Atwater Kent Model 43 "coffin style" find.
 

I walked into an antique store the other day and see what I recognize as a 1920s table top speaker with the wires going into this strange looking box that looks like a child's coffin. I took the lid off of the box and there like new money are all these shiny old "big pin" and "globe" tubes. Too bad I think; another farm radio or DC battery type that I always skip over.

Then I notice an AC power cord. Did someone wire in a plug to one of the A or B connecting wires? I've seen that before! Finally I could see enough to know that there was a transformer and a #80 rectifier tube. Indeed the radio was an AC/DC set. Wow! I normally cut off my collecting years in the 30s when superheterodyne AC/DC sets had become the norm & thus know very little about the early T.R.F. stuff, so I was caught off guard on this, but pleasantly surprised.

The man running the store said that the radio worked, but he said we would have to take it outside in order to pick up a station. It took both of us to move the amazingly heavy set! We ended up plugging it in and weren't able to receive a station. A point in my favor for talking them down on the $75 price tag. I was happy just seeing the set come on with a working power supply and audio section with nothing getting hot except a ballast resistor in there. The dial only went from 0 to 100 cycles, but I found out that 100 is actually 1Khz. The set is SUPER clean with all cloth wiring like new, paper labels intact on the chassis, and what I assume to be original paint on the metal body.

Got it home and was able to clearly pick up one station. It doesn't seem to even faintly pick up anything else. It's the preaching and gospel music station which is OK, but gets a bit old. I wonder if there is a way I can rig up a converter via another radio sort of like the FM converters worked in car radios. FM would be great, but I would settle for more AM selections.

So there you have it. If anyone has any thoughts, comments and/or suggestions; please let me know. Oh, and I was able to talk them down to $60. I think it has to be worth that.. What comes around really does go around I think. A few years ago I more less gave away an AK model 20 with the matching speaker horn. It needed a proper home

I have always called those "bread box" radios myself...

I have heard the older type called "bread board" but all material I have seen so far on these refers to them as "coffin style." A guy on the AK forum where I put another copy of this thread said that coffin style was what the old techs called them. The thing really is reminiscent of a bread box though more than anything. Maybe a sea chest. Who knows? It's just interesting...:thmbsp:

Have you connected it to any sort of antenna? Even a 5 to 20 foot length of wire should help considerably.

Note: the 0-100 scale relates to the % that the variable capacitors are "closed"... The tuning range should be the standard AM broadcast band, with the higher frequency stations likely appearing near the "0%" end, and tuning to the lower frequency stations as the capacitors are fully meshed (100%).

EDIT add : If you are hearing the religious station at the dial position shown in the photo (20%) it would be near the high frequency end of the dial... possibly WFIC 1530 kHz in Collinsville.

jr

Nice radio. First bread box is the common name for these. Coffin style is longer and has a hinge lid. The breadboard style is just a flat board that the components were attached to and are the earliest style. Second try a much longer wire for an antenna and a good earth ground. For more info check out this site; http://www.atwaterkent.info/ They have a lot of good info on Atwater Kent radios.

Yes, I have tried a 8 ft length of wire, a UHF "bowtie", and from an old Zenith Transoceanic 500 radio I robbed the Wave-Magnet as well as the telescopic antenna. None of these had any effect unless my body was in contact except the Zenith antennas. The Wave-Magnet only had some response, but the same sets large telescopic gave me an acceptable result. The result being a surprise to me as telescopic antennas are more suitable for lower bandwidth/higher frequency applications like F.M. transmission. A coil of wire is normally more suited to A.M. reception in theory at least.

You hit the nail on the head with length. An Atwater-Kent service bulletin I have recommends quite a bit of wire and use of an earth ground, If training memory serves me right, an AM antenna is supposed to be arranged in loops or coils, but no mention of anything like that in the bulletin. I have a 30s Silvertone cathedral in which someone ran a bunch of turns of copper around a cardboard form as a homemade antenna. Maybe I will try that one out.

As it stands I only pick up the one station out of Eden, NC or perhaps Reidsville. These would be in closer proximity to my home in Ridgeway, VA than WFIC at around 25 miles distance.

