it was, or wants to pretend to be.  Like building a replica of an MG-TC sports car.  It looks like a duck, it walks a bit like a duck, and it may even quack a little, but it lacks that greasy smell of petrol, and the quick-access tool kit so you can pull over and adjust the carbs every 100 miles.   There ain't no crankhole  up front, beneath the radiator, and no crank folded beneath the seat.  People don't want that smell, folks, not the majority of them, which is why they drive a Lexxus or Saturn.  Or a 1990 Escort.  

It's a fun thought, but it will never get out of the basement,  let alone off the ground.  You can't go back and build a Collins S-Line, (Eldico tried back then and missed the boat) or a Halliscratchers SR2000 (or, Lord of Lordes, a Cosmophone!) and put all the new stuff in it cause when you're done you've got an MG-TC with an EFI, and Detroit auto transmission.   Kind of like a kerosene lamp that generates its own kerosene from a portable, pocket-sized plutonium-discharge Kerosene-Cracker.  Tain't an antique, tain't the future.  Tain't real.  And probably tain't fair.  

I like tuning the preselector, peaking the grid, dipping the plate, loading the final.  The operative word is 'operating.'   But I'm in a minority; most folks want to Plug and Play, PTT "right now Jack", and connect the Pentium X 4500 and let the computer do the walking/talking.  It WAS ham radio.  It ain't thataway no more, hardly ever, again.  

So let us tube types dig through the trash bins for the old National NCX5 only used by the little old lady on Sweepstakes, and stashed in the garage the rest of the year.  And all she wants is 25 bucks and she'll throw in the tower in the back yard.  

There's an expression:   You can't go back.  

I like it like that.  Been there, done that, still doing that.   Now if we want to build a brand new 50 Ford Custom flat head V8 with 3-speed overdrive, like my teen girlie machine, I'd take a closer look.  But why mess up the fun of some old man like me who is, as someone suggested, using the rig today I couldn't afford back then, by making them a Gigabuck a dozen and available to all?  

But, darn it, they sure do glow nicely in the dark!

73
Ed W5HTW
Logged
W7AX
Member

Posts: 1


WWW

Ignore
« Reply #13 on: October 09, 2001, 01:09:32 AM »

This may not be the best idea right now or ever but it does bring back great memories.  As far as solid state being the dominator, I wouldn't be too sure of that. In regards to amateur radio possibly but I think BC stations still for the majority run tubes. It's still more economical to run tube finals than to buy one of the newer breed of solid state amps. At least commercially. Solid state amps these days for amateur service are actually comparatively cheap to build. In part due to the high cost of the larger and higher voltage transformers needed for tubes not to mention safety. But homebrewing may be back in vogue and nothing wrong with a nice CW and/or AM tube type rig. I probably can even come up with all the parts for 'ya ! Best wishes es 73.... de W7AX
Logged
W9GB
Member

Posts: 2600




Ignore
« Reply #14 on: October 14, 2001, 12:34:45 PM »


I believe that you would have more success in provdinfg specific parts or services for restoration of current radios on the market.  Surplus Sales of Nebraska started with the Collins surplus parts they acquired over 15 years ago, and provided a service to the Collins market.

The R390A is a great example of a true boat anchor receiver with support.  (gov't was curching these by the hundreds a few years ago)

http://www.avslvb.com/R390A/index.html

Some ideas:

Good Knobs (a weighed knob for the Heathkit SB series or Collins S-line) are always in demand for restorers or homebrew - especially the HeathKit gear.

Hard to find parts (sometimes this is just a matter of placing a qty order large enough to current mfg.).  Peter Dahl does a good job for the transformer market

Bend metal:  Provide a punched metal/silk screen chassis for a popular design or popular older QST article.  Hammond still has some great boxes (this is a service currently provided to the audiophile market, Dynaco etc.).  I no longer have my Greenlee metal punches and reamers .. and would save me a great deal of time (and have a nice looking project in the end).  Nearly impossible to fit a machine shop that will take time for the hobbyist anymore.

Semi-kits to update older products.  Power supply and tube updates have been most popular (new power supply/regulation boards for amplifiers and transceivers ... i.e. Drake Shop, Detron amplifiers, SB amplifier updates)

Painting/Powder coating:
Professional repainting and/or powder coating of radio chassis always in demand.  Many amatuer now live in urban areas and no longer have access to garages or areas where proper painting/ventilation can be accomplished.  Color matching and quality is paramount.

Quality plating:
Always looking for quality nickel or chrome plating in restorations (i.e. Vibroplex bugs).  While many shops cater to the automotive or motocycle restoration business, many do not have the quality for small parts or radio work (Ask Bencher how long it took them to find a quality chrome plater for there paddles!)

Licensing:
The "meatball" and "Winged" logis on S-Line equipment does come up missing or needed for a proper restoration.  While legal issues would likely have to be addressed, Antique Radio does supply these restored items for the vintage 1920's and 1930's restroation market.
Logged
Pages: [1] 2 Next   Go Up
  Print  
 
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.11 | SMF © 2006-2009, Simple Machines LLC Valid XHTML 1.0! Valid CSS!