Feb 161999


BC-348 FAQ

by Buzz Harrah, KE0MS
February 15, 1999
Originally posted to the MilSurplus Mailing List
Reprinted with permission


Calling all MIL-itants,

Recently you all came to my rescue when I needed “Fatherly” advice on a BC-348 I’d found. Thanks to your info, I’ve worked a deal with only pickup yet to take place. Your pricing information especially helped the deal “gel”.

I was asked by several thru direct mail if I could gather together my info and publish it for all the other BC-348 “wannabe owners” out there, kind of as an FAQ or something. I got almost 2-dozen responses over the weekend to send it, so, (not knowing how many are on this list) I decided it’s easier to let you all get it and judge for yourself if you need it. Delete it if you don’t.

All of this info was contributed by YOU who responded, the members of this list. You may recognize some of your comments. I moved them around to most logically answer the questions posed in the FAQ I came up with.

However, this info is presented to you AS IT WAS PRESENTED TO ME. I could not/did not attempt to verify every fact I received. (How could I?) And, you all know the “BA-Mantra”, imported from another source: “YOUR MILEAGE MAY VARY.”

As we all have a perspective, I included all the pertinent data I got and grouped in into the general categories you will see.

Enjoy. I did reading it as well as cutting and pasting it again. And save it; as I think it’s a good BC-348 primer.




  • The BC-348 was the main HF receiver in US Airforce bomber aircraft in WW2, in conjunction with the BC-375 and ART-13 transmitters. The original design was the BC-224 (US Army Signal Corps) and the BC-348 was the adaptation for the requirements of the Army Airforce. The receiver as issued, runs on 24VDC (the standard DC voltage on aircraft) and generates the required plate voltage (around 250VDC) with a dynamotor which is inside the receiver.


  • The BC-348 was my first “real” HF receiver in 1964 when I first got my ham license and worked about 100 countries with it. Now I have 2 of them, with an ART-13 transmitter, to functionally duplicate the B-17/24/26 type bomber radio compartment and I use that station quite often, mainly on the East Coast military collectors’ net on 75 M.
  • These are pretty fair radios for AM and CW use. Not real selective, but they do have a xtal filter and with an added Q-Multiplier, they do nicely.
  • Be prepared to replace every coupling/bypass cap. Not a hard job as most are visible and usually strung between two posts on a phenolic board. The filter caps may need help also as will some of the resistors. I did a complete cap changeout and found only 3-4 resistors out of tolerance. The whole job took a few hours, but she played nicely when I finished.
  • There were many other modification articles and books out regarding the BC-348, so you can expect the receiver might have some or all. One of mine was completely rewired by a previous owner, redone top to bottom, and equipped with an AC power supply. Oh, yes it is also painted bright shiny lime-green with gold Dymo labels. It worked quite well, and after awhile the looks grew on you (like a fungus?) so I never changed it. The other one is more original.
  • The BC-348 is a great receiver, a little broad in the selectivity department, but a neat way to cruise the bands! My first exposure to shortwave came from a BC-348 so the radio has a little sentimental value to me.
  • My reason for knowing is that I had an unrestored one in High School (a loooong time ago). It still had the dynamotor.
  • Ah, the BC-348! One of my first military BA’s. Used as a liason receiver in B-17’s and some other aircraft. We gave our boys good stuff.
  • Single largest problem with all the radios of this vintage is paper capacitors. The ‘348 O uses about 18 or so of them and they’re all subject to failure. Normal procedure is to replace them all, check tubes, etc. and an alignment. If the radio has seen regular use, vs. sitting for years they seem to last much better.



Q: OK. This had one of those nasty DYMO label-maker-sticker-tapes saying “117V WIRING.” It plugged directly into the wall. Was this unit usuable for different voltages with a tapped xfmr arrangement, or had he modified his do you think?

