When I recapped my 531 console I also replaced the badly worn cloth covered power cord. I didn't opt for ordering the modern replacement cord and plug for authenticity, but installed an ordinary brown cord with a polarized plug from a new extension cord. Being polarized, this got me thinking. Since this set provides a coupling capacitor to the AC line for local stations without the use of an external antenna, I am thinking that I probably should have paid attention to the polarity in hooking the replacement cord up. My thought is that one side of the polarized cord is always neutral and bonded to ground in the breaker panel and probably doesn't make as effective of a coupled antenna as the hot side would, as it is connected to other wiring spread throughout the house on the same phase. Thoughts?
Also on this same subject, assuming that authenticity wasn't an issue as far as the power cord, would it be better to install a 3 wire grounded cord to this particular set to also have a good ground provided to the ground terminal? The documentation mentions a ground wire on a water pipe, radiator, etc.
1. Correct, if your "local" antenna is connected to the neutral side of the AC line through the blocking capacitor (35) inside the set to block AC from the antenna circuit, it will not be very effective. It would need to be connected to the hot side of the line through the set's built-in blocking capacitor (35).
2. Not necessarily. Even if your house wiring was done properly and is properly grounded, a separate earth ground is better than depending on the AC line ground.
Hello Tony, I also use the 18 ga stranded type "brown type lampcord" on my vintage radio restorations. As far as "polarity" on AC/DC type chassis with a cap between both AC connections, some folks use the "safety caps". Personally, If I have em', I use em", otherwise, a regular cap works just as well. And if you inspect old vintage AC plugs closely, none of them were "polarized" in the old days as far as size of the spades either. Neither were the house AC recepticals in those days, so I think it is safe to assume, enjoy your vintage radio as you have it wired now. If you want to be concerned on todays "correct phasing" from the breaker boxes in modern homes, install your AC cord (+ larger spade) side directly to the on/off switch in the radio chassis. As far as adding a "ground wire" 3-wire type AC plug, personally I dont think that is necessary at all. On vintage radios that have AC transformers, you can always add a 2-amp fastblo fuse on one side of the AC line to protect everything. Just my thoughts. Randal
Ummm, Randal...the wide blade of polarized AC plugs are intended for the neutral side of the line, NOT the hot side. The radio's off-on switch should be in the hot side of the line for maximum safety.
Hi guys,
The wide blade of a polarized plug is the neutral. Also if you look at the cord you will notice the insulation of the neutral side is ribbed and the hot side is smooth.
Steve
In "theory" your correct Ron! I have seen more modern homes in my area wired "backwards" as far as modern AC phasing these days. With 2 legs 120 v "split" at the meter box, using a neutral ground, most of todays homes arent "phased correctly" in the 1st place throughout new home elect construction. In the old days, you didnt have a "choice" (2-wire incoming 110 v ac) that powered vintage homes from the AC pole trans back in the old days. And didnt care of which way to plug-in your vintage radio unless you unpluged and flipped the AC connector over, Same size spades on each side of AC connector supplied by the mfgrs in those days. Was phasing correct in those vintage days? As far as "proper match" on modern AC lines, we cant always assume all todays modern recepticals are "correct" with modern day phasing sometimes either. Best test is using a AC voltmeter to "ground", then select your connections to chassis & switch, because every 110 v socket varies "coast to coast" in the USA for proper "polarity" these days indeed when supplying AC power to vintage radios!! The modern day electricians wiring homes really dont pay mutch attention to (+/-) when it comes to "phasing AC", so therefore, check your local connections, or your vintage "schematic wiring" could be opposite your desired results for incoming AC to your vintage radio chassis indeed! Just my thoughts, Randal
Randal, I couldn't agree with you more. My parent's home was built in the late 1970's, renovated by "professionals" in the 1990's, and is a complete wiring disaster! After brining in a licensed electrician this past Summer to figure out how to install a simple light fixture, the electrician shook his head in amazement at the sheer madness that was/is their home's wiring system.
For an old radio, wouldn't it be a good idea to plug the radio directly into a surge protector?
Finding a house that has it's polarity mis-wired is not common. If you question your house wiring, you can measure the AC from the smaller outlet hole to the center cover screw or a radiator or some other known ground; or you could buy one of those cheap yellow socket testers and be guaranteed of proper wiring.
In all radios that I own or have serviced I use a polarized plug with the smaller prong (line) going to the switch. I also disconnect any capacitor that is connected to this line side but always leave the neutral side with a cap.
The difference in reception will probably not be detected; there is an awful lot of capacitance in the wiring and whatever RF signal that is on the line side will be coupled into the neutral side. This capacitance will NOT be in pre-1930 houses with knob-and-tube wiring; even so, I have never found a difference in reception.