That is a tuned rf radio. You need to check to see that when you tune the dial
each tuning capacitor is moving, and that they are in some type of alignment.
Rough alignment might be as simple as seeing if they are all in sync through
the entire range of the dial.... Then check with a signal, and a scope at each
stage to be sure each is tuned to the same frequency when the dial is at
that point.....

Looks like a really cool radio ! I'm sure you are going to have to also put up a
good antenna for that set to work well.... Good luck !
Keep up the postings, I'm interested in seeing how it goes.....

Pretty much what jr tech said....

.

These old TRF sets do not have the high gain that more modern superhet sets do... you need a length of wire stretched out (not in a little coil) to do the job. 20 ft of wire stretched across the room is a start, but 100 feet is better! A good ground is also necessary for optimum performance. Remember, we are dealing with long wavelengths here, the middle of the AM broadcast band is 300 meters wavelength contrasted to the FM band which is about 3 meters. Your little UHF bowtie is designed for even shorter wavelengths ( 60 centimeters or so)... not much help for the AM radio band.

jr

Yup !

I got an old SC 60, Super Het. but still works like a champ with a good
ground, and a good long antenna wire..... I had 120 feet and wow it
pulled in good am and the sw was just amazing....

.

I've got an AK 40 that I use with an RCA 100-A speaker (better volume and power than the AK units I've tried).
These are finicky and interesting beasts having strong tubes is important for decent reception...Heck you can even change sensitivity by shuffling the type 26 RF and AF tubes. The gain is low and there is NO AGC so RF signal strength translates directly to audio gain, and weak signals will have very little volume (medium ones ain't much better). One trick with these is to loosen the set screws on the end pulleys with a station tuned and adjust the tuning condensers for best volume so the caps track each other better. You will need a long wire to get any stations that are not local and or nearish 50KW flamethrowers. I use a air core loop out of a 40's knight radio as an antenna for mine, and it only gets the local Milwaukee stations with decent volume. I can get the Chicago flamethrowers but with rather weak volume. Your set could probably benefit from new coupling caps and a check of resistors on the tuner chassis.

You are fortunate to be near enough to some big city "flamethrowers" that a small loop will work on an AK-40. The area around Ridgeway VA is *not* covered with strong signals (most of the closer ones are 5KW or less). I sometimes use 4.5 foot tuned outdoor loop for AM DXing with an Icom 8500 communications receiver. Although signal strength is much lower than that obtained with a 100 foot "longwire", noise is reduced considerably *and* it can be rotated to *null out* interfering stations
http://www.videokarma.org/attachment...8&d=1280607318

jr

Ridgeway AM :

http://radio-locator.com/cgi-bin/loc...sort=freq&sid=


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As stated, these sets were intended to work with long, straight wire antennas, preferably outdoor. Barring that, as long a wire as possible indoors stretched around the room will work some. Loops and telescoping antennas just look like a short wire to a radio like this. It needs length and stretched out, not coiled up in any way. Recall that AM DX signals improve at night. Also a ground connection is important for them. By the way, this is an AC radio, intended to work on Alternating Current only. Some later transformerless radios were called AC/DC, because they could be plugged into either Alternating or Direct Current. There were places particularly in large cities where some sections had DC. I don't think there is any of that left now, the whole country being on AC.

That AK model 43 would probably get only one station out here where I live, in northeastern Ohio, unless a really good antenna were used. That station is a 1kW days/0.5kW nights talk station on 1460 kHz. I am about 30 miles east of Cleveland and some ten-fifteen miles further than that from most of the Cleveland radio stations, all of which have their towers located west of town.

That this AK radio does not have AGC doesn't help matters much, either, at least in weak signal areas. It would probably receive the "local" station here with decent volume during the day, but when the station cuts its output power in half after dark, I doubt if it could be heard unless the volume were turned up as high as it will go, and even then I wouldn't count on hearing much of anything. The 50kW stations from Cleveland wouldn't produce room-filling volume from this set either, because of the distance (about 35-40 miles) from the towers and the fact that some of the 5kW stations cut their power output and/or have directional signal patterns at night. You probably wouldn't hear smaller stations (under 5kW) at all on this radio unless you had a really good antenna.