  • The BC-348 was primarely an aircraft receiver with the dynamotor as the only INTERNAL power supply. There were external rack mount 110 vac supplies available in the military to run the radio on the ground. This is probably a homemade conversion.
  • When these receivers got to the surplus market, the first things hams did, was to yank out the dynamotor and build a small power supply that mounted where the dynamotor used to sit, for 115VAC to supply the filament and plate voltages to the receiver.
  • BC348s were aircraft receivers and used a dynamotor for the high voltage generation. He modified it by removing the dynamotor and replacing it with a power supply.
  • Sounds like the BC348 has been modified enough to allow for a built-in power supply. This was common practice when these things came out on surplus market.
  • I do know there were some mods that allowed 110 volts, but most radios were just changed by removing the dynomotor and installing a small power supply. I have not put a 110 supply in mine because there is no way I can see to get the 110v into the case with out some type of hole or rewiring the power plug, so for now I run it off the dynomotor and it is a nice little radio with plenty of volume, but the dynomotor is a little loud. I guess that wasn’t a problem with 4 1200 HP engines running.
  • The “117 wiring” label you noticed probably indicates that someone modified the unit to have a 117-volt AC power supply inside. The original BC-348s used a dynamotor to convert low-voltage DC (28v, 3a for DM-28 dynamotor typically found) to the voltages needed by the receiver. The open space intended for the dynamotor is a good place to build an AC supply and many hams did so.
  • Lots of them around, and there was a 117 volt model, but most were modidifed to run on 110 by hams – they took out the dynamotor.
  • Second, all BC-348s were bought by the military as 28 volt aircraft radios, there were no military versions that operated on AC. There was a 12 variant called the BC-224(actually as its number implies, the 12 volt version came first, the 348 was the 28 volt version, but a heck of a lot more of the 348 were built). All the AC conversions you run into are most likely to be done after they were released from military service. Note that a lot of the 348 were bought by the airlines right after the second world war, so some of the conversions were probably very professional looking, most of the ham conversions that I have seen were very sloppy.
  • There is a rumor, but no hard evidence that I have seen, that Hallicrafters specifically made a drop in AC supply that replaced the dynamotor, this would be easy to do mechanically-it would just be a screwdriver operation, but if this is true there may be a concern that one side of the AC line would be tied to the chassis-a definite safety concern.
  • The AC supply was a common mod and there were many variations. They were normally built onto the same chassis that the dynomotor was mounted on. If you can get the original mount bracket with shock mounts, that is a real plus.
  • I have a BC-348Q that is in great shape. Still has the dynamoter in it, and the ac supply is very neatly tucked up underneath it.
  • Normally they were 28VDC with a dynamotor. You can bet it was modified.



Q: The rig had a approx. 2″ x 6″ panel screwed on the right side, centered, covering what may have been some sort of — what? Was there a knockout on these rigs that allowed adding something?

  • This pannel is standard equipment on the BC-348. It provides access to the underside of some of the tube sockets. They ALL have them.
  • The panel you describe allows one to reach the tube sockets and some capacitors. Designed to look “plain” with 6 screws holding it down.
  • I have a BC-348Q and it is complete from the box(no mods) the 2X4 panel is to get at the tube bases for alignment, checking etc.
  • The plate you mentioned is original, it is just an access plate to allow service on components in that area. Once you dig into the radio, you will see why they put it there. It was also a good place for hams to mount extra pots and switches.
  • This is quite a nice receiver when working properly. The plate you mentioned on the right side of front panel is used to cover the socket connections for several of the tubes. The chassis is an aluminum CASTING, neat stuff for 1943!
  • That plate on the front panel is supposed to be there and allows access to the bottom of the tube sockets mounted along the front panel.
  • It allowed access to the RF and Mixer stage components under the tube sockets.



Q: Were there several variants of this rig? This one went .1-.4 MCs, Then went from 2- about 20 MCs if I remember right. Skipped the BC band.

  • BC-348 Receiver, 200-500kHz and 1.5-18mHz, six bands, AM/CW, crystal filter, 915 kHz IF, BFO, MVC/AVC, 28v, 3a for DM-28 dynamotor, 10.5″x18″x9.5″, 44lbs, variants:
    Model Manufacturer Tube line-up
    E RCA 41, 6B8, 6C5, 6F7, 6K7 (3)
    H Belmont Radio 6B8G, 6C5, 6F7, 6J7 6K6GT, 6K7 (3)
    J Wells-Gardner 6SR7, 6K6GT, 6SA7, 6SJ7, 6SK7WA (4)
    K Belmont Radio same as H
    L Belmont Radio same as H
    M Stromberg-Carlson same as E
    N Wells-Gardner same as J
    O RCA same as E
    P RCA same as E
    Q Wells-Gardner same as J
    R Belmont Radio same as H
    S RCA same as E

    [different mfrs got their own variant letters as they sometimes used different tubes and had different wiring schemes.]

