Harry Brown gave this radio to his granddaughter, probably in the 1960's It has now come to me for repair. Apologies for the sound quality in the first part of this video - I had microphone gremlins.
Full Marks Marks Don in Getting the Harry Brown Radio with HMV 61-51 parentride I like your new Rigol Signal Generator the old Leader did a sternly job Best Regards Ian,
Nice job Don. I'm sure the recipient will be well chuffed. Nice to see the subtle changes you made to make it more attractive without ruining its character. Cheers Lynton G4XCQ
Cheers Mack. Today I'm trying to get the MG up on ramps to work out where the oil leak is coming from. Not so easy - it's too low. And it's 38 degrees outside ... but I only get one weekend a week.
Hi Don. Nice restoration. A tip I got from the Vintage TV and Radio website was that a 100V line PA transformer can be used at a pinch for an output transformer (Jaycar MM1900) I have successfully used one in an STC 536 radio I restored. They are about $9.00 each.
Hi. I've heard that too but I've never tried it. I should grab a couple from Jaycar to keep as spares. These HMV chassis are notorious for open circuit output transformers.
What a super little job Don. I build my own amateur radio (morse) equipment from pre digital designs but post tubes so thoroughly enjoyed nosing into this one with you. No chickens! just an odd fly or two checking your work this time! (ha ha) Looking forward to your next project as it sounds like you are quite excited about it. All the best mate.
Hi Stephen, I did most of this one at night. The lights attract all kind of bugs but the flies are pretty active as the weather warms up. It's getting hot now. 40 degrees C today, and it's not even Summer yet! Filming here is always difficult: we live near the airport so there are always planes flying over. They seem to know when I turn on the camera lol. Then there's the train line a block away with a freight train every half an hour or so. Then there's barking dogs and the neighbours getting drunk & singing karaoke. Add chickens to the mix and it becomes downright impossible! The next radio is a 1930's STC brand console. I don't own this one either - it's a job for a friend, but it promises to be interesting. I just hope I can get it working!
@@Donno308 Oh mate I feel your frustration. I live in a terraced row among many so I have several households no more than 30 mtrs from my workshop so barking dogs, wailing cats and dysfunctional neighbours are a pain. Summer is the best time for me to film as I can start at around 4am knowing I have a couple of hours before you hear the crescendo of coughing, farting and toilet flushings from adjacent properties (ha ha). All the best mate.
Hi Don, we had a power outage just as you were bringing the radio up! It looks like a HMV 61-51. The power transformer is on an angle so as to fit in the cabinet. Really nice speaker grill. Glad you put vent holes in the back though. Quite a nice way of using an old chassis. Hope you’re surviving the heat. Unfortunate fire, but you’d have thought that would of learned from Canberra building an estate next to a pine forest😢.
Hi Andrew, Yes, it's bloody hot! We had a 20 hour power outage over Thursday & Friday during the worst of the fire. The fault wasn't fire related but there were no available resources to fix it. Anyway all sorted now and I think they're getting on top of the fire at last. One of my work colleagues is a volunteer firefighter so I guess he'll have a story or two. The Gnangara pine forest used to be on the semi-rural outskirts of Perth but is now surrounded by suburbia. The suburban sprawl is relentless and so are the developers, doing dodgy deals to get their hands on land that really shouldn't be turned into suburbs. And this is the result. Anyway I've been busy with the MG today. I've got it up on stands and I've been pressure cleaning the underside to try to pinpoint the oil leak which, as we all know, is a fundamental part of the design. Cheers
Hi Don. I wish I could send you some of the misserable weather we're having here. The humidity has been around 90% all day with that fine misty rain. Fortunately it's not too hot. I should send it back up to Qld and David! The power came back on just after 10am. It sounded like there were a lot of emergency services, 3 choppers were circling until after 11.00pm. So someone must have gone into a major pole. The leaks sound very familar. I had an Austin 1800 as my 2nd car. Really confortable, more so than my friends LTD and with more space inside. BUT, it ate the rubber universal joints like there was no tomorrow and of course leaked oil like a sieve. Keep cool,, I'm sure the heat will head this way eventually.
Don, you have made a massive difference :-D The i.f stages are peaked and it sounds much better :-D I don't think it would be easy to get the scale and frequency together, tracking is a bloody nightmare. I never mess with the tracking, i'm not mad, ok i'm slightly mad :-D
Greetings: I think it was David Tipton that showed how just measuring the AVC negative voltage even without à modulating signal will allow proper IF alignment. Just keep the generator level low enough to not activate the AVC gain. The negative AVC voltage will increase as the IF is properly tuned. Does not require the output transformer to be functioning.
Yes it's a problem when you get leaky filter caps. The radio just hums the tune and you can't hear the words. It makes the news less alarming though...
