1969 vs 1971 Am/FM Stereo Differences ?

[Greg R.]

Can someone explain the differences between a 1969 and a 1971 am/fm stereo radio ? Or are they exactly the same ?

[Joe L.]

Re: 1969 vs 1971 Am/FM Stereo Differences ?

Greg-----

They're, basically, the same. They are the same part number, too. However, I believe that there were some very minor changes such as the font script on the lens and the configuration of the stereo indicator light. Nothing more than that. Later units are pretty close to the same, too. However, they have one very significant difference---the length of the knob shafts. The knobs changed for the 1972 and the shafts changed with them.

[Wayne W.]

Re: 1969 vs 1971 Am/FM Stereo Differences ?

68 and early 69s, were a totally different animal from the 70 and later units. They had the Green Script "Sterio" light in the corner and the add on converter box.

[Reba Whittington]

Re: 1969 vs 1971 Am/FM Stereo Differences ?

According to the judigng guides, 1969 through 1971 radios have block lettering for "stereo." Only 1968 had the script lettering. Of course, there could be some carry over to early '69s. All had the separate convection (is that the correct term?) box behind the dash.

[Wayne W.]

Re: 1969 vs 1971 Am/FM Stereo Differences ?

I think that there was a considerable carry over into 69. I have seen too many. The one with "Sterio" has a totally different converter box that was evidentally built into the unit on the later ones. They all have the dual transistors with the convector.

[Warren F.]

Re: 1969 vs 1971 Am/FM Stereo Differences ?

Greg,
There is also a difference in the balance control knobs that insert into the "well area" of the bezel. 1969 use smaller size balance knobs. 1970 & '71 use a larger balance knob (exactly the same style) that fills this "well" area fully. There is a noticeable gap with the '69 style.

[Joe L.]

Re: 1969 vs 1971 Am/FM Stereo Differences ?

Wayne-----

The U79 radio units used for 1968 through 1971 were all of the same part number-----GM #7303211. Although there were, I believe, some minor changes made to the unit over these years, I think that they are cosmetic only having to do with the lens and stereo indicator light. These changes could have been made by revisions to the drawing for the radio. The fact that the same part number was used for all these years strongly implies that the units are functionally equivalent and interchangeable.

As far as I know, all the 68-76 U-79 radios used an external "adapter". The unit used for 1968 only was GM #7303201. It's possible this unit was also used for early 1969. The 1969 through 1971 U-79 adapter was GM #7311911 for all years.

While the adapter units were different for 1968 and 69-71, the fact that the radios were all of the same part number for the 68-71 period strongly implies that the adapters are interchangeable and that either adapter will work with any 68-71 radio. I don't know that for a fact, of course, but it's hard to imagine that radios of identical part numbers could be enough different that both adapters would not work interchangeably.

[Wayne W.]

Re: 1969 vs 1971 Am/FM Stereo Differences ?

Joe, Anyone that has ever looked at a 68-E69 style radio, will know instantly that it aint the same animal as the later unit. Part number or not they would never be compatable with each other. I am not talking about the transistor unit, but the 68-68 radio has literally what appears to be a add on converter box to make it a sterio. They are physically different. Sometimes numbers dont tell the whole story.

[Joe L.]

Re: 1969 vs 1971 Am/FM Stereo Differences ?

Wayne-----

Where is this "physically different" converter box located? Is it part of the radio head unit or is it seperate from the radio head unit. If it's part of the radio head unit (the part we generally call the "radio"), where is it located on the "radio". The radio unit barely fits in the behind dash space as it is, so I presume you are talking about something located somewhere else.

How is the radio head unit for 1968-E1969 different from the later unit?

[Wayne W.]

Re: 1969 vs 1971 Am/FM Stereo Differences ?

Ok, A picture is worth a thousand words. This is the radio with the green "sterio" indicator.(68-69E) You will notice the big converter box with the two heat sinks for the 501 transistors. The later version with the single dot indicator only had a dual heatsink with no box. This radio is labled Model # 7303211 and the converter is # 7303201

[Joe L.]

Re: 1969 vs 1971 Am/FM Stereo Differences ?

Wayne-----

Thanks fore the picture. It looks just as I expected it would look and the part numbers are just as they should be and as I mentioned previously.

Just to align and define terminology for the rest of this, the box, in GM parlance, is called an "adapter". It is used only with the U-79 stereo radio. The heat sink with the D-501 transistors is called a "convector".

As far as I know, an ADAPTER unit is used with all 68-76 U-79 stereo radios. The unit used for 1969-71 is different than the unit used for 1968, though. So, we're not saying anything different here; that's exactly what I said earlier. It is possible that the 69+ adapter incorporated the convector into the adapter; I'm not sure about that.

As far as the radio head unit goes, the unit you have pictured looks exactly like the 1969-71 unit from what I can see. Also, as you have reported the part number, it's the same as the was used for 69-71. Although it can't be seen in the photo, there are differences in the lens and the stereo indicator light. That was likely handled through a change in the specs for this part number and does not indicate a functional difference in the 68 and 69-71 units. As I said before, I cannot understand, at all, how, if the radio heads are functionally different they could have the same part number.

Just because the external components (i.e. "adapter" and/or "convector")of the 68 and 69-71 are different (and, I agree and have always understood that they are different) does not necessarily mean that they are not interchangeable. It might just indicate a "packaging" difference or some other difference which does not affect functionality. In this regard, do you know that the the 68 "externals" will not function with a 69-71 radio head unit or vice-versa?