  • Yes, there were some variants, frequency wise, but the one you describe is standard. (Seems that they ALL covered basically the same bands, but variants involved manufacturer differences, or layout differences BECAUSE of different manufacturers. The bands they covered (by my info) seems to tell me they ALL skipped the BC band.)
  • The letters (L, Q, S to name a few) in the variants, to keep it short, denote some tube differences (for example some models use 12K7 for the RF amp while others use the 12SK7, etc.) The performance is the same for all models. They all had the VLF band, for picking up Navy distress signals.
  • They came in several models, but are all basically the same circuit wise. Mine is a BC348R and is one of the older models. Uses double ended tubes. The newer models use single ended tubes. The 348Q is one of the newer ones and is seen often for sale.
  • They do skip the BC band. Guess the AAF didn’t want the pilots listening to the radio while attacking Jerry……..
  • To answer your questions though, the frequency range is .2 to .5 and 1.5 to 18 mc/s, although a very few of the early ones did not have the .2 to .5 band on them. There were a few ham conversions that rewound the low freq range for 10 meters or the broadcast band, but these are all ham conversions, not done by the military.
  • there were two major versions of the 348. Externally they were interchangeable, operated the same, covered the same frequencies, etc. The J, N, and Q series were made by Wells Gardner and were built differently internally than the others, a different tube lineup and some mechanical differences, plus a different arrangement for the CW OSC on off switch on the front panel.
  • Apparently the ID tag is still in place, and that will tell you what series the ‘348 is…..there were many variations with different suffix’s. Mine is an O, which was made by RCA. The series suffix is important because the circuits were different as was the tubes used. Some models were very similar and some were markedly different.
  • The Broadcast band is skipped in all of them I think.
  • Several models but they all covered the same freq range as you stated.
  • Did find a Schematic in the old CQ Surplus Manual – but there wasn’t anything else in the mag just a Schematic. I did get a TUBE line-up though.BC-348-R
    .1-.4 MCs
    .950 -> 18 MCs (915 KC IF)

    1st RF VT-117
    2nd RF VT-117
    1st Det/Osc VT-150
    2nd Det/avc/CW osc VT-233
    1st IF VT-117
    2nd IF VT-117
    3rd IF VT-116
    Audio VT-152



Editor’s note: My unit described as “kinda dirty”, but should clean up ok; but no obvious mods other than 117VAC mod. The 117VAC modification was the “ONLY” MOD that seemed to not significantly detract from the desirability of buying one of these units. While the original DYNAMOTOR was preferred by the masses, this mod is so common that it was felt (or at least I detected) that getting one that HADN’T been modded in this way was highly unlikely and should NOT be cause to pass a unit by.

Also, any comments relating to EBAY are indications of PRICING PHENOMENON in today’s market ONLY, and do not constitute an endorsement of EBAY selling or indicate that EBAY sold-equipment is better. It simply indicates that more is paid for these rigs on EBAY than at the normal hamfest-type outlets available.

Q: What is one of these things worth? (ballpark estimates are fine.)

