UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post - 6-gang FM stereo tuner heads

regenfreak · 28th Nov 2022, 11:21 pm

It is probably time consuming to draw the blocks. Just quickie, so far I have:

From input:
1. GaAs switch TOI = +45dm (unknown chip, just based on similar)
2. pre-amp unknown IC ((have to dig further)
3. GaAs switch TOI = +50dbm HMC284AM,
4. 20dn attenuator TOI = +44dbm, HMC307
5. LP
6. 1st mixer HMC488 3.1-3.9G, TOI = +15dbm
7. 18db amplifer HMC716 NF = 1.0, TOI = +33dm
8. BF/LPF
9. 2nd mixer HMC488? 3.1-3.9G, TOI = +15dbm
10. 810 MHz saw filter NDF 8027
11. 3rd Mixer ADE-2 mixer TOI = +20dbm

I downloaded the hi res photos in the descriptions of the EEVbllog video so I may try to identify the unknowns.

28th Nov 2022, 11:21 pm	#304
regenfreak Heptode Join Date: Nov 2018 Location: London SW16, UK. Posts: 655	Re: 6-gang FM stereo tuner heads It is probably time consuming to draw the blocks. Just quickie, so far I have: From input: 1. GaAs switch TOI = +45dm (unknown chip, just based on similar) 2. pre-amp unknown IC ((have to dig further) 3. GaAs switch TOI = +50dbm HMC284AM, 4. 20dn attenuator TOI = +44dbm, HMC307 5. LP 6. 1st mixer HMC488 3.1-3.9G, TOI = +15dbm 7. 18db amplifer HMC716 NF = 1.0, TOI = +33dm 8. BF/LPF 9. 2nd mixer HMC488? 3.1-3.9G, TOI = +15dbm 10. 810 MHz saw filter NDF 8027 11. 3rd Mixer ADE-2 mixer TOI = +20dbm I downloaded the hi res photos in the descriptions of the EEVbllog video so I may try to identify the unknowns. Last edited by regenfreak; 28th Nov 2022 at 11:51 pm.