Soviet East German Radio

[Mark Hennessy]

Yes, I share an office with someone who is -3.5. Trying on their glasses was bizarre

I'm one of the younger folk working here. As you might imagine considering the ages and profession, eyesight is something we discuss a lot.

These sorts of things can be corrected for, so there's no excuse for letting them hold you back. Some aren't that fortunate.

[Nowhere-Man]

I actually have an awkward condition called Prosopagnosia. This is an inability to recognise faces or face blindness. Growing up with it was traumatic and bewildering. Now, I can actually see the funny side but for sure you can wind up in highly uncomfortable situations. I mean, normally with the condition, you learn to focus on stuff like glasses, clothes, voice tone and, above all, location and setting. However, I've bumped into people out of location and simply not known who they are. Well, in the case someone says,"Don't you know me?", I may take off my specs, clean the lenses and make the claim I couldn't see that well. It is, however, problematic and people do get offended. I even met one guy online who'd failed to recognise his own parents out of the home.

[Nowhere-Man]

Tonight I battled with one of those mind boggling graphs you often find in ARRL and I figure I'm a bit weak on discrimination and selectivity curves.. So these next few days may require a bit of basic backtracking. As it is, I have a limiter discriminator circuit to ponder. Pretty much the basics of FM modulation I now understand. This is conversion of frequency deviation to amplitudes and detection. However I plan to hammer this whole area each night till it beds in. I have Lawrence's posts too for reference.

[Nowhere-Man]

One thing that came up tonight was opposing fields in transformers. If a primary has 400 turns to 2800 turns secondary and the current in the secondary is 0.2 Amp, what is the primary current? Answer: 1.4. So the currents are inversely proportional to the voltages.

[Murphyv310]

Hey, Trevor, hope you get better. Years ago I nearly died of flu. Honey may help you recover or even garlic. I used to just chop garlic and swallow with orange juice to kill the taste.

Thanks NM.
Actually thought I had a heavy cold but then had a temperature of 102f heart rate of 130 and pain everywhere, doc came in and am on anti viral and antibiotics in high doses, also got a row for not going for the flu jag. Nowhere near right yet, he says at least two weeks perhaps longer.

[Nowhere-Man]

Total rest is required. One of my friends is going for her hospital result today as she collapsed a few weeks ago.. She's only 30. I suspect she was maybe over-working.

[Murphyv310]

Over done it most of my life, got a fright in 2007 but didn't really take too much heed, the bypass of a year ago though has taught me how fragile we really are.
Thanks for the kind comments, hope your friend is OK.

[Nowhere-Man]

Here is a discovery I made tonight I decided to share. It came from something in ARRL where reactance in resonant circuits compared to loads on the circuit is discussed. It states if power dissipated across the load on the resonant circuit (such as a transmitter) is about 10 times as great as the power lost in the inductor and capacitor, then power lost in reactance will be greater overall. So I did the following:
VAC in = 230
XL and XC at resonance = 250 R
Load on circuit (transmitter) = 3000 R
So, 230/250 reactance = current 0.92 amp. To get voltamps I get 211 dissipated power.
Then the load of 3000 watts (real power) I get current = 0.07 amp and watts = 17.6
So the power in the resonant circuit is now BIG.
Here is what gave me a kick: Divide the load wattage into the Voltamp power which is 211/17 and lo and behold 12. And ARRL in their sums gives 12 as the circuit Q.
I think my maths here is correct but, if not, apologies in advance.
Although pointless I admit, I like doing this kind of numbers game.

[Nowhere-Man]

Prior to the dabbling in Q's, I had been studying a Limiter discriminator circuit for narrowband FM. It's on page 329. It would be of interest to Lawrence due to the use of a centre tapped secondary and two induced voltages of different phase on the tapped secondary. It was the phase issue that had me puzzled again. As a starting point I assume any primary and secondary should normally be opposite in phase. Here a capacitor is in circuit to alter the phase.
And finally, if this is of zero interest to anyone, just ignore me. I just find it all a great way to focus the mind rather than vegetate watching TV. Which is now what I'm going to do.

[Crackle]

Bets on if NM is ever going to get his radio repaired.

Mike