  • I got one of these beauties (BC-348-R) and it was converted to AC and works very well/ Going prices range from $80 to $200 depending on condition, etc.
  • Typically bring $70 to $150 at swap meets, depending on condition, but sometimes up to $200+ on the Ebay internet auction site.
  • I paid $45 for mine. Seen them on e-bay for up to $150. A modified one in fair condition should be about $35-50. A pure, unmodified, original condition one with dynamotor might go for $175 or so and in my estimation would be worth it.
  • The case should have no other holes, just the cut out for the 8 pin power-audio plug. There are several sites that have the manual on-line. As for price I would say $150-200. E-bay has changed the price of things lately. I paid $100 for mine about a year ago.
  • Value – anywhere up to $140.00 depending on condition. Most go for $50 – $75.00 at flea markets, $75.00 up on the internet.
  • As far as price, the typical price I have seen for a ham modified unit with no added holes on the panel, an AC supply and missing the shock mount and connector that mounts on the shock mount, is about $75. Less than that for added S meters, front panel switches and other mods, more if it has the shock mount, connector and original dynamotor. I would say that a military original complete unit would be about 150, but I haven’t actually seen one of these offered for sale so that’s just a guess.
  • The BC 348’s go – depending on condition and the owner’s willingness to part with them – for anywhere between $50 for a heavily modified or good parts unit to $150 for a very good, unmodified radio. It may be even a tad more if the receiver is mint, as issued and has the original dynamotor in it. The dynamotors are scarce and sometimes cost almost as much as the radio itself. I personally paid $100 for each of my BC-348’s, with homebrew AC supplies in them (good workmanship, however) and good cosmetic shape, in working condition.
  • $50.00 to $100.00. Sounds tike your find would be on the low end.
  • I have seen them (348s) occasionaly for sale, and I think that Fair radio had some a few years ago. I seem to remember they were around $100. Could be wrong, but I think thats right.



Q: Can anybody help me with specific info, advice to persue or evade, etc?

  • GET IT………. you’ll love it and you’ll have a piece of history.
  • They are OK radios, but modern radios are MUCH better. On the other hand if you are a tube nut, then they are a must have along with an R390A.
  • Just remember that SSB was not in use when they were used, that came later. Even the R390A receiver did not support SSB.
  • If you like old tube collectables, then it might be right for you.
  • I have a BC-348Q that is in great shape.
  • All in all a neat radio.
  • I’ve had several over the years and always enjoyed modifying, using, and abusing them.
  • I got mine for repairing a BC radio for a friend, cost me a resistor, two 40 UF 450 volt caps, and two diodes. Had to solid state an old Circa 1930s radio. The rectifier tube had a burnt out filiment. No possible spares. I was given the BC-348 even thought I didn’t really want it at the time. Now I wouldn’t mind having it here [while away from home].
  • It is a lot lighter than my R-390A!
  • Looks like I will be able to buy 2 BC-348s this weekend. Matching transmitter too. There are Antenna tuning units too.

Editor’s note: I got almost nothing on Antenna tuning units, other than it is believed there are several, as part of the “Liason Sets”, using the ART-13 transmitter, of which this unit is part.



Editor’s note: About 1/4 of the replies I got tell me I should GRAB the TEST SETS, or GRAB THEM and sell them to THEM! You guys must like these ARC-5s things, too.

And here’s what some said about the ARC-5s (relevant to the BC-348):

Q: The now SK had an OS-8B scope, URM-25D sig generator, a mil audio generator (I can’t remember make or model right now) and… the BC-348. He also had some ARC-5 stuff, including a BC Band one. But, I have some questions about the BC-348:

  • As to the ARC-5 receivers, they’re in demand today – they were the “command” radio set for shorter range HF communications on many aircraft in WW2 together with the ARC-5 series transmitters. The BC band ARC-5 receiver was generally used by hams as a second, tunable IF for the BC-348 (which has an IF frequency of 915 KHz) to provide additional selectivity to the BC-348. The ARC-5 antenna terminal can be coupled to one of the BC-348 IF stages with a small capacitor, and use the ARC-5 for the audio output. This gives you a nice selectivity and tunable second IF without hacking into the BC-348 which is getting scarcer and scarcer.



