#16
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EDIT : without an electronics or EE education (~ 3yrs EE study at a universality like CAL State Electronics and Solid State Engineering study (like me) or bench tech experience (like me >part time + short timer ) and concomitant qualifications all that sounds like unqualified and hobby opinions to me and you are wrong about the heater wires ( I was informed below ) on these radios anyway stick to your day job mate I Last edited by tubetwister; 08-15-2017 at 07:49 PM. |
#17
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Dude, just to reiterate, check the heater wiring to verify that the 1st audio tube's heater is at the bottom (ground) end of the string. If it's not, it could be introducing hum downstream of the vol. control
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#18
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IIRC even some transformer heater wiring and lead dress was very specific in something like a boat anchor comm radio or spendy audio gear and a there were a only a few AA5 variants and virtually AA6 radios , the pre 1936 AA5 variants and the different tube envelopes & sockets for the same bloody AA5 circuits and the superior Zenith T.O. variants Your edit that makes perfect sense . I tried to stay away from AA5 and AC/DC rubbish in the hobby but my 2 exceptions today are this deaf SWL specific model Hallicraftors S120 nostalgia radio for me and maybe a Zenith Transoceanic H500 legitimate AA6 variant . Benching TV & radios at a Magnavox AD when I was doing that there at 1967-1970 , Most of us understood a given signal path or output path tube order to function because you had to know it to fix the bloody things and where to start anyway . we didnt have all these web forums and web sites or FUD But your info here is not FUD .☺ EDIT 08.15.2017 20:30 PDT I just assumed anyone replying to me would know the mid century AA4-AA5 tube order to function order correlation that hasn't changed much since 1936 and we had had to know all that in our sleep in school and how to to build an AA5 in the lab too .and that was H.S. advanced electronics lab before college which wasn't tubes anyway 3 periods a day BTY Last edited by tubetwister; 08-15-2017 at 10:33 PM. |
#19
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I think I saw some electromagnet speaker AA5 photos . I amassed a huge old radio web image collection with actually thousands of images but I'm not so sure there were many or any of those electromagnet speaker AA5 past the 1936 reference AA5 revision but if they were I may have the image trus`me That other thing may be something if its off spec. with a (correct uf capacitor to output tube cntrl. grid we don't have now ) . so maybe that should be shelved for now. especially if we look at the cap uf in there at output tube contrl. grid as opposed to spec that may be bigly over volting output tube cntrl. grid now like I think it is and I see +6V on my DVM . I can verify so far the 50C5 output tube control grid input is indeed +6V and the output tube 50C5 GE tube data spec is specifically 0 to neg volts with no mention at all about the cathode only at a brief glance of pin out volts . AVC /First Audio and Output tube and first IF amp tube heater and plate volts are fine. I did not read the diode plate voltages at the 12AV6 First Audio AVC Duplex Diode Triode that are wired to each other in the radio and the VOL pot is not deaf anyway so probably nothing to see there given the vol pot is ranging normally and phone volume is normal but lots of distortion that may be something else ,a tube or one of the caps I ordered . I am sure if I had the parts and tubes like you surely have in your workshop this radio would be done , So that where it ends for me until I get my NOS tubes and or the caps on order, beyond that ,maybe tomorrow now the clever one at a time tube pull with alligator clip tube pin heater leads you mentioned I have the leads here at the ready Edit: oh you have any photos here or at the usual spots of your hoarders conflagration of electronics refuse or is it a nice tidy 200 radio collection? Last edited by tubetwister; 08-15-2017 at 07:10 PM. |
#20
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SRSLY no joke and it exact matches mica caps all over that radio and its a .0046 uf Mica vs an .001 presumably film cap it's supposed to have there per the schematic and the AA5 reference design that can go to .002 uf also who knows what else they did . I'm obviously not an AA5 or even radio expert like most of you here , so the input is all good and teaching me thank's During my career ,some of those screw ups and product were butt of inside humor or more or a PITA , IOW some misplaced wires would not suprise me in a USA mid century home radio ,they already put the wrong output tube cntrl.grid cap in that crude radio with 1936 AA5 budget model ciruits in a deaf SWL 1965 radio . It's almost criminal and that radio or a AA4/AA5 would be today because it can electrocute us without much provocation ! You cant make that up Last edited by tubetwister; 08-13-2017 at 03:52 AM. |
Audiokarma |
#21
