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Amateur Radio Quiz: Vintage Radios -- Such a Bargain!

05/15/2013

By H. Ward Silver, N0AX
n0ax@arrl.net

Who can resist taking a long look at the vintage veterans sitting along the aisles of the flea markets? Hey, I’m talking about the radios, not the attendees! “Big iron” is making its comeback with Johnsons and Hallicrafters and Swans shoulder-to-shoulder at the hamfests. Before you test your lumbar regions by lugging one home, you might want to exercise your antique assessment skills first!

1) Which of these is most likely to need replacement in a vintage radio?
a. Dial cord
b. Dial lights
c. Bypass capacitors
d. Power cord

2) Which company manufactured the “lunchbox” radios?
a. Gonset
b. Drake
c. Johnson
d. Heathkit

3) Which company proclaimed “the quality goes in before the name goes on?”
a. McMurdo-Silver
b. Zenith
c. RCA
d. Magnavox

4) Why are sweep tubes generally held in low regard as ham-band final amplifiers?
a. They run too hot.
b. They are expensive.
c. They were only good for video signals.
d. They often create excessive distortion products if not run linearly.

5) What is the meaning of “NOS?”
a. New old stock
b. Not often salvageable
c. Never on Sunday
d. Needs operating savvy

6) A “swinging link” was found in what part of vintage radios?
a. Balanced feed line outputs
b. Crystal oscillator tuning
c. Receiver interstage selectivity
d. Grounding chains

7) What did a “Q multiplier” do?
a. Increased sensitivity
b. Decreased VFO warm-up time
c. Increased selectivity
d. Decreased loss in transmitter output circuits

8) Which of these accessories was likely to be “high-Z?”
a. Keying circuit
b. Headphones
c. Rectifier output
d. Cathode follower output

9) Which of these tubes was a very popular transmitter “final” still in use today?
a. OC4
b. 5996
c. 6146
d. 5U4

10) Mercury vapor was used in what vintage component?
a. Thermal cutoffs
b. Rectifier tubes
c. Grid leaks
d. Q36 modulators

Bonus Question: Why do you smell a vintage radio?

Answers:
1. c -- The wax-and-paper versions are usually goners if they haven’t already been replaced.
2. d -- The “Twoer,” “Sixer” and “Tener” put a lot of budget-minded hams on the VHF bands.
3. b -- Transoceanics are perhaps the best known of Zenith’s shortwave all-band receivers.
4. a -- But they were cheap!
5. a -- NOS refers to tubes and components that are still in their original shipping boxes.
6. a -- A swinging link is a technique used for coupling single-ended transmitter outputs to balanced feed lines.
7. c -- Q multipliers reduced the bandwidth of the IF stage to which it was attached.
8. b -- High-impedance headphones were used to avoid loading audio outputs.
9. c -- The 6146 was the most popular transmitter output tube for years -- and is still available.
10. b -- The purple glow and flicker lent a certain mystery to power supply operation.
Bonus Answer: To see if anything has burned up! The scent of toasted transformer is particularly troublesome.

 



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