Broadcast - 10 December 2023
Today we will continue on the theme introduced in last week’s broadcast by Justin VK7TW, with his latest auction acquisition, the “Gibson Girl”.
This week it is Idris VK7ZIRs turn with an unusual item. Idris also had luck at the same auction, this time in the form of an 80 Metre AM Transceiver. Also from the same seller and also in immaculate condition internally. I will hand it over to Idris VK7ZIR for an interesting run down on his latest acquisition, the Forestphone:
“I recently attended the NTARC auction and was able to acquire an AWA FP-1 Forest Phone, modified for amateur use. I already have an example of this radio in original condition, but was happy to have one for spares. Throughout most of the 20th century AWA was Australia's leading electronics company, providing a wide range of radio, television, and audio equipment as well and as broadcasting services. Over that time period the company partnered with other companies including RCA, Thorn and Rediffusion. But as an Australian company, the Forestphone FP-1 no doubt was its own creation, a small, easy-to-use, portable transceiver designed for use by forestry crews and similar commercial endeavours back when HF radio was the primary means of communication beyond line-of-sight. The FP-1 I recently acquired was originally built for the Forestry Commission in the state of Victoria. Later users of this radio were gliding clubs, before gliders and balloonists were compelled to move to the VHF air band in the 1980s. They were also used by mobile bee-keepers, inland waterways craft such as houseboats and dredgers, and local government operators in the inland.
The FP-1 is all solid-state, a big plus for battery operation in the field, and being a mid-1960s design uses germanium transistors, including a pair of 2N301As as the modulator. The PA uses two 2N3879 transistors in a push-pull neutralized output stage which uses a toroidal inductor having 11 taps and a second inductor for antenna tuning/matching. Two output connectors are provided with a switch to select between taps that have been set for mobile (presumably close to a 50 ohm load) and as a loading coil for a portable whip. Unlike some similar sets, the FP-1 uses an external battery, which was a plus given how often internal battery leakage caused damage to portable radios. The frequency range is 2-5 Mhz
The receiver is a single-conversion superhet that requires a crystal 455Khz above the desired operating frequency and is very sensitive (Under 2µV). With a little effort, the radio can be used on 80m AM. Full transmit output can be had at 12 to 15 Watts with a 13.8 volt supply. Current drain on transmit is around 3.8 Amps, but on receive draws only 20 mA yet producing high audio output. Small AM (and later SSB) field radios like the Forestphone were the mainstay of the Forests Commission in Australia until the mid-70 when VHF took over. But HF still plays a role in remote regions of the world, and when used with a decent antenna, radios like this are still capable of communication over several hundred miles.
In this modern era when satellite communications are available, virtually anywhere on earth, it is still fun to remember when HF radio was really the lifeline for anyone more than line-of-sight away from civilization and to recognize the trials and tribulations of that form of communication.
I am constantly fascinated by these gems from an era when most of Australia’s communications infrastructure was locally manufactured.”
Thank you Idris, it is certainly an intriguing piece of purpose built Australian made equipment. It is interesting to note that both the Gibson Girl and the Forestphone are rather unusual in their own way and both items originated from the same seller Nic VK7WW.
One other unusual item Nic had in the auction was an incredibly heavy and very large WWII submarine transceiver which really did take three of us to move into position. Evidently the submarine carried three of them! Obviously they had two purposes, one as a transceiver and the other they doubled as the submarines ballast! I wonder who ended up bidding for that one?
Seriously though if you get a chance have a look at the ATV broadcast from REAST on Wednesday the 29th November available on their YouTube channel. Justin gave an excellent rundown on the electronics and mechanical marvels of the Gibson Girl plus some intriguing maritime information on a specially scaled clock for listening watches.
Round up on the end of year club dinner - Twenty five members rocked up to the Iron Horse Bar and Grill on Wednesday evening for the annual NTARC Christmas Dinner.
There was much laughter after we were given directions to the function room, locally known as the VIP room. The only VIP we know is Brendan …… VK7VIP, the one person who couldn’t be there due to Darts match commitments. Sorry Brendan but you missed out on your very own VIP room. We all made up for it though. Much discussion of the menus extensive variety of culinary delights and luckily everyone found something suitable. Orders were taken and service was fast. The food was magnificent, everyone was happy and the staff were fantastic. A great time was had by all. We all made our way home thoroughly satiated.
Club membership renewal - It’s that time of the year again - All club members should have received an e-mail with instructions on renewing their membership for 2024 by now. For those that have not received a renewal please e-mail the secretary@ntarc.net This will allow us to update your e-mail address as there has been a large number of changes this year due to some internet providers divesting themselves of the bother of hosting e-mail also.
UPCOMING EVENTS
Club General Meeting – The last one for the year is this Wednesday 13th December. Held at the NTARC Club Room, Rocherlea Scout Hall, Archer Street, Rocherlea. Meeting commences at 7:30pm. Light refreshment to follow.
The TestNet and TechNet session – The last net will be held on Wednesday night the 13th of December. TestNet/CW course on 3.580MHz from 7pm till 7.30pm…. and a TechNet on 3.567MHz from 7.30pm till about 8.30pm. Your host for the evening will be Nic VK7WW. Although this is the last official net for the year listen about on a Wednesday night, you might be surprised how many need a fix.
The last Coffee Morning for this year will be – this Friday the 15th December in the NTARC Club rooms. Time is from 10am to noon and we look forward to seeing you all there. So why not pop in for the last time this year and join us for a cuppa and chat.
Club Technical night session - Technical nights are in recess and will be resuming on Wednesday the 17th of January, commencing at 6.30 pm at the Club room Archer Street, Rocherlea.
FINALLY - A reminder to all members that if you have any items of news you would like added to our weekly roundup, no matter how trivial, then please email them to the Secretary at the following address news@ntarc.net all items to be received no later than 5pm on the Friday prior to the Broadcast.
Just before I go, I must admit that this week during the north south SSTV session I was lucky enough to see the latest Antenna Tuna from John West…. Go on check it out, you know you want to.
That’s all folks,
73 from Stefan, VK7ZSB, Secretary NTARC Inc.