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I also worked as an Industrial Electrician for 30 years, so I'm no stranger to even higher voltages. I have one of those receivers in my warehouse, somewhere. I remember working on it and it had a floating B- line. Trying to remember if it's U/L listed. On mine, someone replaced the 'lytic with a metal can type and installing it tied the B- to the chassis, which made it a shock hazard. I corrected that right away. Those type of SWL receivers generally didn't sound that great, mainly they were made for speech or code reproduction and not really for music. Also, that receiver was one of the last ones built in USA. They seemed to shift their production to Japan. Possibly, they used what left over! |
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QUOTE=dieseljeep;3188044]
I have one of those receivers in my warehouse, somewhere. I remember working on it and it had a floating B- line. Trying to remember if it's U/L listed. On mine, someone replaced the 'lytic with a metal can type and installing it tied the B- to the chassis, which made it a shock hazard. I corrected that right away.[/QUOTE] Quote:
Setting aside the selenium rectifier and Zenith T.O. with an RF amp , the last AA5 tube radio was basically a clone of a 1936 reference AA5 even the Japanese radios and that time they were not uncommonly rubbish products anyway IRRC one could get get a chep no name or maybe regency Japanese or Taiwan AA5 for less than $10.00 in the mid '60s with the currency exchange rates back then. IRRC Sony never made AA5 tube radios but I may be wrong and they got into the first Sony pocket transistor radios instead of rice cookers late like 1955 I think . I read the Japanese S120 Hallicrafters AA4 had Japanese parts or a lot of them ,thats one way they said to tell if they had a Japanese made S120 AA4 or whatver Quote:
OTOH This radio has elevated thd +n way more than it should or my other AA5 radios and the other radios above and the fixed hum that is too loud and garbles speech at the lower volumes . Again SRSLY 50C5 beam power output tube has the Wrong value control grid cap and that cntrl. grid is over volting +6v + more if factor in the negative volt spec. but its a work in progress . I will know more with the new tubes and parts it could be tube and or circuit faults or something ahead of the 12AT7 AVC First audio contl. grid see below The radio gives me the same distortion and same hum at the VoL. pot and center tap .head of the 50C5 output tube Lets allow an argument that I didn't buy this deaf SWL AA4 for music . Bd'cast AM Frequency response is typically 40 Hz–7 kHz with a 50 dB S/N ratio at best and this radio can't make either end . I been an Audio enthusiast since the mid 1960s & studied the popular digital audio codecs in depth more recently but not like what snob audio fools think hires is ,they knew what we could hear in 1950 and 16 bits is plenty if its done well , LOL those snob audio fools think they can hear different color tube plates in an amp with ~1% thd+n and a difference of adequate CT11000 copper wires & cables and AC cords vs the exotic metal cable fool stuff too and hires over good 16 bit in the same production but the industry is banking on those fools daily ! Lets allow an argument I may not the guy to be talking to about loudspeakers Quote:
I don't know if you attended electronics school but belive it or not we did learn some things an enthusiast may or may not know in some corners but we weren't on a TV radio curriculum for the most of it at all especially being near Silicon Valley if you know what I mean and we were all recruited back then , I changed study and career paths that ultimately paid and kept me more engaged and some would say well traveled I ended up with a generous fortune 100 company corporate retirement plus , at 55 . Quote:
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Lets allow an argument that aside from perhaps being reckless downplaying the lethal potential of these radios there may be folks without yours or an understanding of electrical current paths reading all this or have no idea what these 52 yr old plus radios can do to them without much provocation : no need to debate all that ,the science around this is settled science ) Last edited by tubetwister; 08-15-2017 at 07:33 PM. |
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EDIT : Well it was a cardiologist and sudden coronary by pass surgery without more than a days delay , wholly unexpected by me or my GP or anyone that knew me at all including the gym trainers . The analogy here is these radios are lethal and you are being dismissive about that and your GFI outlets are not foolproof and neither was my significant exercise regimen .if you can not see the analogy here perhaps have someone explain it to you . .True story here and ......We never know when the bogey man is coming . Last edited by tubetwister; 08-15-2017 at 07:21 PM. |
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BTW, I'm a little more than just a hobbyist, plus I have four years of Tech school, associated with my Electrician Apprenticship. Plus, several years of practical experience, that no tech school can offer! Why do you think, I knew exactly what set you were working on, if I didn't have experience with the faults of the set. Another thing, I've been equipping my workshop with GFCI receptacles, ever since they became available, something like 30 years. It minimizes a shock hazard when working on equipment like this! |
#25
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+1 Had the same thought.
