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250mW vs 600mW

Discussion in 'FPV (First Person View)' started by icordoba, Jun 9, 2014.

  1. icordoba

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    Hi,
    I plan to get a FTP system for my Phantom II.
    http://www.hobbyking.com/hobbyking/stor ... 00mw_.html

    I wonder what are, if any, the drawbacks of installing a 600mW transmitter vs. the lower power ones (200/250mW for example). What is the reason of installing these lower power system? Do they have a better power consumption and so give you some extra minutes of flight... are they less prone to interfere with the command control signal... ? I think the difference in price is very small not to go for 600mW.

    I won't be flying my drone out of my line of sight so I'm really not interested in getting a very long range video, so that's why I'm considering 200/250mW. Thanks for any opinion/advice.

    Ignacio @ Madrid
     
  2. IrishSights

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  3. wkf94025

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    You will be fine with the IRC 250mW. I have both IRC's and have gone just under 4km with the 250mW. I doubt you will notice much difference in flight time. You save a few grams, and few euro, and still get excellent range with the IRC 250mW. Make sure you chose well on antennas. What is your FPV viewing device?

    Kelly
     
  4. icordoba

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    Thanks for both replies. It seems that for my needs I don't need 600/1W power but just good tx and rx antennas. I'll probably be installing:
    http://www.hobbyking.com/hobbyking/stor ... aff=773910
    with
    http://www.hobbyking.com/hobbyking/stor ... aff=773910

    About the las question still don't have viewing device, so also need advice on that too is welcome (I've googled and searched her and there are so many threads...). As most beginners I sit between going for FatShart or Boscam:

    Something like http://www.hobbyking.com/hobbyking/stor ... aff=773910 but this one seems to have no internal batteries. Any recommendation on this?

    Again, thanks :)

    Ignacio @ Madrid
     
  5. QYV

    QYV

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    I'm not trying to directly disagree with any previous posters, just offer more info... I like you tried to shoot on the low end of power to reduce drain on the Phantom battery (assuming you plan on tapping into Phantom power like most people) and got that same 200mW transmitter you linked. I get a lot of interference and very short range (under 50m) in high interference area such as urban environment.
    common wisdom around other threads is that the power drain of a ~250mW transmitter vs a 600mW or so is negligible, you're talking maybe a few seconds flight time difference so that being equal, you might want to go with a higher power transmitter like 600mW just so you don't run into any issues with interference like I did... they're not that much more expensive.

    like others said antennas make all the difference.. you should definitely splurge on really good properly tuned antennas, there's a great site called FPVLR.com or I'm sure you can find something more local.

    goggles vs a display is both price and preference. You can get that Boscam RX-LCD5802 for under $200usd, or goggles even the crappy ones are more expensive than that, and the high end goggles are 3-4 times the cost... but goggles supposedly give you a much more immersive flight experience so it depends on what you're looking for. I personally am fine with that little Boscam receiver, I like how it has a built in battery and I don't have to deal with carrying around batteries, just the charger.
     
  6. wkf94025

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    I generally fly in rural, low density environments, so I can't speak to optimal power levels for high-noise urban environments.

    I would offer that I see lots of posts with problems when pilots mix IRC transmitters with Boscam receivers. If you're going IRC in the air, I would go IRC on the ground. Either Fatshark goggles with receiver built in, or their Uno or Duo receivers connected to a flat screen. I use both, like both, and there are times when I prefer one over the other. Goggles give a great immersive experience for very smooth video navigation, provided your radio is set of for de-sensitized inputs, smooth yaw, etc.

    Kelly
     
  7. icordoba

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    I'm definitely going for a Monitor, not Googles at this point.

    I'm narrowing my search; I will probably choose between a Boscam combo or the Fatshark one:

    Boscam:
    500mw transmitter:
    http://www.hobbyking.com/hobbyking/stor ... duct=22394
    And either one of this screens:
    http://www.hobbyking.com/hobbyking/stor ... duct=51470
    http://www.hobbyking.com/hobbyking/stor ... duct=35055
    Still don't decided on DVR or the dual antenna. Probably will go for the latter as I don't see DVR is not a must... any opinions?

    Inmersion:
    http://www.hobbyking.com/hobbyking/stor ... 00mw_.html
    Any recommendation of monitors for this?

    Thanks,
    Ignacio
     
  8. wkf94025

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    I have only used the Lilliput 664/W screen. I have zero experience with any other screen. The Lilliput is not cheap, but image quality is very good. It's built-in receiver is not that great, but great antennas should give you 1,000m or so with the built-in receiver. I use the Duo receiver, with a helical antenna, and either a CP mushroom, or a patch.

    In my opinion, and based only on reading other posts, if you are getting < 500 meters, you have some fundamental antenna or frequency problems. An all-Boscam or all-IRC/Fatshark system should get well beyond 500 meters. Mixing brands likely to result in marginal results, unless you have a PhD in RF.

    Kelly
     
  9. QYV

    QYV

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    again I'm not speaking from direct experience since I don't have DVR system, but I think the only reason to have one is if you expect to lose the Phantom at distance and want to backtrack visually or with the GPS data from an iOSD and try to figure out where it crashed. The footage you're recording directly on the GoPro will be magnitudes better than recording the broadcast I'm pretty sure.

