Build your own 2 meter tactical repeater from Bendix King HT's on the cheep!

[@MadMaxTrac]

There are other HT's that can be configured in a similar matter. I picked the BK's to use because their circuitry is designed so you can simply modify them to work in this way, they have actual 50 ohm antenna connectors, and they will easily run in the 12-13.8 VDC range.

[@BadMuther]

That's an awesome idea, thanks for showing that. I'm an ex-SoCal born and bred. BK's are awesome radios for Jon-techies like me.

[@TXRottguy]

Great video and good looking setup, looks like I have a new project! I've been using MPH 5142s as scanners for years. The BK MPH/LPH and EPH radios are great to have around!

[@MadMaxTrac]

No, I am jumping between points on the PCB of each radio, the only passive component between the two radios other then wire is a small cap to filter the DC from the audio jumper. The PDF explains this.

[@CBKillas]

Pretty cool. Did this with two FT-2800's. 3 batteries, Small solar panel. Still works too. Not sub $100, but WELL under 3. Put it on the mountain here, 100 mile coverage. Oh yeah, and a simple nPn transistor...

[@johnhess351]

Your math on calculating the voltage of 9 parallel AA alkaline is correct, however that is the open circuit voltage. Any useful current draw will instantaneously drop the voltage to 13.8 and probably less.

[@MadMaxTrac]

I will work with a regular 600K split, if the antennas are far apart, but I usually run an odd split over 1Mhz. Usually something like 144.3XX in and 146.5XX out.

[@GUERRILLACOMM]

Nice tinkering, good job.

[@rowdyraider556]

You may like a project I'm working on right now. Working on using a Raspberry Pi and freeSwitch as a controller (it can do announcements, autopatch, callsign in morse (or voice recorded sound off). Have a surplus GM300 and F221s so I'd like to have a cross band so I can play on the Saltgrass system in Lubbock when I'm outta HT range with my FT-2900 in my car. Also setup for two Baofeng UV-5Rs similar to your setup but with a 5V headless RPi as a controller.

[@MadMaxTrac]

That sounds awesome, do you have any videos or a site with instructions?

[@MadMaxTrac]

hmm, I work in the ammo industry and we refer to that size can as "50 cal" can because that's what initially that can shape was designed for. These days the military uses "50 cal" and "30 cal" cans for 5.56. Even the "Fat 50" can is used for 5.56 SAW ammo. Even though this particular can contained stripper clips of M855 ball ammo I assure you it is what is universally known as a "50 Cal" can.

[@zacharylacewilliamson1578]

Love the design here! Had a question for you. How is it that the transmitting radio doesn't overload the receiving radio when the repeater is in use? Is it just due to the fact that you have separate RX and TX antennas that are spaced a fair distance apart?

[@wilXwyane]

So did you just plug a speaker cable from the receiver radio into the mic port of the transmit radio? Because uv seen those repeater-tone controllers on eBay but it it doesn't look like you used one of those.

[@KeithKenobi]

I have some EPH510SL radios and the boards are different for bringing out COR, audio, PTT etc. Are some of those connections on the 6-pin programming socket?

[@MadMaxTrac]

Yes, one is hosted on the original site, one on my site, just as a backup.

[@blinko656]

I was going to buy a Bendix King however some of the channels are scrambled. Is there a way to clear that, I don't think you can program over the scrambled freq. Mike Retired FF Cal Fire sub

[@MadMaxTrac]

I'm not sure. The old BK's you can just hand program, no scrambling.

[@craigpalmer6490]

I like the whole idea but two things a DOS computer? also I would like to use two Baofeng UV-5Rs .Ina comment below up mention this radio...please more info.Thanks

[@VolksPrepper]

There are many Bendix designations (LPH, MPH, EPH) with various model numbers of each. That said...why do you use this particular model and would the others be just as well suited for building repeaters?

[@MadMaxTrac]

Yes, I keep the antennas spaced about 20 ft apart.

[@nolandrake4261]

pro trick : you can watch series at Kaldrostream. I've been using it for watching a lot of movies these days.

[@prestondavid1530]

@Nolan Drake yup, I have been using KaldroStream for since december myself =)

[@jesseduncan1140]

@Nolan Drake Definitely, I've been watching on Kaldrostream for months myself :)

[@royalronan1418]

@Nolan Drake definitely, I've been using Kaldrostream for months myself :)

[@MartialArtsTutorialsFighttips]

Hello will this work or feed two other walkie talkie

[@MadMaxTrac]

That is actually a term BK uses because the repeater is small, quick to deploy, and designed to cover a local area. That said I should add some pic rails, QD sling mounts, and a bayonet lug;)

[@MadMaxTrac]

Yes, DOS Many old radios from the 90's have to be programmed in DOS, I guess you've never used Motorola RSS before. I'm not sure why you would want to do this with UV5r's when they cost more then LPH's, you would have to implement a power management system, a repeater controller, and in such close proximity the Tx radio would probably overload the front end of the Rx radio. I guess it could be done, but it's a totally different beast then this project.

[@gregorybirchfield4952]

Not seeing the link in here to build this. Any way to get instructions?

[@rogersmith9808]

Nicely done and quite interesting!!! (W9ING)

[@CPLBSS88]

the PDF links go to the same doc...?

[@Johnson2985]

what feed line are you using? I heard you say standard uhf connector, so are you using LMR400?

[@n9eerptr]

Did you do site noise test with this repeater when in operation??? ron

[@kronos202020]

@ MAdMaxtrac would you build a setup like this and sale it to someone who doesn't have the patience to take on this task.

