Arteom Posted October 20, 2012 Share Posted October 20, 2012 (edited) Quick question guys, I want to order a 10db 50 ohm attenuator to make sure I get just enough signal for my display, and so I don't get in trouble with the guys in the black van...I have a 500mW Transmitter and want to bring the power down to 100mW, according to someone, saying somewhere 100mW is legal.. not sure how true that is...Anyways for me 500mW is too powerful? Where can I get an Attenuator for the right price to do the job for me? Edited October 20, 2012 by Arteom Link to comment Share on other sites More sharing options...
JeffF Posted October 20, 2012 Share Posted October 20, 2012 I have used the ones on this page for the past few years...http://www.mpja.com/Scope-Probes--Test-Leads/products/57/Quick question guys, I want to order a 10db 50 ohm attenuator to make sure I get just enough signal for my display, and so I don't get in trouble with the guys in the black van...I have a 500mW Transmitter and want to bring the power down to 100mW, according to someone, saying somewhere 100mW is legal.. not sure how true that is...Anyways for me 500mW is too powerful? Where can I get an Attenuator for the right price to do the job for me? Link to comment Share on other sites More sharing options...
Arteom Posted October 21, 2012 Author Share Posted October 21, 2012 I have used the ones on this page for the past few years...http://www.mpja.com/...ds/products/57/The 10bd says it's power is 1W if thats output power thats more than needed, it should be .1W or 1/10 of a watt? Link to comment Share on other sites More sharing options...
Arteom Posted October 21, 2012 Author Share Posted October 21, 2012 (edited) ... Edited October 21, 2012 by Arteom Link to comment Share on other sites More sharing options...
Orville Posted October 21, 2012 Share Posted October 21, 2012 I have used the ones on this page for the past few years...http://www.mpja.com/...ds/products/57/Me too. No issues at all with it. Direct link to the one I use: http://www.mpja.com/10db-Feed-Through-Attennuator-Terminator/productinfo/16547+TE/@ Arteom: I believe that 1 watt is it's maximum power rating, not what it outputs, if it was doing that I think by now I'd have already had a little visit with the guys in black suits, dark glasses and black vans.It cut my MBB Eclipe 4000 power output down from transmitting 2-5 miles to around 500' or a bit over, yes still a bit over the 200' limit.Been using this particular unit for 3 years now, works for my needs and thus far no FCC visitations. Link to comment Share on other sites More sharing options...
Arteom Posted October 21, 2012 Author Share Posted October 21, 2012 (edited) I Want to cut my range to 200'... i'm good, the current chinese unit transits around 500' now anyways, and its a 500mW I'm just scared of this whole FCC thing... Why risk it!?! Are you sure the direct link is to the one that will work for me to cut the power DOWN? Did anyone try to call that company to see if they can get cheaper shipping? I mean $10 for that little thing is ridiculous! Flate rate shipping is $5 Edited October 21, 2012 by Arteom Link to comment Share on other sites More sharing options...
Arteom Posted October 21, 2012 Author Share Posted October 21, 2012 (edited) Repost again.. oops, no way to cancel... sorry Will this work...http://www.ebay.com/...=item1e7246ee81 Edited October 21, 2012 by Arteom Link to comment Share on other sites More sharing options...
JeffF Posted October 21, 2012 Share Posted October 21, 2012 (edited) The 10bd says it's power is 1W if thats output power thats more than needed, it should be .1W or 1/10 of a watt?It's an attenuator...http://en.wikipedia....r_(electronics)And here's how attenuation works in regards to power output...http://sss-mag.com/db.html Edited October 21, 2012 by Jeffrey Link to comment Share on other sites More sharing options...
GaryM Posted October 21, 2012 Share Posted October 21, 2012 The 10bd says it's power is 1W if thats output power thats more than needed, it should be .1W or 1/10 of a watt?That is its maximum input power rating. Its a passive device, does not generate power.A 10 dB attenuator on a 500 mW output will give you 50 mW output (10 log of the power ratio).As has been discussed here ad nauseum, part 15 does not dictate a power output limitation, but a field strength limit. While you can estimate and say "x mw will keep me within limits", it is truly an estimate. Link to comment Share on other sites More sharing options...