    When you say "DVR or dual antenna" do you mean from a cost perspective like you only have money for one or the other? You should definitely be planning on getting upgraded antennas from the stock ones that will come with the video Tx and Rx. If you watch the first few minutes of this video you'll get a better understanding of why antennas are so important, and why the stock ones you'll get are crap. it really helped me and a lot of other people around here. So if it's a cost thing, get good antennas first and save up for the dvr later. imho

    So you'll want good antennas: 1 for the Tx on the phantom, 2 on the Rx assuming you get a diversity receiver. diversity receiver just means it has 2 antenna inputs, and will show the signal from whichever antenna has better signal at any given moment. Most people will put both a helix (which can receive from further range but is directional - needs to be pointed at the Phantom) and a pinwheel antenna (which is shorter range but more omnidirectional) on the receiver... whether it's a display or goggles. that way you've got long and short distance optimal reception.

    for example a lot of people get a bundle like this
     
  10. wkf94025

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    Spent $115 on the Lumenier DVR. Like it a lot. Yes, analog video quality is much worse than GoPro. However, yes, quite useful for lost model recovery, and also for stepping frame by frame through OSD when doing post-mortems on VRS and other flight issues.

    Kelly
     
  11. icordoba

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    Hi,
    thanks for all replies.
    I agree with all your points QYV. My doubt on wether DVR or dual antenna was because of Boscam offering, either the single antenna with DVR or the RX LCD 5802, which is the one I finally chose. I also like it as has builtin rechargeable battery. (I though of the utility of DVR for crash recovery but opted for the other option anyway)
    I wanted Boscam as I went for the 400mw Boscam transmitter, TS353. I also got this antenna in the package for the transmitter:
    http://www.banggood.com/5_8G-3-Leaves-O ... 73560.html

    Now I just need to choose antennas for the receiver... will probably wait for the order to get here (ordered everything to bang good.com).

    I'll post a review once I have everything working, but I don't think that will be earlier than 15 days. Until then thanks for any advice on installing the setup. (Will include DJI iOSD, of course)

    Thanks,
    Ignacio
     
  12. QYV

    QYV

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    I gotta tell you man, that's the same antenna I got for mine first and it's utter crap. I feel like that was a $7 lesson learned, real decent antennas just don't come that cheap. I mean maybe you'll somehow have better luck than me but fwiw I got better range with the stock antenna that came with my TS351 than that one, and both were around 20m in urban area and 100m otherwise.

    There's a reason that antenna is $7 and good ones are $40-60. :)

    I followed this guide when installing my iOSD and FPV kit. It's for a H3-2D so if you've got a -3D that bit will be slightly different but the iOSD part and FPV cabling would be the same and there's tons of H3-3D mounting videos out there. FYI if you're wondering you do NOT want the "DJI FPV hub" as it's only for connecting the DVI AVL58 transmitter, so just do the power and video soldering yourself, it'll be the same for a H3-3D.

    don't forget to pay attention to where the channel dip switches are on the video Tx... on a TS351 you can't reach them after you mount. I just used outdoor, double sided sticky tape to mount the vTx to the bottom of the Phantom, I double layered it and have never even remotely felt like it was close to coming loose.
     
  13. Submariner

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    I also have the Boscam monitor with TS352 (600mw) Tx.

    Just curious, does channel selection factor in at all in performance, signal strength etc? I just kind of chose a channel at random on my Tx and scanned my Boscam to pick it up. :|

    http://image.helipal.com/helipal-boscam ... manual.pdf
     
  14. QYV

    QYV

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    supposedly there is slightly different wattage on the different channels. I really don't know the source of the information so take it with a grain of salt but this thread discussed it a bit... the TS352 isn't specifically mentioned but as you can see the other Boscam transmitters are stronger on the first channels than the latter channels, so I stick to channels 1-4. the guy that made my antennas said they work best on channel 1 so I'm sticking with that
     
  15. Rufus

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    I have the same setup and with my new antennas I am very pleased. CH1 frequency 5705 Mhz.
    Wrote this a while ago under this Subject: Boscam is not the best, june 05.

    I have a Boscam ts 352 and Boscam RX-lcd 5802 and have changed my antennas to these from fpvlr.com

    download/file.php?id=6005

    I got them yesterday and today I went out for a 2000 meter trip with perfect picture even when I turned around and went home. I´m very impressed with my Boscam equipment and for me 2000 meters is the limit to have enough power to get my Phantom home in a safe way. I had 60 % of batteripower when I landed and that feels fine for me.
    I strongly recommend to change the antennas because that was what made the difference for me. All that interference in the monitor disappeared and I have the monitor mounted on top of the transmitter
     
  16. Submariner

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    Nice antennas Rufus. Do you have link as to where you obtained them? I'm thinking of getting a helical like you have.
     
  17. Rufus

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  18. GhostMaster

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    yes it does, check this table that has the output power for the most used video tx:

    [​IMG]

    My personal setup for FPV that is proved to be very good is this (max range tested was 2km):

    Video Tx:
    Boscam TS353 400mw: http://j.mp/1gJ6t7s

    LCD with Receiver and battery:
    Boscam 7" RX-LCD5802 5.8GHz Diversity Receiver: http://j.mp/1lZuham
    LCD Battery Charger: http://j.mp/1h3CreQ
     
  19. icordoba

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    Very glad to read that. That's the setup I chose (also got it at Banggood.com 9th June but I still haven't received it). Sometimes waiting is so hard...