Any fans of high fidelity/good sounding table or portable old transistor radios?

[zeno]

I have 2) SR 1 1) SR2 & 1) SR3. Have not found the SR with
a cassette deck yet. GE also made a big radio in the 60's
that had TRF AM & worked great but ate D-cells up.
I only consider AM as I never go FM, its for hippies.
SR1 & 2 about the same SR2 has edge on fidelity.
My SR3 suffers from bad tuning pot & seems to be common
with them. Otherwise its an OK radio but not a 1 or 2.

Most majors in the states made HiFi table radios in the 50's til
mid 60's. None had TRF AM that I remember. Zenith did for years
build a rig with PTO FM tuning but the AM was just a cap tuned
AA5. Fidelity was great but AM just average. I have one of them
also. IIRC those PTO Zeniths & car radios were the only PTO sets
that Joe Six Pack was exposed to.
Fun subject, wish someone would build a real AM radio again.

73 Zeno

[dieseljeep]

Originally Posted by zeno

I have 2) SR 1 1) SR2 & 1) SR3. Have not found the SR with
a cassette deck yet. GE also made a big radio in the 60's
that had TRF AM & worked great but ate D-cells up.
I only consider AM as I never go FM, its for hippies.
SR1 & 2 about the same SR2 has edge on fidelity.
My SR3 suffers from bad tuning pot & seems to be common
with them. Otherwise its an OK radio but not a 1 or 2.

Most majors in the states made HiFi table radios in the 50's til
mid 60's. None had TRF AM that I remember. Zenith did for years
build a rig with PTO FM tuning but the AM was just a cap tuned
AA5. Fidelity was great but AM just average. I have one of them
also. IIRC those PTO Zeniths & car radios were the only PTO sets
that Joe Six Pack was exposed to.
Fun subject, wish someone would build a real AM radio again.

73 Zeno

The Zenith C845 series have a three gang tuning condenser and two stages of AM IF. The seven tube series, didn't have an AM RF stage, or the two IF stages.

[wa2ise]

Originally Posted by wa2ise

]... and the chip died... Went on ebay and ordered some TEA5710 chips from some outfit in China, expect them to arrive around July 15th...

The chips arrived today, and after dealing with a bad soldering iron (it did heat, but not very hot) got the new chip in, and after a couple solder bridges and other stupidity, got it working. The new ceramic filter does have a fair amount of insertion loss (7dB), so AM stations are a little weaker than before, but there's enough AGC to make up for it in the TEA5710.

I decided to replace the loop antenna with a ferrite rod. Removed about 3/4th the turns off the coil to get it to peak on a station near 570KHz. And touched up the trimmer cap for the high end of the band (note the paper sticker identifying the purpose of the trimmers after I did some trial and error. :-)


Here's some characteristics of the ceramic filter. As I mentioned before, this filter came out of a first generation cell phone. Remember the cell phones of the 80's, the ones you could eavesdrop on with a scanner that could tune around 870MHz? Those used narrow band analog FM modulation, and used double conversion IF strips, the 2nd IF was 455KHz but the FM signal required a wideband filter, which I repurposed for wider than usual wideband AM reception. Many narrowband FM radios likely have such filters you could grab for this.

[Sandy G]

Originally Posted by zeno

I have 2) SR 1 1) SR2 & 1) SR3. Have not found the SR with
a cassette deck yet. GE also made a big radio in the 60's
that had TRF AM & worked great but ate D-cells up.
I only consider AM as I never go FM, its for hippies.
SR1 & 2 about the same SR2 has edge on fidelity.
My SR3 suffers from bad tuning pot & seems to be common
with them. Otherwise its an OK radio but not a 1 or 2.

Most majors in the states made HiFi table radios in the 50's til
mid 60's. None had TRF AM that I remember. Zenith did for years
build a rig with PTO FM tuning but the AM was just a cap tuned
AA5. Fidelity was great but AM just average. I have one of them
also. IIRC those PTO Zeniths & car radios were the only PTO sets
that Joe Six Pack was exposed to.
Fun subject, wish someone would build a real AM radio again.

73 Zeno

I have a postwar AM/MW radio, wooden cabinet, that has a PTO. Too lazy to get a ladder & see who made it, but I DO remember it was a rather obscure make I'd never heard of. The PTO didn't seem to offer any real benefits over a std tuning condenser.

[dieseljeep]

Originally Posted by Sandy G

I have a postwar AM/MW radio, wooden cabinet, that has a PTO. Too lazy to get a ladder & see who made it, but I DO remember it was a rather obscure make I'd never heard of. The PTO didn't seem to offer any real benefits over a std tuning condenser.

IIRC, they were using up parts left over from the prewar models. The slug tuned coils eliminated the tuning gang and a separate oscillator and RF coils.
The larger firms like RCA and Philco, didn't use them, but the smaller players did. Admiral, Detrola and Belmont used them, until the supply ran out.
Then they went back to the tuning condenser and the separate coils.

[Sandy G]

Well, ALL my R-3XXs have Permeable Tuning.. Kinda neat to run the R-389's "Motor Tune" gizmo, & watch 'em run up 'n' down.. There MUST be SOME benefit to using it, or Collins, who had Carte Blanche on how they designed & built the R-3xxs, wouldn't have used it..