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Author Topic: $20 score  (Read 8800 times)
AC5UP
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« Reply #30 on: November 20, 2011, 06:33:55 PM »

Probably not.

The filament string in a transformer operated set is usually wired in parallel so all tubes get an equal surge that's somewhat cushioned by the transformer when the power is first turned on. Remember that a cold filament has a resistance very near a dead short. In the case of a series filament set like your AA5 the filament drawing the least amount of current in the string will light up brighter and hotter than normal while the rest of the tubes are coming up to temperature. If all the filaments are within spec at exactly the same current rating this isn't a problem, but I can guarantee you that tube filaments often have a loose tolerance.

A filament saver (also called a Globar Resistor) is a thermistor that presents a higher resistance when cold then goes to a low value after it heats up. It acts like a current cushion in the filament string and typically adds a few Ohms when operating normally. That's why you can't test it like a standard resistor and shouldn't be concerned if it runs hot. It's supposed to.

Best test would be to measure the tube filament voltages after the set has had a five minute warm-up to be sure they're reasonably close to normal. The only drawback to a Globar is that the set takes a little bit longer to start playing from a cold start..........
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N4NYY
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« Reply #31 on: November 20, 2011, 06:34:42 PM »

I will leave it then. I learn something new every day.
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NB3O
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Posts: 49




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« Reply #32 on: November 21, 2011, 07:06:54 AM »


"Either way they're 50's tech and it's my understanding they don't age well."

I remember dating a YL.............oh never mind.
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N4NYY
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« Reply #33 on: December 29, 2011, 05:35:43 PM »

Nelson,

I just finished my refurb of the Philco B-570 (new caps, resistors), and I picked up a station in Boston! WBZ1030!

I am in Philly!
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AC5UP
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« Reply #34 on: December 29, 2011, 06:13:54 PM »

   Dude.    We need to talk...................

Many moon ago in Northeast Philadelphia I had an RCA console in the basement that was tweaked about as well as a noob with no test equipment could tweak a pre-war console. This was in the 60's when radio was worth listening to, hence my motivation. WBZ played Top 40 but was lame in comparison to WABC (770) in NYC and WKBW (1520) in Buffalo. None of them presented a reception challenge, nor did KDKA (1020) in Pittsburgh. What separated the players from the pretenders was WLS (890) in Chicago and WWL (870) in New Orleans. Then there was WOWO (1190) in Ft. Wayne, Indiana.

As you're aware, there's a very large signal on 1210 and for a consumer radio 20 kc's of separation is a little tight.

Used to be I knew the call & dial position of damn near every Top 40 signal up & down the east coast, but that was then. Hell, WKBW changed its call to WWKB and for all I know their big thrill at night is Michael Savage or Laura Ingram. I shed a tear when I think of how da'yout of today have been denied the joys of hearing a DJ rip through 40 seconds of copy in :29 flat regarding drag racing, then do a perfect crossfade into the latest from the Four Tops as the words BE THERE echoed into oblivion......... Radio was so much more entertaining back when.

<sigh!>

In any case, if your Philco had a pair you'd be telling me about 5/9 copy on WSM (650) in Nashville or WLW (700) in Cincinnati........... But at least WBZ is a good start.

Now, crank that dial like you mean it!   Undecided
« Last Edit: December 29, 2011, 06:17:29 PM by AC5UP » Logged

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N4NYY
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« Reply #35 on: December 29, 2011, 06:15:31 PM »

Quote
In any case, if your Philco had a pair you'd be telling me about 5/9 copy on WSM (650) in Nashville or WLW (700) in Cincinnati........... But at least WBZ is a good start. Now, crank that dial like you mean it!   Undecided

Hey, I know medium wave DX yields numerous east coast stations fairly easily, but I get excited when it is on a 1950's tube rig instead of my Grundig S350DL. Anyway, I just picked up the Toronto-North Carolina hockey game! 

BTW, I was tuning the metal shaft, and got hit with B+. LOL. I will use the iso !
   
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AC5UP
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« Reply #36 on: December 29, 2011, 06:21:22 PM »

CKLW (800) from Windsor, Ont. was the big beat in the Motor City back when...........

A hot chassis is just God's way of saying WBZ isn't worth pissing yourself over. That, and put a plastic knob on the shaft, Einstein........  Roll Eyes
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N4NYY
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« Reply #37 on: December 29, 2011, 06:42:12 PM »

Did you look at that component from this radio that I cannot identify?
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NB3O
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« Reply #38 on: December 30, 2011, 06:46:32 AM »

'WBZ played Top 40 but was lame in comparison to WABC (770) in NYC..
.. and for a consumer radio 20 kc's of separation is a little tight."

As a kid I never knew about other DX stations (other than WMCA 570) cuz the IMD from WABC 770, WCBS 880 and WNBC 660 was awful in those stupid pentagrids.  Living less than 2 air miles from ABC's tower in Saddle Brook did not help.

Getting a general did not improve things, as Bill W2ONV (SK) was on either 75 or 20 during prime time and running near the same sig strength into my ARC-5 setup.......

I'm still searching for that hot chassis 5 with a 6th tube preselector stage.....any leads?
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