About Radio ... Part 8 Intermediate Frequency by Andy Davies.

In this eighth video 'About Radio' I talk about the how the wavelength of the frequencies received by the GEC BC5645 vary from around ten feet to over a mile in length and I talk about how the problem is over come by the introduction of an intermediate or 'I.F.' frequency. This is of course only part of the solution; the rest will come in later videos.
If this helps you please let me know.
Kind regards ... Andy gw0jxm
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In this series of 'About Radio' I want to show you a circuit diagram for a radio and talk you through what each component is there for.

There may be one or two anecdotes along the way, please feel free to let me know the funny radio type things that you've seen and done.


I haven't uploaded the next video yet but when I do I'll give you the link details here.

Here's the full link to 'About Radio ... Part 1 by Andy Davies'
   • About Radio ... part 1  Removing the ...  

Here's the full link to 'About Radio ... Part 1 by Andy Davies'
   • About Radio ... part 1  Removing the ...  

Here's the full link to 'About Radio ... Part 2 by Andy Davies'    • About Radio ... Part 2 Data sheet and...  

Here's the full link to 'About Radio ... Part 3 by Andy Davies'    • About Radio ... Part 3 HT smoothing b...  
HD Link to part 3    • About Radio ... Part 3 HT smoothing b...  

Here's the full link to 'About Radio ... Part 4 by Andy Davies'
   • About Radio ... Part 4  AC ripple on ...  
HD link to part 4    • About Radio ... Part 4  AC ripple on ...  

Here's the full link to 'About Radio ... Part 5 by Andy Davies'
   • About Radio ... Part 5  VHF input sta...  
HD link to part 5    • About Radio ... Part 5  VHF input sta...  

Here's the full link to 'About Radio ... Part 6 by Andy Davies'
   • About Radio ... Part 6  Grid bias & t...  
HD link to part 6    • About Radio ... Part 6  Grid bias & t...  

Here's the full link to 'About Radio ... Part 7 by Andy Davies'
   • About Radio ... Part 7  A closer look...  
HD link to part 7    • About Radio ... Part 7  A closer look...  

If you're interested in this series of videos then I recommend that you also take a look at Rick McWhorter's channel.
This is the full link to one of the videos by Rick McWhorter
   • The Vacuum Tube Shortwave Radio  
(AllAmericanFiveRadio) Do download his book, it's free but the information is priceless! Rick has put a huge amount of effort and a lifetimes worth of experiences into his videos, I think you find them interesting and entertaining, but be warned, you'll get hooked! I have.



In my videos, inevitably there will be things that I forget to mention and maybe some things I get wrong, please feel free to comment and put me right if I go wrong.

It's some 40 odd years since I was involved with domestic radios, that was before I qualified as an electrician and subsequently moved on into high power high frequency electronic engineering.

I'm not setting out to tell you how to repair radios, the fact that you've read this far probably means you're Interested in radio and I'm merely helping to confirm what you already know.

With regards to safety, when I was training they told me that if 30 milliamps passes through you for 30 milliseconds can kill you.

Don't make the mistake that thinking that an isolation transformer will protect you from being electrocuted.

An isolation transformer, correctly installed, will only protect you from passing current from the mains electrical supply to earth, that's all.

If you get across the HT AC or the HT DC that is the High Tension Alternating Current or High Tension Direct Current supply of the radio and the conditions are right, it will stop your heart and if there's no one around to start it again it might just stay stopped!

Do use an isolation transformer but back that up with good safe working practice.

I'm not setting out to teach you good working practice but do be aware volt for volt DC is more likely to stop your heart than AC but I can also tell you that both hurt and both can kill!