LATE WIRELESS.

Star (Christchurch), Issue 18643, 24 December 1928, Page 15

LATE WIRELESS.

(By “AERIAL.”) From the Studios. There will be special Christmas Eve programmes at all the' stations tonight. The stations will be on the air till twelve o’clock. Programmes of a wide and varied number of items will form the first portions of the- evening s entertainments, the latter portion being devoted to Christmas carols, hymns and sacred solos. There will thus be four hours of entertainment broadcast from each station on Christmas Eve. Worthy of special mention is the relay by 2YA of the midnight mass from St Gerard's Redemptorist Church. K *£ •'* With children’s morning services, church relays and special studio concerts. the Christmas Day programmes will be full of the atmosphere of the occasion. The Boxing Day programmes will all be of the popular type of entertainment. 2YA will broadcast a description of a sports meeting during the afternoon and the other stations, while IYA and 4YA will relay results of races. x x *: ANSWERS TO INQUIRIES. “ Aerial ” will be glad to answer any question pertaining to wireless, or give advice on the subject. Correspondents should give their names and addresises, not necessarily for “ B ” Battery Trouble. C.D., Avonside, writes: —“I wish to thank, you, also H.H.E. and for your most interesting replies to my letter re ‘B ’ battery troubles. A few further particulars may help to arrive at a solution to the problem. About a month ago I took all the old caustic out, and found a black sediment at the bottom of each test tube. After washing the* plates, I replaced fresh caustic solution, but after several charges of about eight hours each I still found that they would not hold the charge. I should say that the plates should be quite all right, as I obtained a new lot quite recently to increase my batteries from 90 volts to 135 volts, and found the new set to drop just as much as the old ones. I have constructed the batteries as follows:—Two negative plates are bound with soft iron wire, one on each side of a postive element, and insulated from same by two small pieces (about iin wide) of rubber tubing slipped over each end of the positive plate. I have inspected all plates and they are not touching anywhere. Most of the positive plates have a coating on them of a deep red colour. I know this should be so with sulphuric acid batteries, but is this all right for this particular kind of battery? I have tested for ‘ local action ’ as suggested by H.H.E., and have found everything O.K. Trusting I am not claiming too much of your time, and again thanking you for your valued reply." In reply: The foregoing was submitted to H.H.E, (an authority on Edison “ B ” battery construction and repair) and he writes:—“The black sediment mentioned by C.D. is dust and other impurities from the caustic, the elements and the oil such as is usually floated on the tops of cells in most home-made Edisons. (As regards oil, use transformer oil). It is noted that, for insulation purposes, C.D. uses rubber tubing slipped over the ends of each postive element. I think this is where he has struck trouble, as the sediment piles up on the ledges of the rubber and, forming a contact path be tween the positive and negative plates, short circuits them. I have experienced the same trouble with several batteries I have repaired. The rubber acts well for a month or so, until the sediment piles up, resulting in the battery gradually failing to hold its charge. The remedy is to use perforated rubber strips. These can be purchased, at small cost, from any battery repair station. If you do this, I will be glad to know how you get on.” “ Aerial ” adds the suggestion that even though the perforated strips are new when purchased they should be wished in an antacid solution (sal ammoniac does well) before using in the Edison. After a thorough washing in a strong sal ammoniac solution, wash the strips in clean water and finally in distilled water. Also: Do not permit the positive and negative plates to rest on the bottom of the test tubes. Keep them suspended about an inch, if possible, from the bottom. In this way the sediment will take a very long time to build up before it reaches the, elements. —“ Aerial.”^

To J.E.W.: Will go into the matter this evening or to-morrow, if I can find time, and will post a reply.—“ Aerial.”