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WWII HF communications reliability question

Discussion in 'Ham Radio Discussions' started by K9KQX, Oct 15, 2020.

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  1. K9KQX

    K9KQX Premium Subscriber QRZ Page

    There's a article on the main qrz page about a renaissance of sorts with militaries seeing a strong case for HF communications. That got me wondering about how back in WWII our militaries could reliably communicate via HF considering all the variables at play with band conditions and propagation. In my 5 years in Ham radio, I've learned the time of the day affects how different bands propagate. Knowing that, even I find it can be difficult to make contacts to far away locations using a band that has the highest probability of working.

    So does anyone know how they managed to keep in touch with remote locations from HQ. Did they relay things alot? Did they have the ability to work stations remotely? Or did they just use brute force with massive beam antennas that many of us only dream of.

    I really find WWII era communications techniques to be fascinating with all the advances they made during that time. It really was amazing what my grandparents generation accomplished.
    WB5YUZ, KE5OFJ, KI5WW and 1 other person like this.
  2. KP4SX

    KP4SX Premium Subscriber QRZ Page

    Much of WW2 (the big one) was during the decline of that cycle. But as everyone knows HF can be pretty brisk until the cycle bottoms out as was the case ~1945. Much of the 'on the ground' activity was starting to move into the low-VHF range.
    To keep it in perspective, it seems to me that there wasn't a huge need for very long-distance comms in the European theatre. Bombers flying out of the UK to Germany (and vice-versa) were just a few hundred miles. Bletchley Park in the UK literally copied every transmission the Germans sent :) Spies with little 5w Parasets could communicate from Norway or the Netherlands back to the UK with relative ease on the lower frequencies and crummy antennas.
    Not sure what freqs U-boats used for their routine communications back to base. That would seem to be a worst case scenario.
    K0UO likes this.
  3. KA6IBM

    KA6IBM Ham Member QRZ Page

    In the movie "Where Eagles Dare' this is HF comms. Calling from Austria to England, I think

    Last edited: Oct 15, 2020
  4. W4IOA

    W4IOA Ham Member QRZ Page

    They did have issues with being rock bound and other units not having the same crystals. In the movie "A Bridge Too Far" it was one of the many reasons the operation failed.
    WB5YUZ and K3XR like this.
  5. VK6ZGO

    VK6ZGO Ham Member QRZ Page

    Many hams used ex military gear following WW2, as did many civil administrations.
    Quite a few Brit & Oz wartime radios had VFOs, so would be reasonably frequency agile.

    When I started working for the old Postmaster General's Dept back in 1965, we were still using ex WW2 Oz designed "AT14" transmitters for CW backup to the landline into some remote inland settlements.
    We had Rhombics at our end, for both receive & transmit, but I don't think the antennas at the other end were near as sophisticated.
    I'm not really sure, but I believe at their end, they used the AWA "3BZ" transmitter- receiver pair, like the WW2 "Coastwatchers" did.

    The Postmasters at the far end all had learnt Morse Code as part of their training, so performed the operator role .
    KA4DPO and KA0USE like this.
  6. G8ADD

    G8ADD Ham Member QRZ Page

    That is misleading. From a bomber airfield in Lincolnshire the German coast was 200 miles, but the southeast corner of Germany or the industrial cities of Italy were more than 700 miles away. For a heavily laden bomber this was close to the limit, particularly as it was suicidal to fly a direct course to your target, so the bomber streams doglegged to confuse the defences.

    The British bombers used an R1155 receiver and a T1154 transmitter. The most common version of the transmitter covered 2.35 - 16.7 "Mc/s" in three ranges, each range having a separate tuner. The antenna was a long wire trailing behind the aircraft, which had to be wound in before landing. There's a lot of information about them on the web, but from the ham point of view they were extensively used in the 1950s by UK hams and found to be prone to drifting, the operators in the bombers, muffled up in heavy flying suits, using them in a cramped "office" right up against the heater vent, had to be skillfull.
    WQ4G, KG4RRH, KA4DPO and 2 others like this.
  7. WA9UAA

    WA9UAA Ham Member QRZ Page

    Washington tried to warn Hawaii of the breakdown in negotiations with the Japanese Empire and the radio circuits were all down, ie. the band(s) were closed. They sent the message by commercial wire and it took days.
    K9MOV, WW0W and NL7W like this.
  8. W4NNF

    W4NNF XML Subscriber QRZ Page

    Communications wasn't always reliable--but it usually was. At any rate, there was no alternative. One thing that helped? Much of the long-distance traffic was on CW, which could usually get through then just as it can usually get through now. ;)
    WB5YUZ, N2EY, WA1GXC and 5 others like this.
  9. KI4ZUQ

    KI4ZUQ Ham Member QRZ Page

    Do not forget the ever-present BC-221 Frequency Standard for zero-beating xmtr and rcvr on the assigned freq. There were variants of this basic oscillator like the Navy LM-16, I think...

    I recall on board ship in the 60's Radio Central was always real busy at night since the "conditions" were better..
    Last edited: Oct 15, 2020
    K4AGO likes this.
  10. N3HGB

    N3HGB Ham Member QRZ Page

    Admiral Donitz famously wanted his U-Boats reporting in frequently and loved to move them all over the Atlantic to go after convoys. The USA and UK had DF stations that did a decent job getting fixes on the subs and it cost many a U-Boat crew their lives.
    My impression in general from a ton of WW II reading is that there was little issue with reliable comms from something like a bomber or a ship. The difficulties were with the HTs of the day, man-portable radios with tubes were not always working right and there were frequency coordination issues aplenty, especially with air-to-ground. I think General Patton requisitioned a pilot and his airplane radio both to ride around with the tanks for this reason.
    Germany, at least at first, sent bombers that could not talk to their own fighters to raid England, but IIRC the fighters could talk to the British fighters :rolleyes:
    KG7LEA, WB5YUZ, US7IGN and 2 others like this.

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