05-20-2011, 09:44 AM
Hi all,
I have often wondered whether anyone has compared the performance of the code 121 chassis against the code 125 chassis of this model or even the 37-116 code 121? I know that it is commonly believed (and I agree) that Philco cut some corners on the rf deck of the code 125 chassis, since there are about a dozen compensator's left out of the code 125 chassis.
I have a code 121 chassis here and also a code 125 chassis neither of which has been restored as of yet. But, after looking at them closely, I discovered something which is very clear on the schematics but which I had failed to notice previously. That is, the codel 121 chassis all use a three gang single section tuning condenser. All of the code 125 chassis use a three gang dual section tuning condenser. I don't think I have seen this style of tuning condenser used in consumer grade radios before. I have seen them many times in communication receivers. I also noticed that the code 125 chassis use a different coil set and a differently calibrated tuning dial. It would seem that the proper 'Q' and possible dial tracking would be easier to achieve with the smaller tuning condenser used on the higher bands.
So, this latest discovery has peaked my curiosity. I wonder if there is actually a difference in performance between the two chassis? Or could it be that the Philco engineers discovered a better way to accomplish the same task? It would seem that if their primary interest was to save money, that they would not have increased costs by using a much more expensive tuning condenser in the set. Furthermore, I noticed that the number of adjustments on the broadcast band is the same in both chassis. It is only on the higher bands that the code 121 chassis have all the additional adjustments. It appears as if the additional compensators were added to try and get the radio to track properly across the band. Maybe with a dual section tuning condenser and a different coil set, the additional compensators were not needed? I don't know?
I'm just posting this for discussion if anyone cares to comment or offer an opinion.
Best regards,
Ed
I have often wondered whether anyone has compared the performance of the code 121 chassis against the code 125 chassis of this model or even the 37-116 code 121? I know that it is commonly believed (and I agree) that Philco cut some corners on the rf deck of the code 125 chassis, since there are about a dozen compensator's left out of the code 125 chassis.
I have a code 121 chassis here and also a code 125 chassis neither of which has been restored as of yet. But, after looking at them closely, I discovered something which is very clear on the schematics but which I had failed to notice previously. That is, the codel 121 chassis all use a three gang single section tuning condenser. All of the code 125 chassis use a three gang dual section tuning condenser. I don't think I have seen this style of tuning condenser used in consumer grade radios before. I have seen them many times in communication receivers. I also noticed that the code 125 chassis use a different coil set and a differently calibrated tuning dial. It would seem that the proper 'Q' and possible dial tracking would be easier to achieve with the smaller tuning condenser used on the higher bands.
So, this latest discovery has peaked my curiosity. I wonder if there is actually a difference in performance between the two chassis? Or could it be that the Philco engineers discovered a better way to accomplish the same task? It would seem that if their primary interest was to save money, that they would not have increased costs by using a much more expensive tuning condenser in the set. Furthermore, I noticed that the number of adjustments on the broadcast band is the same in both chassis. It is only on the higher bands that the code 121 chassis have all the additional adjustments. It appears as if the additional compensators were added to try and get the radio to track properly across the band. Maybe with a dual section tuning condenser and a different coil set, the additional compensators were not needed? I don't know?
I'm just posting this for discussion if anyone cares to comment or offer an opinion.
Best regards,
Ed
