09-05-2018, 04:18 AM
I have a recollection that when the Hacker Mayflower was discussed on UKVRR, it came out that Hacker had used proprietary front ends, but different types for the RV14 and RV20 models, hence the difference in their tuning ranges. One of them might have been a Görler model.
I imagine that cost considerations dictated that a bought-in front end be used, and that may have limited the choice to the single-valve type. I am not aware that the UK and European front end makers generally offered two-valve types as, although there might have been one or two. Where two-valve front ends were used on receivers and tuners, I think that they were mostly in-house units, sometimes integrated into the main chassis.
Re the ECC88 substitution, did any of the setmakers use this valve as original equipment in a single-valve FM front end? It was used as a cascode RF amplifier – its primary VHF purpose – in the Leak Troughline Stereo, in that case superseding the ECC84 that had been used in the Troughline II and 3. But I don’t think that I have ever seen it used in a single-valve FM front end application. The European setmakers seemed happy to stay with the ECC85. In the USA the 6JK8 was developed as an improved FM valve. It had a frame-grid RF amplifier, but a conventional oscillator-mixer. That shows that for the RF amplifier at least, a frame-grid valve was seen as being beneficial. That valve arrived at about the same time as FM stereo broadcasting, which would have created a needed for improved front end performance.
Cheers,
Steve
I imagine that cost considerations dictated that a bought-in front end be used, and that may have limited the choice to the single-valve type. I am not aware that the UK and European front end makers generally offered two-valve types as, although there might have been one or two. Where two-valve front ends were used on receivers and tuners, I think that they were mostly in-house units, sometimes integrated into the main chassis.
Re the ECC88 substitution, did any of the setmakers use this valve as original equipment in a single-valve FM front end? It was used as a cascode RF amplifier – its primary VHF purpose – in the Leak Troughline Stereo, in that case superseding the ECC84 that had been used in the Troughline II and 3. But I don’t think that I have ever seen it used in a single-valve FM front end application. The European setmakers seemed happy to stay with the ECC85. In the USA the 6JK8 was developed as an improved FM valve. It had a frame-grid RF amplifier, but a conventional oscillator-mixer. That shows that for the RF amplifier at least, a frame-grid valve was seen as being beneficial. That valve arrived at about the same time as FM stereo broadcasting, which would have created a needed for improved front end performance.
Cheers,
Steve