Sounds like he went here for his medical work. https://youtu.be/jWMO3rAD98k?t=1m32s
__________________
Tom C. Zenith: The quality stays in EVEN after the name falls off! What I want. --> http://www.videokarma.org/showpost.p...62&postcount=4 |
Audiokarma |
#26
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???
__________________
Rick (Sparks) Ethridge |
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Consider all this : 1. You may believe you are an above average Millennial . 2. Where are your valid statistical data and test subject data stores or [citations] and or some PhD peer reviews and papers to support your statement . 3 Did you use trained or random test sample groupings for your conclusions,controlled conditions, any accredited test proctors or any clinician or standardized testing , 4. Did you use a statically valid number of qualified or peer test subjects? 5. Did you use reliable double blind ABX testing like we do in pharma research ,statistical validation,engineering validation ,field product reliability validation, random MTBF destructive & competitive testing and many disciplines or no ? 6. How did you arrive at your statistically valid conclusion or anecdotal subjective or cognitive bias hypotheses ? 7 . Let's allow an argument of how many of your radios statistically just needed a random tube substation ,some cleaning , new connections ,De Oxit or only obviously visibly bad discrete circuit parts ,just new circuit part hook up wires jusk electronic cables ,a RF or IF coil or related cap again visibly bad parts or tubes ,only a line cord , a pot or switch (s) ,recap instead maybe resistors .lyrics or a loudspeaker.or a comprehensive electronic restore . 7.a Le'ts allow an argument that most ME, EE, ,EE grad EE undergrad deals in statistics ,materials science ,electrical conductivity, circuits ,thermal design, micro circuits ,controls,software and HDWE , diffused silicon , metallic alloys ,refined base metals, elements rr diffused exotic metals......... , or fabricated materials ,network controls ,fail safe and and devices and the scientific method , what I missed here you probably can not imagine outside of a lab ,university or private sector tech ,industry ,materials , eng. ,science and silicon . 8 Let's allow an argument that Discrete circuit superhet. AM radios were not rocket sconce since 1939 or perhaps well before that and niether are yours or mine . 7. How is working on 200 or even 2000 collector or refuse radios a credible electronics qualification as with a professional vetran techician resume and concomitant qualifications . or an accredited academic and lab A.A. , EE grad or EE undergrad studies ? 7a. Let's allow an argument this would be absurd if you know better more on that later, 9 . There are those that say some Millinials a have recieved poor educations and were never thought to think critcally or value a good argument like scientific or geo political debates and supporting arguments like technical, engineering ,medical and science necesities . 9a. I raised a now grown Millinial ,extended millennial family & virtually most the friends when I wasn,t abroad or far (work) and lots of them are *or were* lacking desirable educational and employment or skills ,attributes or situational skills we found that in the 105 yr old Fortune 100 global company I retired from managing at also and some of them typically over estimated thier abilities with exceptions ofc.*** 9b. ***** This is not unto itself an indictment of Millennials at all there are many ,exceptions but more an indictment of our failing institutions .**** 10. Let's allow an argument that without concomitant education ,experience in the private sector or related pubic sector and qualificatins any given enthusiast may be confused about all this and over estimating thier abilities ????? 