Forums :: NEW! Web Resources :: Features :: Photo Gallery :: Vintage Radio Shows :: Archives
Support This Site: Contributors :: Advertise


It is currently Sep Mon 28, 2020 6:09 am


All times are UTC [ DST ]





Post New Topic Post Reply  [ 12 posts ] 
Author Message
 Post subject: RCA Acorn Tube 9004
PostPosted: Sep Sat 14, 2019 3:47 am 
Member

Joined: Jan Mon 17, 2011 2:10 am
Posts: 223
Location: Revere,Massachusetts U.S.A.
Hi Folks, I have several of these RCA Tubes and I understand that they are useful in the U.H.F. world of old, from what I have read mostly used at the beginning of WW2.
I would like to build a UHF receiver using the 9004 and other acorn tubes, is there anyone out there that would know of a circuit that I could use ??

Thank You
Tony

_________________
I Love The Warm Smell Of Tubes In The Morning


Top
 Profile  
 
 Post subject: Re: RCA Acorn Tube 9004
PostPosted: Sep Sat 14, 2019 6:25 am 
Member

Joined: Jan Thu 01, 1970 1:00 am
Posts: 3594
Location: Seattle WA US
You can find examples of radios using the acorn tubes in the manuals for Hallicrafters S-27, S-36 and S-37.

Suggest you try to find acorn sockets before spending much on this project.
Good luck,

-Chuck K7MCG


Top
 Profile  
 
 Post subject: Re: RCA Acorn Tube 9004
PostPosted: Sep Sat 14, 2019 7:32 am 
Member

Joined: Jan Mon 17, 2011 2:10 am
Posts: 223
Location: Revere,Massachusetts U.S.A.
Thank you, I know that there are a couple in my junk box

_________________
I Love The Warm Smell Of Tubes In The Morning


Top
 Profile  
 
 Post subject: Re: RCA Acorn Tube 9004
PostPosted: Sep Sat 14, 2019 7:54 am 
Member
User avatar

Joined: Sep Mon 16, 2013 2:42 am
Posts: 4185
Location: Tucson, Arizona U.S.A.
There are articles for home construction of receivers using acorn tubes tin the ARRL handbooks and QST from the late '30s and early '40s. You will probably find types 954, 955, and 956 the most useful unless you want it to run on built-in batteries.

_________________
Jim Mueller


Top
 Profile  
 
 Post subject: Re: RCA Acorn Tube 9004
PostPosted: Sep Sat 14, 2019 1:13 pm 
Member

Joined: Jan Thu 01, 1970 1:00 am
Posts: 1014
Location: St. Louis, MO, USA
Many years ago, I built a 1-tube battery radio using a single acorn tube and 3-9V batterys for the plate voltage. It worked about as well as a radio made from miniature battery tubes.

Dennis


Top
 Profile  
 
 Post subject: Re: RCA Acorn Tube 9004
PostPosted: Sep Sat 14, 2019 3:55 pm 
Member
User avatar

Joined: Jan Thu 01, 1970 1:00 am
Posts: 14745
Location: S. Dartmouth MA 02748-1225 USA
Sending a PM on an Acorn radio...

Chas

_________________
List' & I will Enchant Thine Ear


Top
 Profile  
 
 Post subject: Re: RCA Acorn Tube 9004
PostPosted: Sep Sat 14, 2019 4:04 pm 
Member

Joined: May Thu 14, 2015 4:15 pm
Posts: 2475
Location: Dallas, TX
I have a few acorn tubes. I have read that the socket design can lead to problems. Inserting the tubes puts side force on the pins and can lead to the glass to pin seal leaking. I don't have any sockets and have thought if I did want to use them I would rig up something with pin sockets on short wires that would slide on the pins. You aren't going to be changing tubes that often.

_________________
Tim
It's not the Destination, It's the Journey.


Top
 Profile  
 
 Post subject: Re: RCA Acorn Tube 9004
PostPosted: Sep Sat 14, 2019 6:01 pm 
Moderator

Joined: Jan Thu 01, 1970 1:00 am
Posts: 30654
Location: Livermore, CA
Unlike miniature tubes acorn pins will accept solder. Instead of a socket you could solder directly to tube pins. Don't keep the iron on pins very long.

_________________
Norm


Top
 Profile  
 
 Post subject: Re: RCA Acorn Tube 9004
PostPosted: Sep Sun 15, 2019 3:25 am 
Member
User avatar

Joined: Jan Mon 18, 2010 2:13 am
Posts: 21116
Location: Dayton Ohio
The 9004 is nothing but a diode. Not much you can do with it.

As for acorn sockets, they show up regularly.

https://www.ebay.com/itm/392401283987

I see them quite often at hamfests too.

-Steve

_________________
Radio Interests
-Zenith
-Sparton
-Pre-War FM
Consoles and floor models, the bigger, the better!


Top
 Profile  
 
 Post subject: Re: RCA Acorn Tube 9004
PostPosted: Sep Sun 15, 2019 6:44 pm 
Member
User avatar

Joined: Jun Wed 08, 2011 2:33 am
Posts: 10816
Location: Ohio 45177
I hoarded some of the sockets that I found at a small hamfest a few years ago but have not used any yet. I too am hard pressed to find much use for them. I had a URM-something generator that used one. And when I was young I had a surplus tunable VHF receiver that used them. I have seen old references to using the acorn diode as the rectifier in an RF probe. Rather bulky I would say but it would not blow out like a crystal diode from too much RF. The sockets were ceramic but some were made of "low loss" polystyrene too. Careless soldering would surely wreck those. There are some old plans for simple superregen receivers using those tubes but that would be pretty useless nowadays, too. They are not much more than a novelty now. Thus sell cheap. I have not seen any of the early round top ones that came out in the mid 30s. Some audio person should design a tube preamp using them and then they would start to sell better. IT would seem exotic and esoteric like some of the other oddball tubes used.

_________________
Reddy Kilowatt says; You smell smoke? Sorry about that!


Top
 Profile  
 
 Post subject: Re: RCA Acorn Tube 9004
PostPosted: Sep Mon 16, 2019 3:12 am 
Member

Joined: Mar Wed 16, 2011 10:44 pm
Posts: 1396
Location: Peekskill, NY
Fun project - a regen receiver from an acorn tube, built in a cigar box.

Image


Top
 Profile  
 
 Post subject: Re: RCA Acorn Tube 9004
PostPosted: Sep Mon 16, 2019 3:11 pm 
Member
User avatar

Joined: Jun Wed 08, 2011 2:33 am
Posts: 10816
Location: Ohio 45177
In the late 30s they were best way for hams to get good results in VHF(called UHF then) frequencies like 112 MHz or somewhat higher. Then heavily used in WW2 by the military, thus, the tons of surplus tubes for cheap. Outside of that, the only commercial uses I can recall were for factory made ham VHF rigs, maybe. Postwar, the more practical miniature tubes ate into their applications to the point that they became rarely used. Except for specialized purposes, like the oscillator in my long gone URM signal generator.

_________________
Reddy Kilowatt says; You smell smoke? Sorry about that!


Top
 Profile  
 
Post New Topic Post Reply  [ 12 posts ] 

All times are UTC [ DST ]


Who is online

Users browsing this forum: No registered users and 9 guests



Search for:
Jump to:  


































-->


Privacy Policy :: Powered by phpBB