Steve
Society Members
vintageradio.co.nz
Posts: 726
|
Post by Steve on Apr 3, 2020 20:32:00 GMT 12
youtu.be/4UoEk8XB4_oI've decided to try and learn some filming and video editing... It's not great but I'll either give up and stop torturing you all with it or I'll get better... Either way you win Part two coming soon Cheers, Steve
|
|
Steve
Society Members
vintageradio.co.nz
Posts: 726
|
Post by Steve on Apr 6, 2020 8:57:24 GMT 12
|
|
Steve
Society Members
vintageradio.co.nz
Posts: 726
|
Post by Steve on Apr 14, 2020 11:57:57 GMT 12
Part three is uploading now - the raw video is around 4Gb in size so it takes around 5 hours on my country-bumpkin slownet... so hopefully sometime this evening it'll be live. I have a few ideas for the next one - Pacific model 107, Pacemaker Leader Portable, Courtenay model 140... ? I'm thinking the 107 because I have the table and the console models. Neither works and I've never played with this style of circuit with NSC. The restoration queue is quite long, and there is a lot in it. A lot to choose from. This Rolax set was probably an odd choice for the first video in retrospect... but it was sitting on the kitchen table where it had been for months since bringing it home after someone at an NZVRS meeting sometime last year said I should take it home. I'm easily led (as opposed to a red led ) Now its off the table... although I don't know where it will go once its done. Maybe back on the table...
Cheers, Steve
|
|
Steve
Society Members
vintageradio.co.nz
Posts: 726
|
Post by Steve on Apr 15, 2020 11:21:41 GMT 12
|
|
|
Post by dada on Apr 15, 2020 17:01:03 GMT 12
Nice one Steve, Chrs, DC
|
|
|
Post by DHockey on Apr 21, 2020 10:44:33 GMT 12
Hi Steve I reckon go with the 107 for the next video. It is the more interesting set, both visually and from an electronic perspective with the NSC. Getting back to the Rolax. The circuit of this set leads me to believe that it probably had a EM speaker with a 1500 ohm field coil originally. 1000 or 1500 is the usual value in sets with the field in the positive side of the HT (Radio Corp etc). 2500 ohm fields are usually found in sets that employ back-biasing where the field coil is hanging off the centre tap of the power transformer, like in many Radio Ltd sets of the 30’s and 40’s like this one: www.vintageradio.co.nz/model/ultimate/uuIt probably doesn’t matter that much with a set like the Rolax, the HT will be a wee bit lower and the coil may get a bit warmer than a 1500 ohm would.
|
|
Steve
Society Members
vintageradio.co.nz
Posts: 726
|
Post by Steve on Apr 21, 2020 11:09:45 GMT 12
Thanks Daniel - I'm thinking the 107 as well - because I've had both the console and the table model for quite a while now and I really like them... they're ugly-cool. The console was Pacific's first attempt at art deco I think - they nailed it the following year with the Elite and it kind of went downhill from there. You could be right on the 1500 ohm value, although the HT voltage seems right with 2500 - if I go to 1500 I suspect the HT will be way too high (and I don't know if I have one, short of using an RCNZ speaker). I expect this probably had whatever was the cheapest available speaker at the time - its unlikely they had a Rola in it, but you never know. Its got one now I'm in the final stages of assembly of the radio at the moment, so the last video should be up in the next day or so - editing takes longer than repairing! I could have finished this radio in a day if I was just doing it as I usually do - I estimate it's taken about 2 full days per video to do it this way - but for the time being I'm enjoying doing it - I need to get better at not waffling, and also not taking long pauses that I then need to chop out. I have a lot of respect for people who can talk clearly for any length of time without saying UMM or ERR and pausing to collect their thoughts - that is an impressive skill I never really thought about until now. Cheers, Steve
|
|
|
Post by DHockey on Apr 21, 2020 14:59:29 GMT 12
Agree, they are a cool looking radios, it seems like they were going for the “make it look like skyscraper” look.