  • There is a ton of information at http://netnow.micron.net/~kj7f/boatanch/bc348.htm check it out.
  • Contact W7FG at www.w7fg.com for a manual. Only $18 and a great investment.
  • I can find the exact model /manufacturer/tube lineup list for you if you need it, I just have to look into some of my Internet links. mbendror@villagenet.com
  • Look for a schematic in the gentlemans files. Also, the Surplus Conversion Books from the late 40’s and up thru the early 60’s have tons of info on this radio.
  • I have some of the CQ Magazine books on surplus equipment mods for hams, so if you see something that doesn’t match the original schematic we might be able to figure out what it was intended to do. (SBJohnston@aol.com) More on these in a bit…
  • There is some good info on BC-348s at the Military Commo List site(s):
    (specfically) http://www.telalink.net/~badger/millist/m7.html#a1253
  • There is a lot of information out there in old QST’s, 73’s, and the Surplus Conversion Manuals I, II, and III……..
  • Fair radio does have [copies] of manuals for all of the models for $12. (http://www2.wcoil.com/~fairadio/)
  • The CQ Conversion Manual listed sources for ‘Conversion Data’: CQ MAGAZINE:
    September 1956
    February 1959
    March 1959
  • http://netnow.micron.net/~kj7f/boatanch/bc348.htm
  • http://www.aade.com/hampedia/military/military.htm
  • http://www.qsl.net/wf2u/
  • http://www.qsl.net/wd8das/



This kind of sums all this old MIL stuff collecting up pretty well. I’d made an off-hand comment on how excited I was finding this little receiver, and here is the comment that I got back. I couldn’t have made a better “straight” guy on Vaudeville!

Q: Thank you for all your answers. Very interesting reading. And, this “mil” stuff is starting to grow on me.

A: That’s what that ‘MFP’ coating was for inside the old gear :-) :-) :-)


  73 Responses to “BC-348 FAQ”

  1. Update: looking with my oscilloscope, on a certain position of the variable I can see a self-oscillation starting on grid and plate of VT-150, the oscillator tube.
    How can I neutralize it? it’s the first time for me, I have no experience…

  2. Hi Paolo, is it affecting performance?

    Presuming your scope lead capacitance is not implicated and a scope fault scope not initiating oscillation,

    I guess number one, try another tube and see if it remains. Check all component values close to the tube and replace
    the capacitors one at a time to see whether it is one and if so ‘which’. The 348 manual gives a great deal of resistance and
    voltage information on each tube. Bear in mind that at this age the 348 can suffer high resistance joints, BFO issues, fungus
    in IF’s, resistor values all over the shop including infinite (cracked), leaky caps, soft tubes, sagging elements in tubes,
    insulation break down in shielded cables and I suppose ‘issues’ from components acting as antenna when specs are out…

    I’ve never fully read the service manual however the American manuals often had quite comprehensive fault finding
    information. I am ashamed to say that I am one of those ‘when all else fails…read the instructions’ people and quite
    fatigued from study at the moment so I hope my general answers may give some direction…Oscillation generally
    begins from the grid input and cathode grid plate interaction, which is why I first suggested try another (known good)
    tube….then the components close to the oscillator. Cheers

  3. Hi Jack,
    Thanks for your help. I’m waiting for a new tube to arrive, and I’ll immediately try it.
    For the moment, I have replaced all capacitors in the oscillator box, and a couple of resistors that had a raised value (more than 20%) and now the voltages are quite as expected to be in the manual.
    Before dismounting the 1st conversion box – detector box, I’ll wait for the new tube to arrive.
    The receiver is now very sensitive, maybe too much. I mean, with strong signals it shows some audio distortion, if I don’t reduce the volume/sensitivity control.
    I did rebuild the receiver as per in the manual, so now I have coaxial controls for volume and bias.
    I’ll post any further information. Maybe it will be helpful for other restorers.

  4. Hi Mark, did my December 11 response to Paolo arrive mark?…I think I forgot to fill in email etc?……Hmmm if I didn’t, it wouldn’t ‘send’ would it!….I’d hate to rewrite it! so might not..Please advise.

    regards Tony

  5. Hi…did everyone sort out their BC348 problems?

  6. Hi Tony….Long time. Yes my problem solved long time ago.

    Happy Xmas..

  7. Hi Goran…great news!…wish you also safe and Holy Christmas reflections. I have several BC348…I will eventually sell two…but it’s like a part of one’s life is severed. I have other WW11 sets being recapped (AR7’s then B-40’s, ZC1’s Command sets…TRC77 and so on. I have one AR7 which was the original set very modified and featuring in “Amateur Radio back in the ’60’s…great design but terrible workmanship sub-chassis…I’ve been tidying it but may e better to totally rebuild as with my BC342.

