Are you sure those quarter watt resistors aren't Half watt??
I almost never see quarter want resistors in tube stuff.
Bill Cahill

well thats what I thought, but the parts list Im pretty sure says 1/4, but then again, U models vs non-U. I will likely use 1/2 or larger all over the place.

had some time to put into this, I deciphered enough of the power supply to redo it. Have no interest in keeping the stock can around for look, that radio will work, or at least catch fire when I am done

So see the pics below....

First off, I selected a 120ohm 10w resistor behind a 2.5amp, 1000piv diode

I mounted them to a terminal strip (something I REALLY am going to miss getting from radio shack) and then mounted all of this to some spare phenol I keep around.

I mounted all of this on top of the chassis so the diode cannot get hot and the cement resistor can bleed off heat.

That second 'transformer' I pulled the leads back up thru the chassis so they can solder directly. I put a small strip on the bottom, all thru bolted, that bolt and those 2 pins connected to it act as the common point for each cap, which goes to B-, which only touches the actual chassis after it goes thru a 220K resistor.

I used close values, the 40 became 47, the 33 became 33, the 50 became 56 and the 100u-25v I used a 100u-50v (section 4 of the original can)

The leads you see are for the AC input (black) and B+ after the 40u cap, transformer, 30u cap (red wire)

All the other lead lines are being replaced with 20gauge hookup wire (another thing I would get from the shack)

At the same time, I replaced the power cord with a polarized one, and am rewiring such the switch switches the hot side and controls the power supply, filaments and the 'pilot light' which is nothing more than a 7w c9? bulb.

After I initially inspected the radio I did in fact plug it in and it didnt burst into flames and after 20 seconds made the 'my rectifier cap is totally gone' growl.

As I go I am cleaning the chassis with steel wool and everything else. Most wires will be replaced, all wax caps (I count 12) and any small resistor. It does have some ceramic discs that use color codes, I gotta go refresh my memory how to read those, the same values per color as resistors, but the orientation...I think the standard is mmf? shoulda paid more attention in college...

Oh groannnn (face palm) Please say you didn't....


....use steel wool on the chassis.:eek:

tell me why not? its the light stuff I use on gun barrels - shines it right up. there appears to be no coating on it so it is free to corrode as it sees fit?

It creates tiny steel fragments that get EVERYWHERE are impossible to see and short everything imaginable.....Essentially you dumped electronic termite eggs all over it.

Better a face palm than a face plant (ouch).
Well, that sucks. Time for the leaf blower treatment I guess.

Seems like a real good vacuuming would be first in order, to minimize driving the stuff in deeper.

well we certainly do not want termites, electronic or or other. Fortunately Its my 53rd rodeo, I use the shop vac method ;-)

And lets be honest, its not the valve body of an automatic. But she is clean, working and I got one .03 dip to go - which is fortunate because I have exactly one left. I rebuild them in chunks to minimize surprises, about every 3-4 components I fire it back up. Very sensitive FM tuner. But horrible build, my zeniths are a lot neater inside and they can be said to suck build wise...

surprisingly the very crummy looking carbon comp resistors are coming out in spec, pushing the 15% envelope, but in spec. I do not have the hum the OP complained about.

How new of Zeniths do you have? Their tube offerings were among the best built sets among companies not solely dedicated to HiFi. Anyone that would say tube Zeniths were poorly built either has a last gasp unit, or is rather picky/snobby.

I have a number, the 7H8222Z (I may have that model slightly munged) was the first tuber I did. 21 (I counted) .01uf couplers. Mebbe they got a group rate. (1951 model designator, 1948 chassis designator). Im not being snobbish at all, these radios were assembled by hand in the electronics version of a sweatshop by essentially women earning 'egg money'. Not much rational thought to the layout. Now dont get me wrong, stuff like zenith 5Mxx etc chassis you can get working with cat whiskers and chewing gum - I never said they didnt work or worked poorly. There is a big difference.

And this bendix is worse. At least they made good brakes...



...now if you would see the Hallicrafters 4 band I just did....comparative nirvana

Comparing consumer electronics to Ham/communications gear (such as Hallicrafters) is like comparing a Chevy SUV and a military hummer. Sure they may both get you and your stuff around but the consumer use/demands and the way they are met are radically different. I almost included Ham/communications gear in with 'that companies not dedicated to HiFi' qualifier, but did not figure you owned any of that gear to compare.

Do you have evidence to back up your sweat shop claim? Because Zenith used to brag on their items that they were designed and built "by well paid American workers", and I doubt they could get away with saying that (or would even do so to begin with) if it were a lie.

Also unless an electronics company is a tiny fly-by-night garage operation the assembly line workers DO NOT design the layout of the chassis. The engineers or production plant managers/engineers do, then they show the line workers, and say "build it like this"....Though how good of a job those workers do at 'building it like this' is another matter.

He who forgets history is doomed to repeat it....

I actually had an nth cousin who worked in these factories from the 40's to the demise in the late 70's. She did radios, kitchen appliances, sweepers and lastly sweeper bags. All from New Kensington PA!

Anyways I obviously touched a zenith nerve but hey, Im equal opportunity, Im inside SS and tube stuff to the tune of a couple hundred of them a year - you see all types to the point where you can anticipate the task at hand before you get all the screws out.

The Japanese kicked our asses for a reason compadre.

