- July 14, 2017 at 4:09 pm #9405
Jordan DobrikinForum Participant
Welcome, Jordan Dobrikin
Semiconductor replacement of tubes in Antique pre 1930’s radios
Tagged: Antique Tube Radios, Steampunk, Transistorize
July 14, 2017 at 4:02 pm
Looking for comment, advice, assistance retrofitting transistorizing pre 1930’s Tube Radios to lower safer voltages
Are these suitable
RF Amplifier PC Board 2N5109 PC Board or Kit
DC 12V 10KHz-1GHz 10dBm RF Broadband Low Noise Amplifier LNA Module HF VHF UHF
AntiqueRadio Tube Replacment/Substituion
I am seeking help, advice assistance and comment on replacing ALL the Tubes in Antique Radios with Transistor/Semiconductors that will operate at lower, safer voltages.
The main target is the RF Stages of TRF Radios and to a lesser extent Regenerative Receivers.
Detection and Audio will be handled by a simple Detector (Crystal) and Audio Amplifiers on a small PC Board readily available on Ebay.
I want to explore the idea of using Radios on a Chip and receiver PC Boards using “Radio on a Chip” chips. Picking up the RF at the input to the detector/audio amplifier and shunting off theunused audio to ground
TRF radios with 2, 3, & 4 Tuned RF Stages; like the Atwater Kent Models 20C and 30
Regenerative Receivers Radiola III, Radiola IIIA and Westinghouse RADA
73 de Jordan ve7jjd
STEAMPUNK Radios/Receivers: Crystal TRF & Regenerative
Objet d’art Plural Objets d’art
Radios: Building Crystal TRF and Regenerative Radios using Antique/Vintage Components, along with modern electronics and components (Transistors, Semiconductors, Radios on a Chip, Op Amps) to come up with Objets d’art Sculptures that are also highly functional Radios.
(Variometers, Variocouplers, Cats Whiskers, Variable Condenser/Coil Assemblies, Vernier Dials)
Receiverstransistorize: Retrofitting Antique Receivers/Radios, Crystal, TRF and Regenerative to operate sans Cabinetry at safe, low voltages. Both Hollow-state and/or Solid-state.
Atwater Kent Model 20C (original tubes: UX 201A & UX 200A)
Radiola III (original tubes: WD 11; UX 199; UX 120)
Radiola IIIA (original tubes WD11; UX 199, UX 120)
Westinghouse RADA (original tubes UV 200, UV 201, WR 21)
Metrodyne Super FiveJuly 18, 2017 at 12:46 pm #9425
Hi Jordan – sounds like you are mainly interested in solid-state replacements for 01A tubes as used in the AK 20C and AK30, and for WD11 tubes as used in the Radiolas. A popular replacement for the 01A is a circuit using a small light bulb and a photoresistor with an FET, with a detailed discussion here:
One point noted in the ARF thread is that you might expect to have to do some tweaking of each stage in a TRF to get it to work properly with all SS replacements.
For WD11 replacements in my Radiolas, I have recently fabricated substitutes using miniature 5676 tubes inside cut-off test tubes attached to custom bases, and hopefully will publish the construction details in a future issue of the CVRS Newsletter. I haven’t found an FET circuit to substitute for the WD11 so have taken it as a challenge to come up with one for the Newsletter at the same time.
In general, the SS replacements I’ve tried work quite well. The solid-state 1L6s in my TransOceanics give better performance than the original tubes.
You also mention trying ‘Radios on a Chip’. Not sure how you will get at the input to the detector inside the IC package, but the venerable MK484 chip (now TA7642) is available on eBay at 10 for a US dollar (with free shipping!).
GaryJuly 19, 2017 at 9:00 am #9426
Hi Jordan – here are the links from my last post:
GarySeptember 25, 2017 at 11:19 am #9578
This topic puzzles me about solid state replacements? Are these tubes unreliable or are they assumed to be hard to get? A fleaPay search revealed many for sale and yes the price varies but one seller has 80 of them all testing as good for $12.99 or best offer each. They also vary in ballon style or shoulder top throughout my search. Who knows I probably even have some in some of my battery radios or hoard. The only solid state conversion I’m pondering is for vibrators but they are hard to find in Saskatchewan and if you find them they are used or NOS mechanical.September 29, 2017 at 11:43 am #9583
Hi Don – I agree, O1As are plentiful and quite cheap. The problem used to be with 1L6s when their price went crazy to over $100 each some years ago, but prices have come down and today NOS 1L6s are being offered at about the same price as a solid-state replacement (~US$40).
I mentioned WD11 replacements earlier because these tube are fragile, and hence quite valuable in working condition (>$100). Adapters to other tubes are available for about $25 each (without the new tube), and a complete replacement can be fabricated using a 5676 tube for about $15.
