erice 732 Posted May 22, 2015 Share Posted May 22, 2015 hi all, bought a cheap ssb off tm connected to 12volt battery charger and ..................... nothing power is getting through the fuse and being switched by the on-volume switch but nothing lights up, no hiss from speaker, no clicks from mic google turned up very, very little about them probably from about 1975, made by AWA NZ, only 25W? output power and were fitted to coastal fishing boats that didn't need ocean spanning power has built in antenna tuner tomorrow will try hooking it up to the car battery as i know from working on the autotiller that the battery charger doesn't provide a very smooth 12VDC but it may even need 24VDC? anyone ever seen 1 before? is there an ssb Xstal radio guru about? Quote Link to post Share on other sites
wheels 543 Posted May 22, 2015 Share Posted May 22, 2015 Several things with these old units. Firstly, they are fitted with Valves, whuch suck precious juice from the Batts. Secondly, because they are valves, they take a minute or so to warm up. Thirdly, because there are valves, one may well be dead.If you want to step up a grade, I have a Codan unit with separate Tuner we could d a cheap deal on.By the way, NEVER EVER press transmit on these things if you do not have an antennae connected. Quote Link to post Share on other sites
Clipper 343 Posted May 22, 2015 Share Posted May 22, 2015 Why not wheels (press transmit with no antenne) ? Quote Link to post Share on other sites
erice 732 Posted May 22, 2015 Author Share Posted May 22, 2015 not so old it has valves what sort of codan? Quote Link to post Share on other sites
erice 732 Posted May 22, 2015 Author Share Posted May 22, 2015 Why not wheels (press transmit with no antenne) ? if i remember my radio theory correctly something about a big fat wad of RF energy having nowhere to dissipate, so it can burn up? in the tuner Never use the system without reliable ground connection. Never transmit or tune without an antenna. It will damage your tuner High voltage! Do not touch the antenna when it’s transmitting or tuning http://www.onz.be/antennes/cg3000N.pdf Quote Link to post Share on other sites
erice 732 Posted May 23, 2015 Author Share Posted May 23, 2015 ughmm ug hmm embarrassed cough while connecting 12vdc today. realised that the 2 wires going in to + and earth of the terminal block were not the wires needed to power it up but + and - so moved the earth wire to the - terminal and now the power switch makes leds glow, mic switch clicks a relay etc so progress but more to do much more Quote Link to post Share on other sites
erice 732 Posted January 1, 2016 Author Share Posted January 1, 2016 hmmm............ not having much luck with this old awa ssb wheels, still willing to trade that old codan? interested in a couple of sturdy norwegian comrod antennas? 5mtr HF whip (2 piece) and a vhf http://www.serviceport.se/en/products/antennas/marine-civil/mfhf/comrod-ar55m.html http://www.boatelectronics.co.nz/index.php?route=product/product&product_id=55 Quote Link to post Share on other sites
wheels 543 Posted January 1, 2016 Share Posted January 1, 2016 Why not wheels (press transmit with no antenne) ? Sorry I didn't see that question. The output devices need a load to work into. Tuning the antennae to the correct length increases the load. If you have to little load presented to the output devices, you can destroy them. Valves in older sets can also be damaged, but for a different reason. In fact any valve amplifier of any form can be damaged if you operate it with no load, including Audio amp with no speakers. The Valves work in such a way that they think Oh I am not working hard enough, I will increase my output, oh still not working hard enough, must work harder till it has a heart attack. Audio Amps of transistor design don't work that way and are safe. But the lectric critters of RF frequencies are a different bread of animals and can go places they shouldn't and try mating with devices they shouldn't and as they say in the electronics world, the secret factory installed blue smoke gets out and no one has designed a way of getting the blue smoke back in again. erice, I forgot. It is sitting under my work desk at home. Of which of I had of thought about it, I could have brought it up with me and saved you freight. Won't be back home till late Jan, so if you don't hear from me early Feb, send me a PM. It is either this model or very similar, although I am pretty sure it has a separate Antennae tuner, so could be wrong on model, but the looks are pretty much the same from what I can remember. http://www.hfradiosales.com.au/codan_%20barrett_hf_radio_information/RADIOS/8121.htm A page that may well be helpful one day, http://www.mods.dk/manual.php?brand=codan When if comes to HF radio, SSB is AM, not FM like a Marine VHF. So the negative of the Antennae system needs to be connected tothe Water. The water is the Earth. The actual radio frequency itself sets its oscillation up between the Earth and the ionosphere. This is the reason why you can communicate with someone a long way away and often, can't communicate with someone much closer. The base of Ionosphere changes it's altitude at night to what it was during the day, and also it's reflective ability and base altitude during Solar activity striking the Earth. So hence why HF can sometimes work great and sometimes be lousy. FM is not subject to that kind of thing. So a good Earth is essential and should not be considered as 'just an earth", but actually the Ground Plane of your antennae system. When it comes to the electrical energy in the antennae during transmit, as anyone would know if they held the thing when someone talked, you get one hell of a good bite from it. The actual voltage being transmitted is not really that high. It is the fact that the power is more " dense". If you draw a Sine wave and shade the inside of the wave in, all that shaded area is what effectively is "Power". All the area not taken up is nothing. But now if you draw the wave really tightly together so as much of the empty space is now taken up as shaded as well, then you can now see that the area that contains the "power" is much more concentrated. So as a result, the voltage does not have to actually be increased to still see a major increase in power available. It is also a major reason why transmitters are exponential in cost as Power doubles. It takes some serious devices to transmit the energy. And looking another way at it, it is also why the extreme frequency spectrum's, like Cllph etc, can use such little power yet transmit so far. The actual energy transmission is intense in regards to the very very small voltages used. Of course it is far more complex than that with digital involved with Cllph, but you should get the gist of it. Quote Link to post Share on other sites
erice 732 Posted January 2, 2016 Author Share Posted January 2, 2016 hi wheels i'll take you up on that codan when you get back from your travels the 6801? seems pretty common here and uses a separate ant. tuner but otherwise seems to share the internals with the marine designed 8121............either would be good for my mucking around, listening in (no broadcast without licence) if either or both of those antennas are any use to you, (or good for your stock of spares on board?), i'll be driving up to whangaroa tomorrow with the kids and then to mangonui on the 6th before heading back to akl. Quote Link to post Share on other sites
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