>The following story is true. It is mentioned here because it may be
>relevant to why people believe low Q parasitic suppressors are the leading
>protectors from amplifier destruction. It is a war story, so it may be of
>interest to those who like to hear them. It is also a radio story of a ham
>operator.
>
>During WWII, a German U-Boat was based in Singapore. Prior to leaving, a
>German SS agent came aboard for an unspecified reason, wearing a suit and
>carrying a black umbrella. Immediately, a buzz began aboard the submarine,
>because submariners were superstitious by nature (with good reason, 95% of
>them did not return) and black umbrellas were very unlucky. From the start,
>this mission was in great danger, according to the majority of the crew.
>The skipper, Heinrich Pahls, was not superstitious and ignored the crew.
>After being out to sea for some time, it became necessary to refuel. Their
>assigned refuel was in the Indian Ocean. They were #7 and last on the list
>to be refueled. Because the Allies was searching everywhere, Henry stayed
>submerged during the day and surfaced at night. All the others were finally
>refueled and left. Then, the refueling ship was spotted and sunk, with no
>other ships nearby and Henry left with almost no fuel.
>
>According to protocol, Henry was simply to remain there and check into the
>German net at Singapore at the assigned time and frequency. For three days,
>he tried to do that. However, communications was never established. After
>a couple of days, the German Navy assumed he was sunk and simply forgot
>about the submarine and crew. Things were getting desperate, and the crew
>grumbled even more that the black umbrella was the problem. However, Henry
>had been an amateur radio operator in high school back in Germany and
>remembered the formula for antennas. He calculated the length of an
>inverted vee antenna and found things to make it, supported by the
>periscope.
>
>At the next time Singapore was on the air, Henry had the inverted vee
>connected. He was standing on deck waiting for word from the radio
>operator. Suddenly, a crew member burst onto the deck with the SS agents
>black umbrella. He opened it and the wind carried it off. It was seconds
>later that the radio officer yelled that radio contact was made with
>Singapore. The crew cheered. All the crew members, except for Henry,
>"knew" releasing the black umbrella was the reason for contact with
>Singapore. Henry did not charge the sailor who stole the umbrella, and in
>fact told the SS agent that he did not recognize who it was. If you asked
>the sailors, probably 95% or better would have assured you it was releasing
>the black umbrella that saved the ship.
>
>Fuel did come.
** Excellent.
>Heinrich Pahls survived and came to the United States,
>becoming K7MMK. He died peacefully last year due to old age. He told me
>this story, and others, while sailing in various spots around the world as
>we did on many occasions.
>
>I mention this story, because using nichrome wire in parasitic suppressors
>may be similar to getting rid of the black umbrella.
>
** ... assuming that AC circuit analysis does not apply to VHF
suppressors and that resistance-wire has less R as frequency increases.
cheers, Colin
- R. L. Measures, a.k.a. Rich..., 805.386.3734, AG6K,
www.vcnet.com/measures.
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