Two Transistor Radio

[Deleted User 16378]

I remember back in the 60’s we had the two transistor pocket radio, if I can remember these of course were cheaper than the six or eight transistor radio. Does anyone know why these were manufactured? I had someone tell me it had to do to a tax or tariff issue that Japan had to pay for radios that had 3 or more transistors in the radios circuit. Also, if I remember the reception performance on the few two transistor radios that I had when I was a child were terrible, the radio only would receive 3 or 4 AM stations here in the Detroit area.

[Ben Zonia]

I suspect that the two transistor radios were TRF, not superheterodyne. So they didn't need an oscillator, mixer, IF stages with amplification and transformers, just a tuned circuit and a diode. Just maybe an RF Amplifier transistor to bring up the signal level of the ferrite loopstick (some had telescoping whips also), and an AF Amplifier transistor. I remember kids in elementary school bringing them in for show and tell after the Holidays.

It was a Nakashuma....

https://www.google.com/search?client=sa ... cz_18,st:0

[Deleted User 16378]

I suspect that the two transistor radios were TRF, not superheterodyne. So they didn't need an oscillator, mixer, IF stages with amplification and transformers, just a tuned circuit and a diode. Just maybe an RF amplifier transistor to bring up the signal level of the ferrite lipstick (some had telescoping whips also), and an AF Amplifier transistor. I remember kids in elementary school bringing them in for show and tell after the Holidays.

I do remember the telescoping antenna on a few pocket AM radios. The two transistor radio definitely had the “kids market” many novelty type radios were sold in that era. Also, we can’t forget that plastic blue crystal radio that every kid owned that had an interest in radio.

[Ben Zonia]

Google "Nakashuma". It was actually a real brand. I thought Allan Sherman made it up. They have pictures of the Mark 2 and Mark 3, and one picture has the leatherette case with holes in it. No Mark 4 though, the one he said he got. Most of the Nakashuma pictures show radios that look like they're tuned to "The Big 89".

Allan Sherman had three #1 Albums, and was nominated for a Grammy!

[Ben Zonia]

Here's one schematic. Not sure if the Nakashuma models were like this. The first transistor is also the detector, and perhaps a preamp, connected to a variable resistor/potentiometer that controlled the volume.

https://www.electroschematics.com/2-tra ... -receiver/

[Ben Zonia]

More pictures.

https://www.flickr.com/photos/51764518@ ... 176223249/

[Ben Zonia]

I remember back in the 60’s we had the two transistor pocket radio, if I can remember these of course were cheaper than the six or eight transistor radio. Does anyone know why these were manufactured? I had someone tell me it had to do to a tax or tariff issue that Japan had to pay for radios that had 3 or more transistors in the radios circuit. Also, if I remember the reception performance on the few two transistor radios that I had when I was a child were terrible, the radio only would receive 3 or 4 AM stations here in the Detroit area.

What stations could you get on it and what location(s)?

WJR in most locations probably. WJBK wasn't 50000 watts until around 1967. CKLW and WKMH/WKNR would be very location sensitive, East Side vs. West Side. CKLW was probably difficult being just 40 kHz away. If you lived near Royal Oak and Southfield, WWJ and WXYZ would probably have come in. WCAR 1130 was way down in Gibraltar, 50000 watts, but just two towers limit it in the further North parts. If you were really close, WJLB and WEXL.

[Deleted User 16378]

I remember back in the 60’s we had the two transistor pocket radio, if I can remember these of course were cheaper than the six or eight transistor radio. Does anyone know why these were manufactured? I had someone tell me it had to do to a tax or tariff issue that Japan had to pay for radios that had 3 or more transistors in the radios circuit. Also, if I remember the reception performance on the few two transistor radios that I had when I was a child were terrible, the radio only would receive 3 or 4 AM stations here in the Detroit area.

What stations could you get on it and what location(s)?

WJR in most locations probably. WJBK wasn't 50000 watts until around 1967. CKLW and WKMH/WKNR would be very location sensitive, East Side vs. West Side. CKLW was probably difficult being just 40 kHz away. If you lived near Royal Oak and Southfield, WWJ and WXYZ would probably have come in. WCAR 1130 was way down in Gibraltar, 50000 watts, but just two towers limit it in the further North parts. If you were really close, WJLB and WEXL.

When I lived in Roseville the stations I could remember that I could receive were WJR, CKLW, WWJ and WCAR (1130). When I Lived in Southgate, I was able to receive WJR, CKLW, WWJ, WCAR (1130), WKNR (1310) daytime only and WJBK (1500). I could actually see the 12 WJBK towers from my house along with WJR’s tower on Sibley Road and also the WKNR 6 tower array in Allen Park at night with the red tower lights. This was with the two transistor radio.

[paul8539]

You only really needed 2 transistors. The 8 transistor radios supposedly had 6 of them wired in a diode configuration.