Anyways the Halli was a 5R10 - hardly ham equipment. Just cuz It can receive many bands? so can a LOT of things - its pretty darn easy to tune into different bands once you have the 'radio' part figured out. In fact, Id bet that MOST of the big old top line floor standers from before the war (2) had more than one band - its how they communicated back in the day. This was of course before the FCC sold all the freqs to our corporate masters. Not much to listen to if you are not into digital carrier signals.

But any rate, lest we turn this into a debate of radio guts, I am done soldering in parts. All the wax is gone, all the power wires, some resistors, cleaned and lubed a bunch of stuff. It works. Does not smoke too much (im kidding) and Im now getting the smokers hack off the case.

everyone wants pick-sures

You gave evidence to what I already knew (women were a good portion of the assembly line workforce in electronics), but have failed to convince me Zenith's employees were underpaid or worked in 'sweat shop' conditions (which is what I objected to).

The 5R10 IS ham/pro SW listening gear. It is however the stripped down bottom of the line model. I've got it's big brother with more features (such as a BFO which only HAMs had use for back then), and tubes. After WWII FM replaced SW as the additional band of consumer interest and high end SW sets were limited to Ham's and passionate SW listeners mostly. If that were a consumer model it would not have a metal cabinet like that (Wood for the nice models and plastic for the cheaper ones had been basically standard since just before WWII).

SW has always been an international broadcast and ham band, and is still in use by many analog stations, but unless you are near the coasts, or atmospheric conditions are right you are not likely to receive much since there are few stations in the USA.

The reason the Japs kicked our buts was dumping and our squishy politicians not enforcing our trade laws properly (carmine has gone over that here on VK in depth a few times).

I currently have about 150 vintage radios (over 100 being tube) most of which I've worked on, and have had many pass through my ownership over the years.

You do nice neat work.

Well lets meet halfway: during that time frame the vast majority of electronics workers were women who worked in substandard conditions for substandard pay, except for zenith workers who had climate controlled safe facilities with no glass ceiling.

At any rate thank you for the compliment, hopefully it wont sit long in my shop before someone gloms it up. Yes, I sell the units I work on, I have no cherished tube units - I barely have room for my surviving silver pioneers and most of them are in the closet...but in the interest of full disclosure lest I earn any ire from the omnipresent trolls who feel that someone who sells radios has no right to ask about fixing them (yes, I was told that): I earn sweatshop rates for my work. I aint a gurl. Is it self sustaining, i.e. acquisition+refurb cost < sold price? Yes, Does it pay the mortgage? No, but the point is gaining knowledge, experience and keeping people in the loop. These radios can finish off a room. Even better if they play. Plus admit it, there is a certain panache earned when you know something far more technical than the people whose only achievement so far is being able to use twitter...

To sum up the bendix world, I wish I knew how to get a shine on old thermoplastic cases subjected to smoke. Nonetheless, it has a great patina and that cheesy white c9 looks cool (I wonder what green would look like? they make bulbs that size now that draw 3.5w plus LEDs....)

Finished product:


(next up, an slqd33 TT then an old post war wood case AMFM that works now, the wife is going to 'shabby chic' the case and I restore the guts...)

I'm guessing you talked to a bunch of snobs on AK. Whoever told you selling sets revokes your right to ask technical repair questions is full of crap. There were relatively few cookie cutter products made, and much of the non-generic stuff has various quirks that are not always easy to solve without help.

I buy and sell too...Some sets I will never sell, some I keep a while and grow tired of or need gone for space, others I buy to sell. Sometimes I make a profit and sometimes I take a loss to get back needed space. Ocasionally I just buy restore and sell something not to make money, but because I like the set (not enough to keep) and know if I don't save it, that will be the end of its existance.

Actually it was antique radios.com!

I asked a question about a couplet I could not find the SCM on in case i had to make my own... Some guy found out it was a radio for sale and behaved poorly. I ended up selling 2 units to this older lady for her and her friend that she gifted one to - they spend quiet times drinking coffee and listening to whatever KDKA has become today... (turned out it was not the couplet but rather a volume pot that went rogue to 2.25Mohm and cause this weird feedback loop that played near full volume all the time as it caused some sort of oscillation in the 1st AF tube. go figure.

generally I can avoid the snobs on AK if I dont engage them in the discussions of what power cords to use, what CD polish and how much bottled air to use in the listening room....(people with too much time think of some WEIRD stuff)

I can see some point of being bothered by someone asking a repair question on a set listed for sale at the time the question is being asked if no mention of the problem, or on going work is made in the for sale listing.

One should always be (and try to appear to be) honest with their customers.

well what happened is, I have a couple hundred radios not worked on, stored in a trailer we have. A lady came to the store and picked out one she liked and wanted to see them all. she chose another one that was in the trailer I had never worked on. I told her i would have it done by the gift exchange....boy did I push that close! she had a backup radio chosen in case I had no luck but I got er done by pirating a vol pot from another zenith amfm. (had to be a pot with switch)

the guy in question on the forum took issue to it being on a radio I intend to sell - hell I intend to sell them ALL - gotta make room for news ones somehow. He felt that ARF is only for collectors and users.

On the AK you dont get that as much, its pretty much a given most of the stuff is acquired, polished, sold. some acquire, refurb/fix, polish, sell. I am in the latter group, cept for the ones I keep for myself of course....for example my sx3800 and 3900 have instructions in the will if no family want them. I literally list the MINIMUM to sell them for.