Home | Community | Message Board

MushroomCube.com
This site includes paid links. Please support our sponsors.


Welcome to the Shroomery Message Board! You are experiencing a small sample of what the site has to offer. Please login or register to post messages and view our exclusive members-only content. You'll gain access to additional forums, file attachments, board customizations, encrypted private messages, and much more!

Shop: Bridgetown Botanicals CBD Concentrates   Kraken Kratom Red Vein Kratom   Unfolding Nature Unfolding Nature: Being in the Implicate Order   PhytoExtractum Kratom Powder for Sale

Jump to first unread post Pages: 1
OfflinePsilosopherr
A psilly goose
Other User Gallery


Registered: 02/15/12
Posts: 12,278
Last seen: 1 month, 9 days
My plan to make a homemade cell signal booster * 1
    #27420466 - 08/09/21 12:33 AM (2 years, 5 months ago)

Edit: Looks like homemade signal boosters with amplifiers might be illegal, but passive ones w/o amplifiers (discussed a few posts below) are a viable option. Probably doesn't work nearly as well but we'll give it a go

I'm in a metal building and use a hotspot device for internet, my cell signal is good outside but bad inside, so my internet is slow. Retail cellphone signal boosting devices cost hundreds of dollars but sound pretty simple, think I might make one myself.

It sounds like its just an exterior antenna wired to an amplifier wired to an interior antenna. Picks up outdoor signal, boosts it, broadcasts it indoors.

I'm in research phase right now but this sounds like a sweet project. Thought I'd post to get potential advice from people who know electronics, and just to spread the idea around to those who might be interested


I'm gonna edit in links/useful information tidbits below for myself and for future lurkers. You can never be sure about the accuracy of the internet but I'm gonna talk this through with an electrician I know



Quote:

The tricky part is orienting the exterior antenna for the strongest signal. When ordering your parts for a homemade cell phone signal booster, order a “patch cord” that fits your brand and model of phone. Plug one end into your phone and the other directly into the antenna. Every newer phone has built-in electronics that’ll identify signal strength as you turn the antenna and anchor it. The directions that come with the amplifier will help with this.




db/dbm is a measure of signal strength
Quote:

Keep in mind that because dB and dBm are logarithmic, the normal ways we are used to thinking about magnitudes no longer apply. For example, a negative 30 dBM signal is twice as powerful as a negative 33 dBm signal. And a negative 84 dBm signal is four times as powerful as a negative 90 dBm signal. The signal strength doubles every three dB.






https://www.familyhandyman.com/project/how-to-get-better-cell-phone-reception-at-home/
https://www.instructables.com/DIY-2G3G4G-Wireless-Cell-Phone-Signal-Booster/


Edited by Psilosopherr (11/15/21 03:14 AM)


Extras: Filter Print Post Top
OfflinePsilosopherr
A psilly goose
Other User Gallery


Registered: 02/15/12
Posts: 12,278
Last seen: 1 month, 9 days
Re: My plan to make a homemade cell signal booster [Re: Psilosopherr] * 1
    #27420511 - 08/09/21 01:54 AM (2 years, 5 months ago)

I found a function on my hotspot that gives you a live value of how strong the signal is and found that by moving it to a different window I get an extra ten dbm and more snr. According to the figure above, I just tripled my internet speed :lol: A great start, but I'm guessing an amplifier could improve things even more

this is fun to read about. Radiowaves are magic

edit: oh no
Quote:

"The weBoost system, for example, requires a minimum signal strength of -95db or stronger (the closer to zero, the stronger the signal). If the signal isn’t strong enough, the booster won’t work in your home."




My signal maxes out at -105db outside...maybe it'll improve when the clouds clear. Still you'd think an amplifier would amplify a signal regardless so long as its there. Even if it only got me down to 105db that'd be three times faster than what I have now.

