Franklin R850 External antenna

Finn Lassen

If you live in a rural area with trees blocking line of sight to nearest Sprint tower and can't get a reliable connection, there is a solution.

My initial test was to put the Franklin in a bag taped to a long pole and raise the pole up to about 35 feet.Going from unreliable 1 bar to 2 bars, I knew that an external antenna would work.

The Franklin does have an external antenna connector.

Remove the back cover. Carefully remove the thin adhesive cover opposite the battery connector and opposite the reset button. (When looking at the display it will be on the lower left) The one labeled "Main" in the pictures in this thread:

https://www.howardforums.com/showthread.php/1889475-Franklin-R850-amp-External-Antenna/page4

I'm still not sure what connector type it actually is (TS9, MS-160, MS-162, ...) I used a RG316 MS162 Male Angle to FME MALE Coax RF Cable to connect to a 14 element Yagi antenna that I already had. I had to carefully remove the rim on in MS-162 angle connector with a Dremel tool.

On the debug screen I saw it was connecting on Band 26. Looking that up it's on 800MHz, so my 9 year old Yagi should work.

Mounted on a 50 foot pole (height is everything!), I went from unreliable intermittent 1 bar to reliable 2 bars and sometimes 3 bars. I would probably be getting better results with a brand new antenna and cable.

 

Finn

Comments

8 comments

  • Comment author
    Mitch S

    I think I was under the assumption that the antenna connector on the R850 was just for broadcasting WiFi signal, similar to the dock for the 77XS seen here.

    But this is good info for the enterprising DIY-er who's on our hotspot promo.Thanks, FInn!

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  • Comment author
    Finn Lassen

    There are actually 5 connectors:

    WiFi

    Main (cell tower antenna)

    Div (Diversity, second cell tower antenna when using two different bands with significantly different frequencies)

    Chan 41 (no clue)

    Chan 41 (no clue)

     

    So, yes, you could also attach an external WiFi antenna if you have difficulty connecting to the Franklin from some area in your house.

     

    Finn

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  • Comment author
    George Murphy

    one day PCs will be the size of a hotspot puck. nice info though even with 1 bar LTE i get 25Mbps which is fast enough for large file transfers. we should be given the msl login so we can tweak the frequencies and power settings in http://myhotspot/hidden. would be nice if the hotspot had open tethering and linux coreutils for terminal commands like shutdown for instance.

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  • Comment author
    Mitch S

    If you're not already given the MSL on the Device Settings tab of your dashboard (it should be there) we can usually provide it at help@ting.com if you just ask. In most cases, we can pull it up. In the rare instance, Sprint doesn't have the MSL in their database and thus we're unable to provide it. But that's relatively rare.

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  • Comment author
    George Murphy
    • Edited

    oh cool i never connected those dots. thanks alot. looks like ssh is supported so it can be tethered and commanded sweet. brave new world ;]

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  • Comment author
    George Murphy

    OP you should try band 41 now that you have an outdoor antenna. I think the diversity connector can assist attenuation on the receiving band. no harm in connecting 2 antennas.

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  • Comment author
    Finn Lassen

    Not sure my Yagi (or the old 32 foot cable to it) can handle those frequencies. I know they are multiples of the 700-900MHz that my Yagi is tuned for, but suspect the loss in the cable may attenuate the signals too much. More antennas: more cable, more pigtails: more $. What is the advantage of using band 41? How would I know if the tower (Physical Cell ID 134, Cell Global ID 78179355) actually provides channel 41? Why are there two connectors for channel 41 -- does it require two antennas?

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  • Comment author
    George Murphy

    im no expert but band 41 is hardly used. think any sprint tower will support it. it generally uses a wide bandwidth and i guess using 2 or more antennas doubles the reception bandwidth. should be faster and go farther but wont penetrate matter as well as pcs signals. band 41 might interfere with sband/wifi which maybe why the r850 wont transmit b41 without external antenna.

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