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no more Sombra Labs Receivers

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Re: no more Sombra Labs Receivers

Postby Giovanni » Sat Aug 17, 2013 8:14 pm

Yes.
Kind regards,
Giovanni

Alexander Engel 1/48th scale Gato
Graupner MC-19 radio converted to 75MHZ

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Re: no more Sombra Labs Receivers

Postby jonel » Sat Aug 17, 2013 9:01 pm

The Jeti DC-16 radio certainly looks good although the current cost is high.. I read the manual and wonder if anyone familiar with the radio can tell me something. Assuming you do connect an rf module to the transmitter as proposed for 75 mhz output, does the original 2.4 gig output stop or continue?

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Re: no more Sombra Labs Receivers

Postby Sub culture » Sun Aug 18, 2013 6:00 am

You really need to speak to Jeti or a distributer for that kind of information. You can disable RF transmission in software mode, whether this also cripples the PPM out, I don't know.
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Re: no more Sombra Labs Receivers

Postby bwi » Sun Aug 18, 2013 11:21 am

Gents,

Reading this thread, made me worry. I'm new to the subs business, just started on an akula build, and I have no electronics yet. So I informed myself about the situ in Europe, seems like the same problem over here :cry: . The only way to get a 40mHz system (Europe) is to by it secondhand. I'm now in a hurry to purchase one.

Grtz,
Bart
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]"Samuel Smiles"
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Re: no more Sombra Labs Receivers

Postby JWLaRue » Sun Aug 18, 2013 12:30 pm

Bart,

The good news (for us) is that there are a lot of the older radios being sold for very low prices. There are enough out there that we'll be good for quite a while yet.

-Jeff
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Re: no more Sombra Labs Receivers

Postby Giovanni » Sun Aug 18, 2013 1:05 pm

Sub culture wrote:You really need to speak to Jeti or a distributer for that kind of information. You can disable RF transmission in software mode, whether this also cripples the PPM out, I don't know.


I just sent an email to Jeti. They are usually slow to reply but will post their answer ASAP.
I would guess that since the PPM output doubles as a hard wired trainer plug that the 2.4GHz transmitter would not be disabled. I would only be needing the telemetry receivers to operate when the 75MHz transmitter is working.
Last edited by Giovanni on Sun Aug 18, 2013 1:09 pm, edited 1 time in total.
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Giovanni

Alexander Engel 1/48th scale Gato
Graupner MC-19 radio converted to 75MHZ

"Anything one man can imagine, other men can make real." — Jules Verne
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Re: no more Sombra Labs Receivers

Postby Giovanni » Sun Aug 18, 2013 1:07 pm

bwi wrote:Gents,

Reading this thread, made me worry. I'm new to the subs business, just started on an akula build, and I have no electronics yet. So I informed myself about the situ in Europe, seems like the same problem over here :cry: . The only way to get a 40mHz system (Europe) is to by it secondhand. I'm now in a hurry to purchase one.

Grtz,
Bart


Their are many "like new" Graupner MC-19 40MHz radios in your neck of the woods and they are usually well taken care of and reasonably priced. I bought mine in Germany for $300.00 and that was nearly 2 years ago. My radio also has all of the optional marine switches that were with the radio.
Kind regards,
Giovanni

Alexander Engel 1/48th scale Gato
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"Anything one man can imagine, other men can make real." — Jules Verne
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Re: no more Sombra Labs Receivers

Postby jonel » Sun Aug 18, 2013 1:35 pm

I went to a hamfest yesterday and saw some 50mhz sets for sale. Being a ham, this is my choice as 50 mhz penetrates water better than 75 mhz.

For anyone interested in pursuing alternative methods of sub control, there is a goverment study here http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3355409/ most of it is boring but if you take the time to wade through it to the comparison charts it might save someone the time and expense of experimenting with dead ends.


