[BILL]

My 22 year old daughter asked me if she could have a old console radio for her dinning room , I ofcoarse said yes, having over 500 radios, in 1991 I fixed up this 1930 Lyric "J" little console,very nice looking, used it as a working display at a local radio station's 50th aniversity,[1941] played great all that day, then the radio was put in to storage, got it out last weekend. This radio's chassie is a six tube, counting rectifier, TRF, uses three 24's for RF amp, and an other 24 for detector and a 45 output,
The radio played but if you turn up the volume it will osilate, like the early 1920's regenative radios , all the volume control is, is an antenna trimer , we don't have much of an antenna, my daughter is happy with the volume and sound it has ,but I'm not! OK, what's happening? is it feeding the signal over and over in the detector like an old regenitive ? maybe a bad mica cap?

[exray]

I wonder if changing the antenna length would affect it? Maybe add a small cap, say 100-250 pf range?

The other thing that comes to mind are riveted ground connections or shields in general if it has been sitting idle for so long.

And if you have a variac handy you might try dropping the AC voltage to see it and see how it goes.

GL, Bill

[Texasrocker]

All very good advise indeed Exray!! Also, if ever a old chassis-design could ever benefit from making sure orig "tube-shields" arent missing,and actually used where needed, the TRFs are a classic case of needing them in most cases! As a old-timer radio tech once told me,all mfgrs TRFs chassis are: " as touchy as a old-maid at a stagg-convention"! (hee hee) No wonder most Atwater Kents used metal-cabinets as a overall chassis shield with a pop-off top lid? All my TRFs work well with approx 25' outdoor longwire antenna. Seems to balance well with all my personal sets. Todays more powerful AM local broadcasters transmitters also wreak-havoc on all the old TRFs for overloading the antennas. Thats where your suggestion of adding the cap helps alot too!! Ive used many a aluminum beer-can with both ends cut off to mfgr tube-shields for these type sets with good results also. The TRFs are super-touchy indeed in todays world of mass generated RF! Most better TRF chassis designs can even receive RF generated by most nearby neighbors washing-machines during the spin-cycle also!