    I had the unfortunate experience of dealing with an AM group and each of them I find hard to regard as “Hams” though technically and commercially very experienced, technically far more than I am. One experience was the 342, sold to me as working ok ‘just a little noisy’ by a ‘highly regarded engineer’ academic. As the front panel looked as though hit by shrapnel…the 342’s…or some of them anyway.. seemed to have a paint issue…a new front panel was in the (very high-end price) deal. I drove 100k to pick it up. The front panel?…oh, couldn’t find it … only had a month… was ‘somewhere…I’ll find it and send it to you’…The set never worked. The panel never came. In the same group I was directed to an HF receiver of a type I wanted…’working ok…signals a little weak perhaps but he lived outside Goulburn NSW. I drove a little over 1000kms (each way) and picked it up. It didn’t work and it was mollycoddled on the way back.

    As with the others of the group I at that point admired and adulated I learned it was ‘come in sucker’, but worse..one stalks and abuses me when I advertise for gear. I am always polite when I could be extremely penetrating as I am a traditional member of the Amateur Radio Service…not a “Ham”. I never found that degree of predatory behaviour in ‘hams’ before the 1970’s. They were really very decent people amongst the HF fraternity. I think a new wave of Hi-Tech and Z-calls somewhat parted the ways between mindsets of some ‘new age’ chaps.

    So the 342 sat there. I’d pulled the main cap which was crook and this year got started on replacing the caps. I’ve gone from maintaining sets in original condition with their multi-cap cans, though externally, yes pretty much keep as-is. The elephant trunk connector on the front of the 342 does nothing to improve the looks of the already ugly 342, though the sets themselves are said to be extremely good. Why not rebuild the cans?….In part it’s owing to the carcinogenic interiors, in part to make the sets tidier, more readily serviceable and better in operation. The set from Goulburn I’ll sooner or later get operating. They are a set really worthy of using though I think they weigh more than a Collins URR391….mainly because built for submarine and other Naval engagement work. The original version….I hadone at age 16 and lusted after the more modern one…not I’d like the other!.. used the brilliant EF50 (and EF91) tubes…”the valve/tube that won the war” is an article on internet about the valves…part of the very interesting history is on https://www.dos4ever.com/EF50/EF50.html…Ofcourse at that young age I had no idea of all that or what a tremendous tube it is. I keep a few as ‘nostalgia’

    Getting back to it…For example I have a 348 which came from Holland early after WW11 with a professionally extended front panel. S-meters on 348′ are usually pretty badly done but this one is ok as located on the extension. All the labels are extremely professional and I think the set was used as a direction finder…maybe for nautical, maybe as a detection apparatus….maybe if a ham, for setting beam direction….but a lot of work just for that. The full or ‘technical’ impact of what seems simple switch on the extension “Simplex…Duplex…Peilen….Richting” for example what exactly was/is its function? The meter has a control below it….most s-meters do have a ‘zero-set’ but this one is graded ‘0-20’ either side of ‘0″ and marked ‘Min Reiniging’. Presumably ‘minimum deflection’ or ‘minimum variation’…Australia post dropped the set and smashed part of it (including the ‘so cheap’ 12AX7)…all of which I have repaired as close as possible to ‘perfect’ ‘as it was’ without damaging the paint and rewired the additional section. The antenna trimmer Bowden-drive bent and ultimately though gently approached, it broke…

    anyone have a Bowden-drive for the antenna trimmer, to sell?

    I should have pulled it out to fix it but the screw was jammed. Nice set….but what was it? who did it?… and why was so much put into it?…maybe some Hollander radio historian will be found.

    All my 348’s are interesting or have ‘soul’…there’s a feeling I get from the occasional set that says “I’ve lived brother’….though I feel no affection for the one on which many hang their hats “as used in the Enola Gay’.

    I was never as fond of the single-ended Q series as the g/c ‘R’ series…however I have both and it takes a bit for me to buy a ‘Q’. One of mine (from memory) I bought as it has an RAAF Label. One very nice “R” has been rebuilt with a “Q” RF deck and what ‘fascinates’ me is the serial is 1000000 on an ‘R’…when ‘they’ say total 348 build was around 100,000. Another, now sold has a USA commercial ‘rebuilt’ transfer on the RF deck cover. It was used here on a Catalina seaplane. Somewhere I seem to recall is one which had so many mod’s I just didn’t “get” it…I put it away until I completed my studies (a Masters degree) which I have just done. I’ll put it back to standard.