GarySeptember 29, 2017 at 12:35 pm #9586
Yes I guess so but given that kind of defeats the purpose of restoring these fine examples and for the same price or even higher I would stick a balloon or shoulder top in them (unless I just could no longer find them ) but here is a good example of how I look at this. Take my 1950 Mercury Sport Sedan as an example. I was told it was extremely rare and I said to a point but….. Then the fellow said NO yours is extremely rare because it is totally stock and only a handful of them are still very stock and restored to original and not totally mollested!! I was at a gas station a number of years ago straight off the highway and I let the engine idle for a minute or two and a fellow probably in his 70’s to 80’s walked by the grill and heard something under the hood idling whisper quiet barely audible and said “I bet you have a Chevy small block under the hood” and my comment was most certainly not! It would be too unreliable! That got quite a laugh out of him as he nodded his head. Getting a schematic from Don enabled me to get the radio working properly and it makes me laugh when my friends think the radio doesn’t work and they are puzzled when I say let the tubes warm up. Yesterday I bust my ass dragging my Heathkit Marauder transmitter out of storage at one of my houses that I’m slowly rebuilding. It is from probably 1957-59 and weighs probably 85 plus pounds iand guesstimating 2 feet long, over a foot wide and almost a foot tall and I have a solid state transiever that does the same but I can carry it with one hand very easily. Someday I will purchase a matching receiver (just as big) and get a working matching set going. Oh yes one of these days I will look for a “two or three dialer” or knobs and a horn and get it functioning but yes I was warned the tubes are usually worth more than the receiver but this is part of the challenge just like my Mercury. Stock parts are scary and miserable to find and it is just like what you see on the TV series Cuban Chrome but I was in my mid twenties when I bought it and now I’m 56 so obviously I find ways to get around this situation.September 29, 2017 at 12:41 pm #9587
This forum doesn’t like my iPhone 5C. The resolution is too high so I guess I will have to dig out my 4S to reduce the upload error message. SighSeptember 29, 2017 at 2:21 pm #9588
Right on, Don. Vintage tubes can often be worth more than the value of a radio, particularly before the radio is restored. I have original, working, WD11 tubes for my restored Radiolas, and leave them in the radios for display, but exchange them for fabricated replacement tubes when I want to demonstrate how these old regenerative sets work. Like many of us, I enjoy the challenge of completing a restoration that is indistinguishable from the factory original.
All the best getting the HX-10 back into shape. Do you have a Mohawk receiver to go with it?
And what is the error message you get when using your iPhone 5 on this site? We tried to design the site to work with all smartphones (I see the Forum ok on my iPhone 6s.)
GarySeptember 29, 2017 at 3:06 pm #9594
The file is too big by a smiggen and by that 1/4-1/2 a Meg above 2 meg limit. In other words half of the square root of bugger all.
The HR10 or Marauder probably works but I would need an antenna or dummy load to test it. There is probably one in all the boxes of ham gear but never looked for it yet. Otherwise it is in mint condition with the exception of a small chip in the paint on top and one rubber foot missing. At least it is SSB and not Am. My father had an Apachi complete with the SSB adaptor from Heath with a working matching Mohawk but he sold them not knowing I would have bought the Mohawk. I left the HR 10 with him to test but his health went down hill very fast and became a silent key and this is how I ended up with all of his newer SB series (SB101) and all matching accessories including his Heathkit linear amp of the same vintage, scope, etc. etc. and a Hammarlund in very fine condition. The Linear amp still runs on 10 meters so I could warm up some CB’s with 2000+ watts if I wanted if anybody still uses them. He had it on 110 volts instead of 220 and the lights always flickered especially while using the key. At least I got a pile of tubes for everything which is good plus what I hoarded before I inherited his. Who knows that was 30 years ago when he sold the Mohawk and Apachi and probably didn’t get much for the pair back then and they probably sell for more now. I sold weigh my HR 10 and hopefully the bathroom scale doesn’t bust when I stand on it holding this boxcar. 85 is a good guess perhaps more or less depending on how I feel.September 30, 2017 at 11:07 am #9602
Off topic from the original post, sorry This HX-10 is quite interesting compared to the Apache and from what sources claim are much more rarer than the Apache which is slightly older and as a result they are usually paired with the Mohawk which was the match of the Apache. I find it comical that they state the Marauder was lighter than the Apache and this is probably misinformation because they are very close in vintage and the Apache was only AM whereas the Marauder is SSB with. AM being possible with a twist of a selector to AM mode. If anyrhing it would be the same or pound or two heavier. No comes the task of finding out what receiver was of the same vintage other than the slightly older Mohawk. I could see the Apache being heavier if you had the outboard SSB converter perched ontop or beside. They weren’t that small remembering what that accesory looked like.September 30, 2017 at 11:23 am #9603
Oh how comical on another forum pertaining to vintage Ham equipment where one fellow referred to these as “The big green Indian sets” and indicated there wasn’t really a match that came out at the same time for the receiver other than the Mohawk and a HA-10 Warrior linear amplifier. This is what his big green Indian set of a Marauder, Mohawk and Warrior consisted of. His collection looked like the inside of a Heathkit store with all of the big green Indian sets all set up in his massive shelf. It would have to be built like a brick outhouse to support this weight.
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