[Collins] 51J4 vs 75A3?

[Jim Brannigan]

The 75A3 is an 75A2 AM radio with a mechanical filter module.
The mechanical filter modification was not well thought out.  The filter and 
additional IF amplifier upset the gain balance of the radio and introduced a 
lot of IF noise.
I tried all manner of mixer changes and product detectors in my 75A3.  There 
was no changing that sows ear into a silk purse.

The 75A4 and S-line receivers were completely new designs.

Jim


>> So I've begun to think about replacing the 51J4 with an amateur band 
>> receiver such as the 75A3.  Why not the A4 you might ask? Well, I really 
>> prefer the cabinet arrangement and style of the J4/A3 models better. For 
>> me its strictly an asthetics issue.
>>
>> So I was wondering what folks on the list thought of using a 74A3 with a 
>> product detector mod? I know one main difference (besides the general/ham 
>> bands) is that the A3 has only 2 mech filters, whereas the J4 has 3. I 
>> should point out that I only own 2 filters for my J4 so in a strict 
>> comparison, I wouldn't be losing anything on that front.