    Now here’s where I can reach out …I have another “Q” who knows someone might be able to give some background. A “Q” in ‘as new’ condition inside was modified by a company ‘Williams Shipping’ A new mixer (missing!!…what was that tube exactly?…Hmmm) 7 pin was used on the RF deck. The power is, I’m sure, the appalling American transformer-less variety which a 240-110V isolation transformer and (the arguable) earthing will give some protection but the dynamotor deck has extremely professionally built push pull output 2 x6V6. This would surely be to broadcast something like ‘Voice of America’ throughout a vessel or be set on 500kHz on some occasions or as a P/A system but there is no other evidence of the latter. Even the most ‘precious’ of today’s ‘hams’ demanding ‘broadcast-studio hi-fi’ would not need push pull volume.

    Two empty tube sockets under the set will be traced…one may be a driver/phase-splitter for the amp. The other..? I’d say the set is pre-product-detector but time will tell. The chassis (and tubes also) as said, is like new. Why interesting?…well all I learned was that Williams (of San Diego USA) bought a lot of ‘surplus’ gear and modified it for shipping use. So far I have got nowhere historically and my US ‘historical’ enquiries have received no response. I have usually found them not courteous enough to even acknowledge an enquiry….so I ask ‘can anyone out there help’ with the Williams history. I can provide photo of any of this gear through my own email…queribus@onthenet.com.au. This is the “Williams Ship Radio Company”….”Ship Radio Devices” of “San Diego California” information from the set itself…presuming it will stay with the email……oh oh!!…no….it won’t and I don’t know how to attach things. Their only address I have is “P/O Box 33 Bayview 3097” from their letterhead. I’m pretty sure they’d be ‘long gone’.

    Ok…so I’ll leave it there…hope some of you passing by find something interesting in it…and someone knows about Williams’…My regards

  8. whoops…sorry P/O Box 331 was Williams not 33

    How are you also, Paolo and Mark? I wish you all safe and reflective Christmas. I ignore age almost obsessively but, as soon to be looking for work until age 84
    and having just had my 74th birthday passed, I have very clear recollections ..not ‘memory-reconstructions’ as the courts prefer to believe of witnesses….of SWL and Amateur radio and services gear since 1955. I drift into that and then get back to the point. I have a Globe 303 I suppose you could call it ‘novice’ transmitter…plug-in crystal (at front panel) control which I am going to check and use in future….later bought the VFO for it. I have an RME 6900 which I’ve done a little revival here and there. As (bad) luck would have it it arrived from USA with the three most expensive tubes kaput. That and a 348 (but which one?!!) and when rebuilt the 342 and much modified AR7 will get a run. My daughters want me to sell off all this ‘stuff’ before I die….(and having Silicosis/Asbestosis…who knows when that will be) so I’ll get the AR7’s to the point of signal gen in audio out as reception here is pretty well non-existing in recent years…which started a year or so after I bought the 342 and B-40D…even my ‘hot’ Kenwoods get nothing but noise and occasionally on 40M and 30M some Chinese commercial stations at about 2-3/4-5(RS). Stuff includes rare books, aboriginal art and a lot of …ok well yes ‘stuff’.

  9. That comment beat my longer dissertation onto the site so it may make more sense if the other one appears.

    • I’m sorry that it took me a while to approve the longer one which got held for moderation. I was distracted yesterday by going to pick up a Teletype 28 ASR. Yay!

  10. Paulo…if still around…I just re-read the site. Going back to your 15/12/2017 email…..I’d do the mod I and others have done….split the AF and RF gain pots (I put the RF gain up in the Left hand upper area) Get your mains switching off the AVC wafer and put it on the af gain which should be a ‘switch pot’ 5000-15000 ohms should be ok for the RF gain. I’ve experienced motorboating sometimes when using a preamp….I think untying the gain controls could be an answer…even if not it makes the set more flexible. The designers deliberately kept gain low and your work may be (maybe) driving the set harder than design and brining it into oscillation or similar distortion.