I think “talking to the camera” is an acquired skill. You’ll probably get better at it over the course of a few videos. Also once you have people commenting and interacting with you via comments and other avenues you will likely feel that you are actually talking to someone rather than just the camera.
Your videos are a good length, compared to other Youtubers. Some make videos of over one hour which is a bit much in my opinion and spend ages telling you which way to install your capacitors or constantly telling you how dangerous valve equipment is. If you’re going to waffle, waffling about NZ radio manufacturing history is quite good as it provides context for people overseas or those in NZ who are new to vintage radio.
The original speaker was probably a Jensen, I’ve had a couple of mid – late 30’s CRC radios with those in them, so they were definitely available in Christchurch at the time. Anyway, its lucky you had an EM speaker of the right size and in working order to install. One tip with those smaller Rolas. They have a habit of developing rubbing voice coils after the set has been running for a while. I’ve found the way to cure this is to run the set for an hour or so until the field coil gets warm and the rubbing starts. I then carefully slacken off the field coil screws and realign the polepiece so the rubbing is gone. I then tighten the field coil screws back up. The basket and field coil must be moving about a wee bit when warm throwing the alignment out.
|
|
Steve
Society Members
vintageradio.co.nz
Posts: 726
|
Post by Steve on Apr 21, 2020 18:05:58 GMT 12
Thanks Daniel, thats good advice on the speaker and I'll keep an ear out for any rubbing. I think I might have a Jensen speaker somewhere - but I suspect its an 8" (which most of my spares are). I tend to hoard EM speakers even when they're open in the field since that can always be re-wound but they're not making them any more... Thanks for the advice re: waffle too - I'll try to strike that balance between teaching people to suck eggs, be safe and learn new(old) interesting facts Its actually difficult to remember what I've said in previous videos as well - I'm finding myself constantly wondering if I've mentioned something already, and a couple of times I've noticed I said "as I've said before" when I haven't said it before... I hope I do get better at that - but that could just be old age and my mind on its way to the knackers yard! Length-wise I was aiming for around 30 minutes, but I think most of them have pushed out to around 40. The final might be a touch longer but I'll try to compact it or at least put a recommendation on that people watch it at 1.5x speed Cheers, Steve
|
|
Steve
Society Members
vintageradio.co.nz
Posts: 726
|
Post by Steve on Apr 22, 2020 13:37:04 GMT 12
Spoiler alert! Just editing the last of the footage now - hopefully the video will be up in the next 24 hours
|
|
Steve
Society Members
vintageradio.co.nz
Posts: 726
|
Post by Steve on Apr 23, 2020 9:13:12 GMT 12
|
|
|
Post by DHockey on Apr 23, 2020 13:30:13 GMT 12
Looks great Steve! I like how you have retained the original finish on the cabinet. I’m looking forwards to watching the video later on today.