I am convinced that those early Atwater Kent radios were designed and built for strong-signal areas, not more than ten miles from the nearest station(s). This probably wasn't a problem when these sets were new, as radio itself was in its infancy in the '20s-'30s and there weren't that many radio stations in those days, anyway. Those stations that were on the air at the time had no more than 100 watts of power or so; the big 50kW ones didn't appear until the '40s or '50s, with the notable exception of WLW in Cincinnati, which had a 500kW(!) transmitter in the mid-1930s. I bet anyone in Cincinnati with an AK model 43 probably could hear that station (and little or nothing else) with room-filling volume--and then some. That 500kW signal would swamp a TRF radio in no time flat. Of course, with that much power, who even needed a radio to hear it? I've read reports of people having heard WLW on bedsprings, on the burner coils of electric stoves, etc. until the FCC stepped in and declared a 50kW maximum output power limit for all U. S. AM radio stations. For folks living on farms near the station's towers in their 500-kW days, "seven hundred WLW" was the only station in town.

BTW, the 50kW rule apparently does not apply to radio stations outside the US, especially those near the border of Arizona and Mexico, some of which run as much power today as WLW was belting out in the '30s.

On the other hand, DXing was a fairly common activity with these old TRF sets. My parents grew up in the midwest (Nebraska) on farms in the 20s, and both related childhood memories of evening listening to stations across the country from New York (early in the evening) to Los Angeles (later in the evening). THE SECRET; BIG LONG ANTENNAS, stretching to barns and other out-buildings 200 to 300 feet from the house, as well as a good water-pipe ground. The evening news *was* actually "live from NY" and "live from Chicago", "live from Denver" and "live from Los Angeles" most every evening (if there were no thunderstorms). Fun times for early radio listeners.

jr

Yeah, I have the "Double 1st Cousin" to this set, & they LOVE BIG, LONG, HIGH-UP antennas. Give it what it wants, & it'll likely pleasantly surprise you. ESPECIALLY this winter.

Although there may be exceptions, all the radios of that vintage I've ever seen cover only up to about 1500 kilocycles (or "khz" in modern terms. Bleah:grumpy:).

A friend of mine has a an AK 40 too (he convinced me to fix mine after I fixed his) and he has received Canada, Texas, New york, and some other places on his set with a similarly poor (albeit more highly tweaked) antenna....Though he is using 1920's headphones that can put out a surprising amount of volume.

I have a two model 44s, which have a fourth TRF stage. They are fairly good performers.
I certainly can DX with them in my quiet room.

Also .. with these coffin AC AK sets you don't need a ground like you do for a battery set. The AC line acts as the other side of a dipole antenna. I've run antenna simulations on typical house wiring and yes, it really does.

You should ohm out all your RF coil's, especially the antenna coil. Back in the day it was very common for a long wire antenna to take a lightning strike. Or sometimes the fine wires just open up from copper corrosion, although I doubt that's the case on such a well kept set. That one is a real beauty.

Your folks probably didn't have to deal with 50kW powerhouse radio stations in Nebraska in the '20s. My understanding is that most radio stations of that era were extremely low power (by today's standards), most folks were listening to out-of-town or even out-of-state stations, and there weren't that many radio stations in the entire US at that time. Cincinnati's WLW in the '30s was an experiment that was cut short by the government, because its 500-kW signal was wreaking havoc with other stations in the US and even in other countries; the station was forced to cut back to 50kW at that time. No other US radio station that I am aware of ever attempted such a bold experiment; they couldn't if they wanted to, since the FCC eventually capped the maximum power output any US station could have (under certain conditions, of course) at 50 kW.

DXing in the midwestern US is probably much more interesting than it is in other parts of the country, since a radio listener living in the midwest can likely hear stations from just about anywhere, including the West Coast. Nebraska is near the geographical center of the US, so even with a modest DXing setup one could log many stations in a short period of time. There is much less noise in that part of the US as well, the most interference probably coming from tractor engines and the like.

DXing on the East Coast or the Great Lakes is possible, of course, but the noise level, especially these days with computers and other digital devices, is often high enough to mask extremely weak stations. Case in point: I live in a 12-unit apartment building, 30 miles from downtown Cleveland. I often get noise that sounds like TV horizontal oscillator harmonics between stations on my radios, especially my Zenith C845, which has an RF amplifier stage for AM and FM (one tube functions for both bands). That RF tube amplifies everything the antenna receives, including noise, making it nearly impossible to hear anything much other than the big 50kW stations such as KYW in Philadelphia, KDKA in Pittsburgh, WMAQ (now WSCR) in Chicago, et al.