    I’d like to exchange some photos with you, Goran and Henri.

    By the way Henri…I have an old place in ‘un hameau’ in the Cussac area….If you have no objection…where are you located have I asked previously)?

    Antiquity……Poor old Tim back in 2012 asked about value of a BC375 complete and brand new in boxes. As no one answered..in my opinion today $1500-2000 or more if Museum. One is for sale here…bare, no valves/tubes no coil boxes…$475.00 Australian. The tubes alone would cost $400 US, the coil boxes s/h $100 each…that’s nearly $1000 US…so new and complete and still boxed….it would be a bargain at $1500-$2000 even though the ART-13 superseded it…but did not entirely replace it. In my view its real value would be closer to $4000 but…who’d pay it?….you have to find someone who would…and someone would.

  11. Mark..Hi….did my long letter of today..arrive and is ok?..not on the site as far as I cans ee

  12. Hello,
    can anyone help me with a schematic of the BC-348-C or the BC-224-C ???
    The Netherlands

  13. Paolo…belatedly,I have a soluton to the oscillator situation….get back to me on france007@onthenet.
    com.au if you wish…My Regards

  14. Regarding “There is a rumor, but no hard evidence that I have seen, that Hallicrafters specifically made a drop in AC supply that replaced the dynamotor, this would be easy to do mechanically-it would just be a screwdriver operation, but if this is true there may be a concern that one side of the AC line would be tied to the chassis-a definite safety concern.”

    The Hallicrafters p/s was a transformer based p/s…none of your ‘killer chassis’ transformerless jobs as were common around WW11 in USA and UK. Australia didn’t permit the mad idea…which could see chassis live to earth (yes USA connected earth to neutral…which is how a neutral becomes a neutral. Through inconssiostent mains and outles and set wiring the chassis could becoe 110 or 220 volt to earth. Earthing for receiver in the days of computers and other noise generators may be better connected to an earth stake in conductive ground and fed through a short wire. This of course might see a potential difference between that earth an the mains earthing at the outlet.

    Isolation transformers are recommended for such sets however that merely removes one side of the mains from earthing….safer but for me ‘safe’ with those abominations is to smash them and junk them. …or build a transformer based supply…Many used silicon diodes which fried more than one “meddler” playing
    around the very exposed mains voltage. There is no nees to either wir or tolerate a BC348 in tranformerless mode.

  15. How do can you recieve the local AM broadcast stations? I would love to be able to tune them in. I remember seeing a YouTube video, but I cannot find it now. Is this a simple mod? Thank you.

  16. Hi…I don’t think there’s a practicality point to doing it Ben. There I think an early 348 (maybe not under that title) which included BC
    band. For its military purpose the BC band was dumped . The IF is 915kHz (kCs) which is middle of BC band. They used that frequency
    in part becasue the traditional direction fining for glide path was 200-400kHz or 200-500kHz if taking in emergency frequency…too
    close to the commonplce 455/465kHz if’s.

    I suppose one could build a converter tuned into the lowest band but again I don’t think much of it. With that era of aircraft radio
    why not buy a “command” set (ARC type) which covers the band?…They are rare (I have one) but turn up occasionally. I realise
    that’s not reallyanswering your question however and sadly short wave stations in English are disappearing whilst China is
    unfortunately spreading its power-mania propaganda(to compete with USA) seemingly that is needed to indoctrinate its victims
    (citizens at home and abroad). It has now resorted to petulant rantings in local media….criticism it would not allow of its own
    government. I acknowledge that shortwave has always been a propaganda medium no matter what the source.

    Now with FM the am.BC band has lost support but stillwould appreciate compliments in public, to keep it alive and out of the
    ‘digital’ mode. I like to listen to the BC band and so sympathise with you aspiration I looked around to find some specific 348
    conversion to no avail. I’ll keep trying though I doubt there was much interest.

    Another way to get the best from the B/C band would be to get an interesting older valve car radio..they had an RF stage
    and worked very well…or an early commercial set made for export..with an RF stage.Again none of that answers your
    question and you may have worked all that out for yourself. I’ll give anothr search later. My regards