Quote:

Since cell phone boosters require some signal in order to boost it or multiply it many times, there needs to be atleast "poor" or "weak" signal outside where donor antenna can be placed. Therefore, you can deduce from this that the minimal amount needed must be atleast within -101 to -109 dBm if on 3G network, and within -111 to -119 dBm on 4G / LTE network.


aha!


Edited by Psilosopherr (08/09/21 02:48 AM)


Extras: Filter Print Post Top
OfflinePrimeMulch
Extreme Sheep Herder
 User Gallery


Registered: 03/21/19
Posts: 52
Loc: Lithuania
Last seen: 1 year, 26 days
Re: My plan to make a homemade cell signal booster [Re: Psilosopherr] * 3
    #27532308 - 11/06/21 09:48 AM (2 years, 2 months ago)

Well friend I hope you haven't given up.
There is such a thing is a passive booster. What you do is find out what frequency your cell phone uses. It depends CDMA, GSM, LTE, 3G, 4G, 5G. Do a little research.
Then buy a length of coaxial cable. Any kind or brand.
Use this calculator:
https://m0ukd.com/calculators/quarter-wave-ground-plane-antenna-calculator/
Build the center bit out of coax, build the outside legs out of the shielding of the coax.
Have it outside, on a wooden pole either on the ground (where you have great reception) or on the roof.
On the inside, do the same thing but upside down.

Seal the outside coax with silicone sealant. You're in a world of trouble if water gets inside the cable.

If you are within a few feet of the inside coax you will see a jump in signal.

This is the easiest and cheapest way to increase your indoor signal diy style.

Any other method involves creating a bidirectional amplifier.


Extras: Filter Print Post Top
OfflinePsilosopherr
A psilly goose
Other User Gallery


Registered: 02/15/12
Posts: 12,278
Last seen: 1 month, 9 days
Re: My plan to make a homemade cell signal booster [Re: PrimeMulch] * 1
    #27543787 - 11/15/21 03:12 AM (2 years, 2 months ago)

Thanks so much man, I had given up because I thought an amplifier was necessary. So the two antennas don't need to be connected usually for that passive setup? Because my whole problem afaik is my metal walls blocking signal from outside, in my situation i'm guessing I'd need to connect them. Suppose I could put one antenna on the roof and run cable through the roof to the indoor antenna.

I use a hotspot for internet so I'm more interested in boosting both 2.4 ghz and 5ghz 4g lte. I'll have to look up what my phone uses, might as well boost em all. That calculator you linked suggests radials and vertical elements of 1.4 cm and 1.6 cm for 5ghz, awfully small

Any idea what kind of boost you get from such a setup? Can't be near as much without an amplifier eh? I dont need much more to be able to use my cellphone somewhere other than right next to the window


Edited by Psilosopherr (11/15/21 03:18 AM)


Extras: Filter Print Post Top
OfflinePrimeMulch
Extreme Sheep Herder
 User Gallery


Registered: 03/21/19
Posts: 52
Loc: Lithuania
Last seen: 1 year, 26 days
Re: My plan to make a homemade cell signal booster [Re: Psilosopherr] * 1
    #27551052 - 11/20/21 11:35 AM (2 years, 2 months ago)

An active amplifier is the way to go, and will be the most expensive.
Illegal in some of Europe (because if you know what you are doing you can be very naughty).
If you go that route, you will find you will have "full strength" signal inside. But that is a lie* (the devices don't know better), your "full strength" is what the amplifier can get from outside. So if you have two bars where you installed the outdoor antenna, it cannot do better than two bars inside (even if your phone shows you five). But the roof of your house probably has better reception inside (and that is what we are trying to do, move the good reception down).

In this case having metal walls really helps for having a signal booster. The more isolation you can get from the inside antenna to the outside antenna, the more "boosting" it can do without running in to the problem of oscillation.