11. Let's allow an argument you appear to be wong about an AA5/AA6 heater order and Old coot 88 is the smartest one in the room abuot tube radios or more 12. I was there (ONLY part time short timer +_hobby ). I chose a different career and study than TV radio & ultimately no electronics beyond the current hobby and , ahem ....hacking PC 's maybe decades ago just to look but never private citizen except a prank to someone I knew with a restart out for them (from mail attachment , all the geeks did it then , Today hobby are Nix & Windows 10 PC PC, solid state ,digital CE repair only if I have to and I can ,digital codecs ,Window 10 software validation and I/O throughput Linear Power supply class A+B amplified devices like amplifiers and 5.1/7.1 AVR and PWM/PSU & complete LCD TV repairing , LCD TV panel LED today but not for$$ I dont need and not public and not frequent like a bench tech ) 13. You have to respect the EE's that make all this possible and moreover the real techs today and the old school techs that get it done and blazed the trails and figured out and fixed the many EE's or production boo boos and still do today in the field its not like a hobby at all . My radio her came new with the wrong 50C5 cnrtl grid cap 14. except for the good heater wire order and related heater cathode faults noting it getting all new NOS tubes anyway I have now I have what we call a null and what I aleady new here all along but din't call the folks on it and dismissive FUD about about the AA 4-5-6 lethal radio hot chassis that can fry someone without much provocation Nonsense about electromagnet speaker outside of the scope of this thread or 80 years now or about my radio and ( an unqualified opinion ) about my radios thd+n distortion and speaker that is poor one but not to this high thd+n I hear An opinion without any supporting arguments or direct observations or inquiries about the severity of the audible distortion ,comparable or ,at least the volume setting. A qualified conclusion or peer reviewed opinion result is called the scientific method where I was educated some folks may not be familiar with , and you missed something about heater wires you were corrected on 15. trus`me I can fix this radio on my own and your LCD TV or PC and more presumably without vacuum tubes ( I can fix some if that and figure out the rest by reading the circuits (reference design) ) and tube data and whatever testing I know how to do .You ever seen a discrete AM radio with a complex Compactron tube ? You now what scan line NTSC color TV demodulater (s) do or what they are ? >I worked on TV's with those in a TV shop and way more complex stuff ,some at CAL State ,more abut that later 16. IOW maybe ,Let's allow an argument to your day job instead of advise on these radios or get detail observant here ,presumably you are not an EE engineer or undergrad and who knows what kind of radio tech? EDIT : 08.15.2017 08.15.2017 17. I never mentioned where or exactly what I studied anyway ,since the subject is tube radio, . most folks don't understand it anyway ,you have to be there or in the business . 17.b LOL.. After High School Grade 10,11,12 Advanced Electronics & Lab 3 hours per day 5 days a week and some vac.,tube study + projects and same for Solid State and ,some computers and and lab inst.+ math drugery for all this ..................., Our HS instructor for 3 yrs was an E,E, and industry & spared no money funding all this in a new dedicated electronics lab building with frosty cool AC too and the best labs this side of a spendy university . 1967-1790 H.S, those were optimistic and superb upper middle class times for us with obligatory nice vacations amd some weekenders & summer (but coll.. prep drudgery lots' and I worked hard too also ) and America had the Apollo missions Then there was all this : 18. LOL before my unrelated career subject degree at Cal State my most significant related edu. was Electronics and Solid State Engineering study (~ 3 yrs) at CAL State that was not so much about tube radios and TV or a usually poor for profit tech school diploma mill study to a dead end job like a (** by now**) a vanishing TV shop bench job or fixing office copiers or printers in the field or pulling cables for TV content productions amd pooling CATCV cable and putting yip TV dishes or selling or Geek Squad at Best buy : 6 Years here TRUMPS a thousand radios tongue: full stop . . Last edited by tubetwister; 08-15-2017 at 11:18 PM. Reason: tidy |
#28
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They say "talk is cheap" ....
And , Thank God here at VK we don't pay by the word , cause this dude would have a $10K bill after a week of posting |
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PS , NO I most certainly did NOT read the entirety of the post before mine .
Like the old proverb , oftentimes the more words there are , the less is actually being said ....... |
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Last edited by tubetwister; 08-15-2017 at 07:23 PM. |
Audiokarma |
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