Was it a surge or was it cooked without any ventilation? Either way, nice job Don and adding the vents should extend the life. Catch you next time Dave.
Hi Dave Hard to tell now. My guess is that the OPT went open and the owner took this to be a power surge. Or a power surge finished off the OPT which was already on the way out. Power surges were common in the 80's and the power supplier paid out a lot of money to consumers for damaged appliances.
The reason for 6IX being different is likely not Alignment, 6IX originally started broadcasting in 1933 on 1240KHz and then moved to 1080KHz in 1935, 2 years later. The dial glass was likely from before 1935 originally. As this was a home made radio, it is likely the dial glass was recovered from a different radio that had been parted out. I always found it interesting that Australian radios would have station ID's onthe glass and rarely had the frequency. Quite different to a lot of overseas AM / Broadcast Band radios.
Hi, Yes I think Australia (and New Zealand) may be unique in having station callsigns marked on radio dials. Every overseas radio I have seen has frequencies or wavelengths marked on the dials, and, on short wave receivers, countries. In this case though, the chassis is from the 1950's and, as far as I can tell, has its original dial. I think there is a clue in the fact that the dial cord had been incorrectly installed so that the pointer ran in the reverse direction. In that case, none of the station markings would line up. On checking I realised that the stations that had been stuck on the dial were in reverse order to the way they would normally appear. So it seems that rather than re-stringing the dial cord, he just typed out the main stations and stuck them on in the appropriate places. Cheers
Hello from Spain, first of all congratulations on your RU-vid channel that I follow regularly. But I have a question between curious and silly, how do you make those pigtails so perfect? Well, go ahead with the channel and Merry Christmas, it's almost there. Greetings, Juanma.
Hi Juanma and greetings from Australia! Glad you're enjoying my channel. To answer your question, I use a small screwdriver form a set of "jeweler's screwdrivers" (about 1mm) and wrap the component lead around that. I use small pliers to push the coil snugly against the handle then pull the screwdriver out and re-insert it into the coil from the other direction and, holding the little coil with my thumbnail, bend the wire to come off in line with the coil or at whatever angle I want . It sounds complicated but it only takes a few seconds. I'll show it in my next video. Cheers
Those people out there who might be interested in following along start with the Car Radios made in 1957 which use vacuum tubes with a 12V heater and a B+ of 12V should be fine.
15:27 Perhaps the speaker coil is open-circuit. (If it's the radio's own speaker, that is. If it's your workshop speaker, then perhaps the output transformer is at fault. Just a guess).
Hi Don, That radio is certainly a surprise! Though functional, the cabinet is interesting. Using a fret saw to cut out the AB speaker front must have took a fair long time. It is not always straightforward to make a cabinet in which to house an existing chassis, and dial. Do you know who manufactured that radio’s chassis: it looks professional? I’d say that radio now performs as good, if not better than it did when Austin fitted it into its cabinet for its first time. Another super repair job my friend. Best regards, Phil
Hi Phil. Yes, it's a His Masters Voice model 61-51. They are a nice little chassis. My guess is that he got it from a radio that had been dropped, hence the bent mains transformer, fixed it up and put it in that cabinet. The front panel is Masonite, which isn't very strong and tends to delaminate so it would have taken some time & care to cut the speaker grille with his initials.
Great watching you work on this. What did you end up doing with the "ground" wire on the power cord? Was it connected, or not used? Just curious about that one.
Hi Tim I ended up attaching the ground wire to the chassis. I only left it off at first in case there was any earth leakage through those old capacitors. When that happens it can trip the RCD breaker to the house and my wife gets upset.
Hello Don John from England here, I loved to see the home made radio repair but at the end of the video you said the dial string was back to front which means the tuning cap was also back to front with regards to the dial plate does that mean the stick on stations markings was to correct this ?
Hi John. Yes. thinking about it later I realised that was probably what happened. My guess is that, having re-strung the dial, he discovered that the pointer ran the wrong way, so stuck the station callsigns on the front. I checked and they are in reverse order to what appears on the dial glass so that pretty much proves the point.
Hi. No, the chickens kept quiet this time. The roosters had to go as the neighbors were complaining. They were duly invited to dinner at a friend's place.
I enjoy working on those HMV chassis, although 95% of them have O.C. output transformers in my experience. A tip though; operating a set with this transformer O.C. is a good way to ruin output valves. Did I hear you say silvered mica capacitors rarely give trouble? Not here! I replace them before even powering a set up for the first time. For the last 25 years, I've found almost all of them to be leaky, if they have more than a volt or so across them. The audio coupling capacitor in question may be an ordinary mica type. It'd be highly unusual to use a silvered mica cap in such a non-critical position. Hope that helps.
Hi Stuart. Yes, I think it was just an ordinary mica cap. I've also noticed these HMV chassis often have O.C output transformers. It must have been a design flaw.