|
|
redxm
Society Members
Posts: 20
|
Post by redxm on Apr 23, 2020 14:33:11 GMT 12
Hey Steve, nice set of videos (havent watched EP 4 yet). Obviously you have a lot of experience restoring stuff, But may I make a few suggestions that may also benefit others. The tagstrip you installed for the 240v connection has no insulation on it, the potential for electrocution to someone working on the set in the future is pretty high. If you can't solder the power lead directly to the transformer and need to fit a termination block, maybe consider an insulated one such as www.jaycar.com.au/15-amp-12-way-screw-terminal-strip/p/HM3200If I solder directly to the transformer I use heatshrink and if there is even the slightest sign of bare conductors I use this www.jaycar.com.au/liquid-electrical-tape-tube-black/p/NM2836 Is the wire you stripped from the computer power supply mains rated? A lot of it isn't if its from the secondary, I usually strip cores out of an old IEC lead, that way you can use brown as an active to identify mains potential later on. Im pretty sure Australia and NZ wiring rules are similar. Over here soldering an earth directly to chassis is a no no. It must be crimped to a lug then attached with a nut, bolt and star washer. Your method of clamping the mains cable is sound. Please don't take this the wrong way, I just want to make sure everyone stays around as long as possible restoring and enjoying these old sets. Off to watch ep 4
|
|
Steve
Society Members
vintageradio.co.nz
Posts: 726
|
Post by Steve on Apr 23, 2020 17:55:59 GMT 12
Thanks for your comments - no offense taken at all, I'm always happy to take on new ideas and mix them with what I know - this is how we learn
Yes I'm aware the radio has exposed mains internally within the radio - almost every vintage radio did, as well as potentially lethal HT voltages on many connections around the chassis - some even had potentially lethal voltages outside of the confines of the chassis as well (I love those old anode caps Philips had). Yes, they are a hazard to the unwary and I did consider what to do about it but in the end went with what you see - the liquid tape would be a good idea (although it makes the tag strip particularly unserviceable in the future) but we can't get anything delivered here at the moment, at least until our level 4 Covid restrictions are lifted. Your comment, 'the potential for electrocution to someone working on the set in the future is pretty high" seems a little contentious though - I expect anyone working on mains equipment to understand the dangers inherent in doing so. However, I agree that the tag strip could be made a little safer to avoid stupid people getting a Darwin award - and I will do something about that.
The secondary wiring used on computer power supplies is often 300V rated, and the stuff I have under the bench right now is definitely that - I'll check the bits I used while in there tidying up the mains wiring in general (which I intend to do when I can find my bag full of fuse holders, as I also want to add one of those in). Interestingly heatshrink is often 600V rated, but I tend to double it up for my own personal satisfaction on any high-voltage application where there is even the slightest chance of it touching something else.
I do take your point on the earth as well and will revisit the attachment of the earth cable. I am pretty sure you are right - NZ and AU regulations are very similar in that regard. Having said that, and while I recall also hearing that earth terminals should be crimped and bolted, I've just spent the last hour trying to find any regulatory documents that definitively state this - and I can't find anything. Does anyone have a link to electrical regs that outline how earth bonding is to be achieved in appliances in New Zealand? NZECP50 covers the repair of appliances but in my quick scan of that document I couldn't see anything definitive in there as to how the earth wire should be attached internally on a class I appliance.
As an interesting aside, this was the first image I found in a quick search of a computer power supply with its lid removed (just looking for a modern mains powered item to compare with) - note the exposed mains on the back of the IEC socket. I understand that if the mains wiring is contained within the housing of the product then that is considered ok to be exposed.
Cheers, Steve
"When choosing between wrapping people in bubblewrap or teaching them to be safe around danger I tend towards the latter - life is dangerous, but also fun. Unless you're wrapped in bubblewrap" - me, just now
|
|
redxm
Society Members
Posts: 20
|
Post by redxm on Apr 23, 2020 18:46:31 GMT 12
Steve I think the earth connection issue has been discussed several times in Silicon Chip magazine over the years. With the exposed mains these days you can discount common sense, it died out ages ago, not everyone who plays with radios (or any mains appliance for that matter) fully understand the hazards involved. The bloke you sell it to may be aware of it but what about 3 clowns down the path. Its only that watching your video you did get your hand close to the tag strip while it was running. Its the nature of the hobby that you will be faultfinding a set which is often unbalanced on the bench with it running. Certainly not a go at you, more a post that even if it makes someone stop and think then the words wern't wasted. The liquid tape can be removed fairly easily if required. I agree with doubling up on the heatshrink. The computer power supply does not surprise me at all. There is some true garbage coming out of Asia, your workshop lights for example. I get a fair bit of RFI in my workshop too. I run my radios through a mains filter that I scrounged out of something a while ago, its basically an IEC socket with a PI filter. I used to find that I could cure a noisy set by using a seperate earth stake connection, even if the chassis was earthed via mains. I had my incoming supply cable replaced which included a new neutral connector and 90% of the noise is gone now. The solar inverter is now its own little noise source.
Cheers Ben
|
|