Amplifiers want to oscillate. I used to build amplifiers and I would end up with excellent oscillators, I would build oscillators and end up with amplifiers. (only for HF High Frequency, I am not skilled enough to build my own for the Very High Frequency, or Ultra High Frequency VHF/ UHF, never mind where phones work in the Extremely High Frequency)

An amplifier will take the signal from outside and stick it inside for your use. Great right? But if that signal it puts inside for your phone is too large, it will leak outside. If it leaks outside it will get amplified again and re-injected into your home and this loop will continue until it has created a cell phone jammer. Most modern cell phone boosters have protection circuitry to prevent this from happening. What can you do with your install to prevent this from happening?
Distance. The larger the distance between input and output, the less output can get in to the input and create the loop.
Shielding. Metal will contain those signals.

Have the exterior antenna on side of the building towards the cell tower. Place a bit of metal on the other side so less signal from the inside reaches the outside antenna.
I understand this did NOT answer your question. I'm pretty high right now and will come back with a better answer.




Passive setup. Yes, the antennas are crazy small. This is actually an advantage for building and mounting these antennas. Less to waterproof. Less weight.
5Ghz is a very high frequency and it is unlikely your hardware store cheap coax (coaxial cable) will support it (rg-6)
https://www.w4rp.com/ref/coax.html

LTE is lower frequency. Around a GHz. So we can look at the link about. For 100 feet of cable it will cut the signal in half twice for 100 feet. The name of the game is to keep the coax as short as possible (while still going from a location of has signal to a location of no signal).

It will let you use your internet at places away from the window. BUT you will have to be within a few feet of the indoor antenna. The coax is just a pipe for the RF water to flow. The antenna is an interface for those waves to enter or exit. In a passive system you only have losses. So we must minimize those losses.

This field can get really deep (at least for my monkey brain). I would run tests and give you exact numbers for results, but my mind is kind of broken right now because I am loosing my job over vaccine mandates.


I am not sure what you mean by the antennas having to be connected. You have an outdoors antenna connected to the coax, this coax runs indoors, this coax connects to an inside antenna. You have seen the calculators, These antennas can be as simple as the coax being split. Those outer strands make the base. The center conductor sits straight up. Do the same thing inside.

You want a cheap and easy experiment to see if it will work for you? Just try it.
Buy some rg-6 from your local hardware store.

Use a knife to cut it to make the antenna to that calculator. Duct tape it to the roof outside. Duct tape it inside. Does it work? If yes, passive antennas will work for you. If not, the way it goes.


Extras: Filter Print Post Top
OfflinePrimeMulch
Extreme Sheep Herder
 User Gallery


Registered: 03/21/19
Posts: 52
Loc: Lithuania
Last seen: 1 year, 26 days
Re: My plan to make a homemade cell signal booster [Re: PrimeMulch] * 1
    #27551069 - 11/20/21 11:43 AM (2 years, 2 months ago)



This is an example picture. Have the coax run in the wall to out. Have the coax be split so that the braid of it is divided and sticks out like in the calculators. A bit of arts and crafts. Do the exact same thing on the inside. I did say this would only work for a few feet. Any more and you need to go active.

EDIT:

This guy does what I have described for a much lower frequency (larger antenna). But it works exactly the same for cell phones.


Edited by PrimeMulch (04/30/22 06:40 PM)


Extras: Filter Print Post Top
Jump to top Pages: 1

Shop: Bridgetown Botanicals CBD Concentrates   Kraken Kratom Red Vein Kratom   Unfolding Nature Unfolding Nature: Being in the Implicate Order   PhytoExtractum Kratom Powder for Sale


Extra information
You cannot start new topics / You cannot reply to topics
HTML is disabled / BBCode is enabled
Moderator: Ythan, Anno, Thor, Link, Seuss
728 topic views. 0 members, 0 guests and 3 web crawlers are browsing this forum.
[ Show Images Only | Sort by Score | Print Topic ]
Search this thread:

Copyright 1997-2024 Mind Media. Some rights reserved.

Generated in 0.022 seconds spending 0.007 seconds on 14 queries.