GrahamH's photos with the keyword: broadcast

IMG 1142

12 Oct 2016 342
A Blaupunkt radio which was my late Father in Law's now held by a Brother in Law. The radio isn't working now but I may get to restore it electronically one day... August 2016.

IMG 1140

12 Oct 2016 346
A Blaupunkt radio which was my late Father in Law's now held by a Brother in Law. The radio isn't working now but I may get to restore it electronically one day... August 2016.

IMG 1139

12 Oct 2016 1 320
A Blaupunkt radio which was my late Father in Law's now held by a Brother in Law. The radio isn't working now but I may get to restore it electronically one day... August 2016.

IMG 1138

12 Oct 2016 2 2 411
A Blaupunkt radio which was my late Father in Law's now held by a Brother in Law. The radio isn't working now but I may get to restore it electronically one day... August 2016.

Earphone radio 1968 009

07 Jan 2013 286
A pocket personal portable AM (no FM at that time) radio which I built in a 36 exp slide box at the start of the 68/69 Christmas school holidays. It was originally built breadboard style with a valve-style tuning capacitor. The circuit has three transistors. The signal path flows from the ferrite rod to the first transistor for RF amplification with regeneration. A diode demodulates the signal which is sent back to the first transistor reflexed as the first AF stage. Two more transistors cascaded give more AF gain. A high impedance crystal earpiece couples the audio to the Listener. Performance was adequate for primary coverage areas. See Notes on 005.

Earphone radio 1968 007

07 Jan 2013 229
A pocket personal portable AM (no FM at that time) radio which I built in a 36 exp slide box at the start of the 68/69 Christmas school holidays. It was originally built breadboard style with a valve-style tuning capacitor. The circuit has three transistors. The signal path flows from the ferrite rod to the first transistor for RF amplification with regeneration. A diode demodulates the signal which is sent back to the first transistor reflexed as the first AF stage. Two more transistors cascaded give more AF gain. A high impedance crystal earpiece couples the audio to the Listener. Performance was adequate for primary coverage areas. See Notes on 005.

Earphone radio 1968 008

07 Jan 2013 255
A pocket personal portable AM (no FM at that time) radio which I built in a 36 exp slide box at the start of the 68/69 Christmas school holidays. It was originally built breadboard style with a valve-style tuning capacitor. The circuit has three transistors. The signal path flows from the ferrite rod to the first transistor for RF amplification with regeneration. A diode demodulates the signal which is sent back to the first transistor reflexed as the first AF stage. Two more transistors cascaded give more AF gain. A high impedance crystal earpiece couples the audio to the Listener. Performance was adequate for primary coverage areas. See Notes on 005.

Earphone radio 1968

07 Jan 2013 1 324
A pocket personal portable AM (no FM at that time) radio which I built in a 36 exp Kodak slide box at the start of the 68/69 Christmas school holidays. It was originally built breadboard style with a valve-style tuning capacitor. The circuit has three transistors. The signal path flows from the ferrite rod to the first transistor for RF amplification with regeneration. A diode demodulates the signal which is sent back to the first transistor reflexed as the first AF stage. Two more transistors cascaded give more AF gain. A high impedance crystal earpiece couples the audio to the Listener. Performance was adequate for primary coverage areas. See Notes on 005. An oldie added to kick off the Macgyverering group. Using a 36 exp Kodak slide box as a radio case.

Earphone radio 1968 006

07 Jan 2013 219
A pocket personal portable AM (no FM at that time) radio which I built in a 36 exp slide box at the start of the 68/69 Christmas school holidays. It was originally built breadboard style with a valve-style tuning capacitor. The circuit has three transistors. The signal path flows from the ferrite rod to the first transistor for RF amplification with regeneration. A diode demodulates the signal which is sent back to the first transistor reflexed as the first AF stage. Two more transistors cascaded give more AF gain. A high impedance crystal earpiece couples the audio to the Listener. Performance was adequate for primary coverage areas. See Notes on 005.

Earphone radio 1968 005

07 Jan 2013 1 338
A pocket personal portable AM (no FM at that time) radio which I built in a Kodak 36 exp slide box at the start of the 68/69 Christmas school holidays. It was originally built breadboard style with a valve-style tuning capacitor. The circuit has three transistors. The signal path flows from the ferrite rod to the first transistor for RF amplification with regeneration. A diode demodulates the signal which is sent back to the first transistor reflexed as the first AF stage. Two more transistors cascaded give more AF gain. A high impedance crystal earpiece couples the audio to the Listener. Performance was good for primary coverage areas.

Earphone radio 1968 003

07 Jan 2013 237
A pocket personal portable AM (no FM at that time) radio which I built in a 36 exp slide box at the start of the 68/69 Christmas school holidays. It was originally built breadboard style with a valve-style tuning capacitor. The circuit has three transistors. The signal path flows from the ferrite rod to the first transistor for RF amplification with regeneration. A diode demodulates the signal which is sent back to the first transistor reflexed as the first AF stage. Two more transistors cascaded give more AF gain. A high impedance crystal earpiece couples the audio to the Listener. Performance was adequate for primary coverage areas. See Notes on 005.