SuperradioII vs SuperradioIII

[cspence]

I just bought a gently used SRIII since they're out of production. I did a side by side comparison today and its clearly no equal to tne SRII . The selectivity is poor at best. I live about 15 miles from WCBS an it splashes all over from about 830 to 910khz. No sign 910 in Rockland County or 850 on Conn. Last week there was a new in the box SuperradioII on Ebay that finished at over $200.oo

 

[rbrucecarter5]

I just bought a gently used SRIII since they're out of production. I did a side by side comparison today and its clearly no equal to tne SRII . The selectivity is poor at best. I live about 15 miles from WCBS an it splashes all over from about 830 to 910khz. No sign 910 in Rockland County or 850 on Conn. Last week there was a new in the box SuperradioII on Ebay that finished at over $200.oo

There are fixes and modifications that boost the selectivity - but the biggest problem is leakage through all those transistor switches associated with the wide bandwidth setting. Get rid of them all, the selectivity is great.

The "1" is the most selective of the three models - I can eliminate all third adjcent IBOC splatter, and it is not too bad even on second adjacents. I can null the IBOC sidebands and hear distant stations just fine. Nothing helps the first adjacents, though.

 

[OKCRadioGuy]

Any of you guys try a super tuner IV? It is much more selective than a III ever thought about being. With that being said I hear the IIID is a better deal but I havent tried it myself. I do know that the new Delco radios are the best thing I have ever had. I can hear the HD hiss on adjacents to the locals even with mine. Absolutely amazing radios!

 

[skippertthomas]

I'll take a Supertuner II and a half, please....

 

[pqgeorge]

I just bought a gently used SRIII since they're out of production. I did a side by side comparison today and its clearly no equal to tne SRII . The selectivity is poor at best. I live about 15 miles from WCBS an it splashes all over from about 830 to 910khz. No sign 910 in Rockland County or 850 on Conn. Last week there was a new in the box SuperradioII on Ebay that finished at over $200.oo

The SRIII is no match for the SRII. Production quality on the SRIII really suffered, right from the get go. Back in early 90's, I noticed from the moment I opened the box and fired up the SRIII, that something was radically wrong. The radio had a strong noise floor on both AM and FM. I was told by another engineer friend to simply reverse the speaker leads (reverse the polarity). You know something? It worked! Apparently, many of the SRIII radios that came off the assembly line had the same problem. The FM side was numb as hell. Very un-selective and I didn't even bother to change the IF filters to 110's. The AM was so-so. Very selective but it drifted after a few minutes and was very numb above 1600. And when the batteries began to go down, ....so did the frequency.

However, about 5 years ago, I was able to acquire a used SRII at an antique store for (and get this....) $10.00 US. I knew what it was, but the dealer had no idea what it was worth. So, I bought it. I cleaned it up to practically brand new condition. Replaced the broken FM antenna and replaced the IF filters. I still use it daily. It so stingy on batteries that I only replace them once every three months. And I use cheap Panasonic batteries, available at $1.00 US for a pack of 4. (The radio takes 6.).

The SRIII left a lot to be desired. And I was a big GE Super Radio fan since the 80's.


Peter Q. George (K1XRB)
Whitman, Massachusetts

 

[rbrucecarter5]

Any of you guys try a super tuner IV? It is much more selective than a III ever thought about being. With that being said I hear the IIID is a better deal but I havent tried it myself. I do know that the new Delco radios are the best thing I have ever had. I can hear the HD hiss on adjacents to the locals even with mine. Absolutely amazing radios!

Two topics here - Pioneer car radios and GE portables.

The Pioneer Supertuner 4 was fairly short lived, mainly in GM outline radios. The 3D is the current production, and is light years better than the 3. The 3D takes advantage of adaptive IF technology for incredible selectivity (first adjacents next to strong locals with no crosstalk). Mine is the 5900i. The 4900i - NOT supertuner 3D. 5900i IS supertuner 3D. Read the descriptions CAREFULLY.

 

[rbrucecarter5]

The SRIII is no match for the SRII. Production quality on the SRIII really suffered, right from the get go. Back in early 90's, I noticed from the moment I opened the box and fired up the SRIII, that something was radically wrong. The radio had a strong noise floor on both AM and FM. I was told by another engineer friend to simply reverse the speaker leads (reverse the polarity). You know something? It worked! Apparently, many of the SRIII radios that came off the assembly line had the same problem. The FM side was numb as hell. Very un-selective and I didn't even bother to change the IF filters to 110's. The AM was so-so. Very selective but it drifted after a few minutes and was very numb above 1600. And when the batteries began to go down, ....so did the frequency.

However, about 5 years ago, I was able to acquire a used SRII at an antique store for (and get this....) $10.00 US. I knew what it was, but the dealer had no idea what it was worth. So, I bought it. I cleaned it up to practically brand new condition. Replaced the broken FM antenna and replaced the IF filters. I still use it daily. It so stingy on batteries that I only replace them once every three months. And I use cheap Panasonic batteries, available at $1.00 US for a pack of 4. (The radio takes 6.).

The SRIII left a lot to be desired. And I was a big GE Super Radio fan since the 80's.


Peter Q. George (K1XRB)
Whitman, Massachusetts

The SR 3B has an IC in the FM front end, the 3A is discrete. The 3A and 3B have high noise floors in random units - there is a transistor or two that is incorrectly biased. I have a fix for it.

The 3B FM sensitivity is better, probably the IC does the job right. I've made a 3A get FM stations up to 120 miles with the whip, though, after the filter mod. hook either up to an antenna, and they are little DX tuners.

If you have a SR3 where the frequency drifts with weak batteries, the DC-DC converter either needs re-tuning or is defective. The IC it uses to convert 9V to 15V is rock stable all the way down to an input voltage of 4.5V. Probably, you are having a manifestation of the defective tuning pot that killed the product. I have a fix for that as well - I replace the 300k pot with a 500 k, and trim the resistance down close to 300k with resistors in parallel. NOT the most linear or accurate dial after that, but stability is worth it.

The SR3 is virtually the same design as the 1 and 2 - all use the same IC for the heart of the radio. The biggest difference from 2 to 3 was the change from tuning cap to varactors - which caused a few inductors to change to accomodate DC coupling to varactors. Other than that, the schematics are the same even down to the reference designators. The 3 also put in lots of transistor switches on AM to lower the Q for wideband reception. Personally - I'd dike them all out to get the selectivity back - leakage through that many transistors lowers the Q even on narrowband. Another change from the 2 to the 3 was to take full advantage of the differential audio amp in the IC to quadruple the output power. The 1's and 2's used it single ended. Although I think the sound on the older radios is actually better. The 3 should be easier on batteries because of this, because it more efficiently amplifies the audio train. Poor battery life may be related to the DC / DC being off - that could cause it to drink power as it works overly hard to produce what should be only a few mA of tuning voltage at most.