Other than those stations and the 50kW stations I normally receive from Cleveland (plus a 1kW/0.5kW day/night station in the next town south of here), I don't get much of anything at night other than the HO harmonic noise I mentioned earlier. The smaller 5kW stations in Cleveland usually change their signal patterns at night to favor the greater Cleveland area, so I rarely hear them. One station in a far-eastern Cleveland suburb absolutely drops into the noise shortly after sundown. That station isn't very powerful to begin with (500 watts during daylight hours); their nighttime signal is only 42 watts and directional to the Cleveland area at night, so it couldn't reach my area even under the best of conditions. I once emailed the station's technical department to find out their actual coverage area and found, in the reply, that their 500-watt daytime signal is not meant to reach my area, let alone anywhere east of here...and at night, their 42-watt sharply directional signal is only meant to be heard within about ten miles of the transmitter site, due to several full-time stations on the same frequency. The station had to install additional towers to keep their signal within 10-15 miles of the city of license at night, if they were to run 24 hours a day (the station for decades was 500 watts, daytime only). They have since put their station's audio online, on their Internet website, so the limitations on the signal's range are not nearly the problem they once were, but that's another story.

Here in Champaign IL, in a rather noisy building, with a good receiver (say an RCA 121) using my 15 inch loop antenna I can get one (or more, interfering) stations on 95% of frequencies at night. In fact, I can do almost as well with my homebrew 2 transistor regen, just one tuned circuit.

AFAIK there weren't any "flamethrowers" in Nebraska until the late 40's.

Local antique store has had a set like that for a while. Original price was 295 but the last time I was in there they came down some. Still a lot more than I'll pay for a radio. I don't recall if it had a plug though. Good find.

Thank you all and for a lot of good info and interesting reads. Back on the first page someone asked if I had made sure that the three variable capacitors were turning in sync. Indeed they are via what looks like leather strands.

I can't find a need for any repair that has been mentioned like coupling caps or whatnot. The radio works fine. I just didn't know what I was doing as far as properly operating it. On superhets; most of the time if you need an external antenna at all, nearly anything will work. Even an old UHF bow-tie! LOL! Duh! That was pretty dumb of me, but I was trying everything.

With a set that old in the great condition it is in, I hate to say it but it's going to end up more of a conversation piece than something that I use regularly. I am working on getting one of two Zenith Transoceanic 600s working. One is actually the brown leather case model that supposedly is the mother-lode of that type radio. I like the black one better, so I will probably let go of the leather one to recoup what it takes to get the other going.

I do plan on stringing a lot of wire and grounding to my wall receptical on the Atwater Kent just to see what it is capable of. I replaced the #80 rectifier just because I had others that tested stronger. The radio seems a bit louder, but that may be my imagination.....

Those straps (they are brass on a AK40) LINK the tuning caps, but they are most likely NOT optimally aligned! The pulleys those strands are wound on attach to the tuning caps with set screws. Tune a station, loosen a set screw of a pulley NOT on the knob shaft, tune that cap INDEPENDENT of the others for best volume, repeat for other cap/pulley not on knob shaft.....This is to a TRF set what IF alignment is to a superhetrodyne. You should see some to MUCH improvement from doing this.

The bands should be reasonably taught to hold that adjustment...If they are not, then there should be a way to shift the caps in their mountings to tighten the bands....It's been a while since I dealt with that procedure so specifics are not coming to me.

Hey, thanks Tom. I will give that a try. I still haven't gotten around to applying an ample antenna. What I do pick up is clear and reasonably loud considering what it is. I really don't know how loud that loud would have been then, but it easily fills the room.

many stations were low power when that radio was made, one of the first milwaukee stations (WSOE) had a 150 watt transmitter in the mid 20's. People in rural areas didnt have much chance of picking up much in the daytime. The early triodes had a gain of maybe 10 at best. The introduction of screen grid tubes in 1929 or so really was a revolutionary improvement.