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Re: no more Sombra Labs Receivers

Postby Giovanni » Sun Aug 18, 2013 3:31 pm

From what I have read in numerous test articles is that there is not a lot of differences in signal strength under water. It may be a good choice for you. You may want to buy some of Sombra Labs leftover Ham frequency receivers.
Kind regards,
Giovanni

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Re: no more Sombra Labs Receivers

Postby salmon » Sun Aug 18, 2013 4:00 pm

bwi wrote:Gents,

Reading this thread, made me worry. I'm new to the subs business, just started on an akula build, and I have no electronics yet. So I informed myself about the situ in Europe, seems like the same problem over here :cry: . The only way to get a 40mHz system (Europe) is to by it secondhand. I'm now in a hurry to purchase one.

Grtz,
Bart


Yes, reading this thread can cause a lot of angst about the future of our frequencies and we should be concerned.....BUT there are still new transmitters out there (Futaba was already mentioned). wFly is another. The message was lost because of the delivery, here is one such radio http://www.sub-driver.com/electronics/radios-transmitters-and-receivers/wfly-6-channel-transmitter-40mhz.html new, not used, not needing to be modified in 40mhz. I am not trying promote a vendor (no more than others mentioning hobbyking.com or espiritmodels.com or even ebay.com), I did a search and did not find anyone else carrying it.
It will be a self fulfilling prophecy if we do not support those manufacturers that do have our frequency, why should they then continue making them? At this moment in time, there are new units available.
If you can cut, drill, saw, hit things and swear a lot, you're well on the way to building a working model sub.
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Re: no more Sombra Labs Receivers

Postby bwi » Sun Aug 18, 2013 5:13 pm

Thks, couldn't agree more.
Grtz,
B
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Re: no more Sombra Labs Receivers

Postby KevinMc » Sun Aug 18, 2013 7:34 pm

JWLaRue wrote:That definitely helps. So two of those wires is where one would need to splice in the two wires that would go to the antenna.

Hi Jeff,

Not quite - the signal that comes off this line is what gets fet into the transmitter module, and from the module it is sent to the antenna. You can basically break down an RC transmitter into a box of pots and switches which are all read by an encoder block, the encoder feeds a transmitter module, and the transmitter module drives the antenna. The PPM signal in question is almost certainly the output of the encoder to the transmitter module. This is the same signal that's used in a trainer-mode setup with RC aircraft, or fed to a computer to operate a simulator.

Typically when the encoded signal is routed from to the trainer port the transmitter module is disabled. (At least that's how it works with aircraft transmitters.)
Kevin McLeod - Oscar II driver
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Re: no more Sombra Labs Receivers

Postby JWLaRue » Sun Aug 18, 2013 9:05 pm

Kevin,

Thanks for the correction. So the "antenna" lead from the motherboard connector should not be connected to anything, yes?

-Jeff
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Re: no more Sombra Labs Receivers

Postby Giovanni » Mon Aug 19, 2013 12:46 am

You want to connect the antenna to the 75MHz transmitter module.
I'm assuming that the Jeti 2.4GHz telemetry will operate as long as you use Jeti sensors.
The Jeti sensors are transmitting data directly to the Jeti radio receiver.
Kind regards,
Giovanni

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Re: no more Sombra Labs Receivers

Postby Sub culture » Mon Aug 19, 2013 5:23 pm

As has been pointed out, it's newcomers to the hobby which are having a hard time finding equipment. Long gone are the days when you could jog along to the local model shop and pick up a new 40mhz set. One or two places still keep a small quantity of sets, but the choice is very restricted.

Engel are still stocking 40mhz equipment, for the time being, and you might luck out and hook a new set in model store if they have something gathering dust in the back cupboard. European radio manufacturers? Jeti are it really. The other makes are just offshoots of far east brands e.g. Multiplex/Hitec, Graupner/JR, Robbe/Futaba. We used to have a good manufacturer of radio here in the UK called Fleet. Very nice sets, I still have and use Fleet equipment, nice old school aluminium cases with fully gimballed sticks etc. no SMD components either, which makes it a bit easier to work on if required. But in the end Fleet packed in, as the margins got too small for home grown kit to compete with imported sets.

Perhaps eventually we'll be back to supply kit based tuning models to plug into newer sets, a potential cottage industry for someone who knows their way around a tuned circuit.
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