diytube.com

How much do you think one of those will fetch NOS?

I was bored and surfing the 1967 Radio Shack catalog and it cost $2.39 then, about $16.17, according to the CPI in today's money.

Also, do you think it would hold up in a stereo 70 like the Mullards? After all, they were "guaranteed for life."

It depends on who really made it. Somewhere around here I have a Realistic Lifetime 5AR4. It is silkscreened "GE" on the base, but etched "GT BRITAIN" with Mullard codes on the glass. Go figure.

Back in the 1950s and 1960s, the US Dollar was strong, and most European currency was relatively "weak", and the Mullards, Telefunkens and Amperex tubes were generally considered as being the "cheap imports" at the time.

These tubes were often supplied with kits at the time, as they cost less than their US counterparts. Little did they know....

FWIW, some of the Radio Shack "Lifetime" 12AX7s were Telefunkens, they have the little tell-tale "diamond" embossed on the base.

Radio Shack just chose replacement or equivalent tubes which cost them the least, and the same tube type may have more than one country of origin, from year to year.

/ed B

The same catalog offered for sale the Realistic SAF-40D with a matched tuner that boasted:

70 watts of undistorted power, large output transformers give clear and resonate bass!

http://www.radioshackcatalogs.com/catalogs/1967/

go to page 32-33

After some research I found that amp uses 5 12AX7's and the output tubes use 7189's. I think those are like EL84s, a tube which I do not know much about. The OPTs seem a little beefy for what I have seen in similar amps but 35 watts seems a little much for UL mode. It would seem to me that they are running in pentode mode cathode biased.. You agree? If so, id imagine that would be distortion city.

http://www.radiomuseum.org/r/radio_shac ... saf40.html

You can get about 17 watts out of a EL84. You should be able to get a little more out of a 7189, because of higher plate voltage, but the only way to get 70 watts is to include a 40 watt table lamp.

Back in 1967 they used the "Music Power" of amps, which was
double the real power. So "70 watts" was 35 watts per channel x 2.
Which is really 17 watts x 4 ... at least back then no one cheated,
they all used the same ratings.

Car stereo and computer speakers and other audio items are
still not forced to comply to that. That's why you see
computer speakers powered by a 300 ma wall wart claiming
to be "400 watts" ... car stereo amps are "1000 watts" haha

If a car stereo were to supply 1000 watts, id think you would need a bigger battery or more than one, depending on the battery and alternator!

Go to page 47. The Mullard EL-34MP went for $6.89 in 67'. That would be $46.61 in today's money. Today's pairs vary but are fairly comparably prices, maybe a little cheaper for most pairs.

How come the shack did not carry 6550's. Too expensive?

quote:
If a car stereo were to supply 1000 watts, id think you would need a bigger battery or more than one, depending on the battery and alternator!

Over 20yrs ago when working bench repair we tested an Alpine power amplifier that was the biggest out at the time. To make a long story short it didn't come close to its rated power with one battery, five batteries or 10 batteries with a 250Amp charger on boost. Its all hype and some believe in it.

Radio Shack carried "receiving" tubes, but the 6550 has always been considered an industrial tube. Yes, it's in the RCA receiving tube manual, but just like the 7591, RCA was virtually shamed into listing these non-RCA tubes in their final printing of the manual, due to the tremendous popularity of them.

Dave

You can take that lifetime Radio Shack tube to a Rat Shack when it fails and get a new replacement (without the lifetime warranty). Its pretty funny actually, because when you go into the store, the guy at the desk doesn't even know what a vacuum tube is and will have to call a manager, or in my case, call the district office. Eventually they decide that yes there is a warranty that they have to honor, so then ended up sending me a JJ 6L6 to replace the bad Rat Shack 6L6 I had, and that I had picked up at a local surplus seller for $2! It was worth the time waiting for the people there to get a clue...haha.

Greg

I've seen anecdotal evidence that "The Shack" as they are now calling themselves (presumably because nobody knows what a radio is anymore) does, or did, maintain stock of vacuum tubes at a warehouse location in Texas. I've come across several stories of smartass tube guys wading thru zit faced store clerks up through management hierarchy to eventually be sent a NOS replacement on the grounds that the new tube does not carry the "Lifetime" warranty of it's predecessor and that no further replacements will be given.

Up to recently, RS used to have a "partnership" with AES, to supply the "Lifetime" tube replacements. Apparently this is no longer the case.

The "Shack" just barely sells comoponents parts anymore Just becoming yet another consumer (disposable) goods vendor.

They're just slowly pushing themselves to the edge of the cliff...

The Shack, becoming more like "The Shanty"

/ed B

EWBrown,

I am very disappointed with the shack as well

I remember when i was a child going into a shack and in the back of the store seeing all those nice component parts. It probably helped fuel my electronics interest, subconsciously perhaps. Now when I go into a shack just to buy a few diodes, the zit faced clerk asks me about my stupid cellphone

There was an old timer manager in one of the local radio shacks in Evanston who actually had a working knowledge of electronics, perhaps an engineer or a serious hobbyist himself! When I was in high school, I frequented that place and remember him complaining about the direction Radio Shack was heading. Where are those guys now?

EWBrown wrote:They're just slowly pushing themselves to the edge of the cliff...

Indeed!

They did this some years back in Canada, but it worked to our advantage.... they dumped all their parts stock on Liquidation World and we picked up the parts for a penny or two on the dollar

Cheers!