Arteom Posted October 22, 2012 Author Share Posted October 22, 2012 Wow, thanks guys... those links helped me out a-lot Jeffrey, I'll go ahead and see if I can get cheaper shipping on the 10 DB model.. Link to comment Share on other sites More sharing options...
Arteom Posted October 22, 2012 Author Share Posted October 22, 2012 I recently contacted an eBayer...The attenuation will be relative to the input. For instance, 3 db is commonly referred to as "half-power". 3 db cuts any input in half. 6 db will reduce the input to 1/4 of its original power (3 cuts it in half, then 3 cuts that half in half, leaving a quarter of the original).In your case, 6 db will bring you to 125mW. Is that close enough?10 db attenuates by a power of 10. So 50W would be attentuated to 5W. 500mW would be attenuated to 50mW.Attenuation is basically "negative gain". This calculator will provide good numbers expressed as "negative gain", i.e. -10db of gain. This is actually attentuation.http://www.rf-amplifiers.com/index.php?topic=gainEnter your starting power as the input power (500mW) and your desired power as the output power (100mW) and the calculation will be -7db. You can play around to find acceptable power levels.I have one 6db attenuator left, which will bring your output power down to approximately 125mW.http://www.ebay.com/itm/130766270081?ssPageName=STRK:MESELX:IT&_trksid=p3984.m1555.l2649Thanks and I hope that I have been of some help. Link to comment Share on other sites More sharing options...
Guest Don Gillespie Posted October 22, 2012 Share Posted October 22, 2012 I recently contacted an eBayer...The attenuation will be relative to the input. For instance, 3 db is commonly referred to as "half-power". 3 db cuts any input in half. 6 db will reduce the input to 1/4 of its original power (3 cuts it in half, then 3 cuts that half in half, leaving a quarter of the original).In your case, 6 db will bring you to 125mW. Is that close enough?10 db attenuates by a power of 10. So 50W would be attentuated to 5W. 500mW would be attenuated to 50mW.Attenuation is basically "negative gain". This calculator will provide good numbers expressed as "negative gain", i.e. -10db of gain. This is actually attentuation.http://www.rf-amplif....php?topic=gainEnter your starting power as the input power (500mW) and your desired power as the output power (100mW) and the calculation will be -7db. You can play around to find acceptable power levels.I have one 6db attenuator left, which will bring your output power down to approximately 125mW.http://www.ebay.com/...984.m1555.l2649Thanks and I hope that I have been of some help.didn't Gary just mention this a few posts up?? Link to comment Share on other sites More sharing options...
Arteom Posted October 23, 2012 Author Share Posted October 23, 2012 (edited) didn't Gary just mention this a few posts up??Yes, I just decided to share it I have a quick question though, will the 10db unit bee too much of a power decrease? Thats only 50mW when currently my radio only travels around 500'?What's the return policy like on MPJA? Has anyone dealt with that before? Edited October 23, 2012 by Arteom Link to comment Share on other sites More sharing options...
Arteom Posted October 23, 2012 Author Share Posted October 23, 2012 Anyone? Link to comment Share on other sites More sharing options...
shfr26 Posted October 23, 2012 Share Posted October 23, 2012 Check the webpage for return policy. Link to comment Share on other sites More sharing options...
Guest wbottomley Posted October 23, 2012 Share Posted October 23, 2012 Yes. Try this. Link to comment Share on other sites More sharing options...
Arteom Posted October 23, 2012 Author Share Posted October 23, 2012 Yes. Try this.LolI'm still unsure if I should go with the 10 db? Link to comment Share on other sites More sharing options...
rescue_653 Posted October 23, 2012 Share Posted October 23, 2012 I will put it simple if at 500mw you only got 500 ft the crickets are all anyone will here during your display unless standing beside the house because 50mw is not even going to transmit out of the house. Link to comment Share on other sites More sharing options...
Max-Paul Posted October 23, 2012 Share Posted October 23, 2012 Will you get the bloody 6db attenuator and be done with it. This will lower your power to 125mW at the antenna. I cant see you having any problems, unless you put some dang dipole on it. And put it 50' above your roof. Them little antennas that come with the transmitter do a wonderful job for our purpose. Link to comment Share on other sites More sharing options...
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