I have an interesting problem - at least to me. I
bought a Crosley Battery set ( 527 ), which is no longer a
'fiver'. It is a 'fourer' Someone removed the 1H4 2nd
audio tube and re-wired around it. It still works.
I am trying to improve the performance of the set. I
have made a simple B plus supply by using a diode, a
couple of resistors and caps. The tube specs say that
I need a 2 volt supply for the filiments. The radio
will not work off a single 1 1/2 battery - not enough
sourcing current - so I put two batteries in series
with a diode to drop the voltage. It there a better
way to handle the filiment suppy? Also the radio
whistles alot and is not as sensitive as it should be.
Is there a way to improve this? Thanks

Hi Randall

Make a power supply using a small 6 volt filament transformer, bridge rectifier, caps and a LM317 regulator. See the following site for information on LM317:

http://www.national.com/search/search.cgi/main?keywords=LM317

Check the schematic here on nostalgiaair. To make the radio original and improve performance you may want to add back a 1H4G tube?

Norm

: I have an interesting problem - at least to me. I
: bought a Crosley Battery set ( 527 ), which is no longer a
: 'fiver'. It is a 'fourer' Someone removed the 1H4 2nd
: audio tube and re-wired around it. It still works.
: I am trying to improve the performance of the set. I
: have made a simple B plus supply by using a diode, a
: couple of resistors and caps. The tube specs say that
: I need a 2 volt supply for the filiments. The radio
: will not work off a single 1 1/2 battery - not enough
: sourcing current - so I put two batteries in series
: with a diode to drop the voltage. It there a better
: way to handle the filiment suppy? Also the radio
: whistles alot and is not as sensitive as it should be.
: Is there a way to improve this? Thanks

I had a Crosley 527 once. I powered it up on batteries and found it was noisy but had good reception/sound. Make sure the electrolytic cap. across the B supply is OK. A new 10 uF cap made mine quiet again--it buzzed like it was being run on AC even though I used batteries.