2018-10-07 Air Band Radio Kit HMOOABRA_4.3 Part 3

From FB group Building Transistor Radios comment 2018-10-07

Bob Johansen
I don’t have a way of calibrating an RF signal level. Back when I worked on Aircraft radios we had General Radio VHF signal generators, attenuators and RF signal strength meters and a Panoramic spectrum analyzer. This would have been a piece of cake to t/s. Right now I’m thinking about unsoldering the NE612 and putting the socket in, and borrowing the NE602 from the Vectronics kit I built last month. I’m getting good sensitivity at the pin 4, IF output of the NE, but not good sensitivity at the RF input to the Q1 RF amp. All the voltages look normal at Q1. I may pull out the parts and Q1, I think I have all of them on hand, even a 2SC3355. I’ve been occupied with some other real life things that have priority right now.

3 Responses

  1. RIMBAU GERARD says:

    je n’ai pas le schemas electronique de cette version ni la liste des composants


  2. Andrew says:

    I had similar symptoms – low sensitivity, I found that the IF transformer is tuning flat, I desoldered the R8 resistor, sensitivity increased significantly, try it.

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