[@toomanykats1]

i did this two broken EPH models. one didnt xmit and one didnt recieve. simple jumpering made a functional repeater.

[@MadMaxTrac]

They were really what was available at the time, there is no reason why any LPH / MPH wouldn't work, but YMMV;) Since the LPH are wideband only they are useless in the commercial market and much cheaper then the EPH and current BK's.

[@coxdpaul]

Any way to contact you. Building this have couple questions . Video uses 1 battery and pdf says 2? And another question. I can give phone or email

[@MadMaxTrac]

I'm not sure who you are talking to, I didn't make these videos, I'm just sharing them for the historical and educational purposes. I don't recommend anyone building their own firearm, it can be dangerous and illegal depending on where you live.

[@2012neely]

is there a way i can make a repeater for 27.mhz for a cb? i love projects

[@MadMaxTrac]

They are really easy to program: 1. Get the cable I mentioned in the video. 2. Download LMR.EXE (google around for it, it's easy to find) 3. Run the program on a DOS machine. 4. Follow the instructions in the links I linked to below the video.

[@berettamod961]

Is there an audio input for VOX on the LPH series?

[@MadMaxTrac]

no, not really.

[@timneshmathusudahnan461]

Hello sir.....I'm a final year engineering student and my project is to design a repeater based on walkie talkie system.....we only use one walkie talkie in this project which can receive and transmit the signal....Can you help how this project work and how to do this project

[@timneshmathusudahnan461]

Arduino board esp-12s Sq9mdd tnc OLED Components transistor, buzzer ,Capacitor , resistor, sui, led Walkie talkie this are the gadgets that we used to do my project...but dont have any idea how to do this and how my project works

[@2012neely]

thats how to build one....how do you use one how do you set it up? program something

[@texasprepper869]

what do you call the Anderson power pole bulkhead mount?

[@MadMaxTrac]

I'm not sure, they just have them in the store.

[@MartialArtsTutorialsFighttips]

thank you for your reply

[@1wasimtiger]

nice work

[@Jah_Rastafari_ORIG]

What's this "radio shack" of which you speak? Does not compute....

[@wilXwyane]

Sorry for the miss spelling and such, I'm on my tiny little phone. Thx

[@ThePiratemonkey68]

you should make a video of the audio

[@philshnieder9188]

Motorolas are best to use these days. M1225 by radius is small but robust..

[@MadMaxTrac]

tac·ti·cal adjective \ˈtak-ti-kəl\ A : of or relating to tactics: as (1) : of or relating to small-scale actions serving a larger purpose (2) : made or carried out with only a limited or immediate end in view Why is it "Tactical"? Because that's what the friggin word means. I'd like to see you run up the side of a hill with a Quantar and get it operational in 15 minutes. I'm guessing you have never worked on a wildfire where temporary repeaters are quickly set up as part of firefighting Tactics. If part of your Tactics for firefighting is having a quick deploy, portable repeater, that doesn't require mains power I'd say that makes it a Tactical Repeater. Maybe that's why they are called Tactical repeaters. www.cobaltequipment.net/index.php?option=com_content&view=article&id=156:bendix-king-tactical-repeater&catid=18:communications&Itemid=182

[@kg7tuo999]

You should have included "strategic" in your explanation. Tactical is the smaller operation and strategic is the "big picture". Tactical planning is what the small unit does in support of the larger (strategic) goals. Since the strategic goal was hunting, this was a means of supporting (i.e. tactical) that goal.

[@hubzcaps]

bruhgh need some of those radios

[@apostolicthruth805]

Yes.. audio would be cool

[@DaWorldOwner]

Damn Jamzalex you just got told! Maybe if you were listening to his words and trying to learn something you wouldn't have looked so stupid. =P

[@Subgunman]

Now do this with a air of Motoroni Sabre radios with DES encryption and use a couple of other like radios with DES and program them up to some DOT frequencies ( common low power licensed commercial frequency) for private COMMS. DO NOT USE ENCRYPTION ON HAM BANDS unless you use an APCO P25 standard with a non high security encryption standard where anyone can purchase and use freely. DES is not approved for Ham Bands.

[@MadMaxTrac]

This is actually pretty easy to do with Maxtrac and XTL mobiles.

[@pewtuber243]

RIP RADIOSHACK

[@trains11111]

just get the dc car power conector

[@pshl987]

graet 73

[@rumproast2000]

Nice setup! It's always nice to see the older commercial equipment getting new lives! I would just like to inform (or remind) everyone that FCC part 97 rules require that the repeater trustee (typically the owner) have the ability to remotely control the transmitter of the repeater via a control frequency above 222.15 MHz. Otherwise, the repeater must be able to turn it's transmitter off after 3 continuous minutes of transmission. I don't see any provision for this capability in your setup. Actually, there are several other important rules that should be adhered to regarding auxiliary stations (ie. repeaters) and I would recommend anyone planning on building their own repeater see the following page for more information: www.arrl.org/auxiliary-station-faq 73!

[@n3lee]

Radios are programmable with a time-out timer. The repeater operator must be able to control the transmitter -- there are many out there still on the air without controllers; although with the cost of DTMF modules; it's silly NOT to do it!

[@MadMaxTrac]

+rumproast2000 The transmit radio is programmed with a 30 second TOT.

[@zoolkhan]

why has everything to be "tactical" these days? I ate my breakfast with a tactical spoon!! uh yeah!! sound double as cool as ordinary spoon.. but gets the same amount of food into my tactical mouth .)

[@catsupchutney]

When I hear a guy use the word "tactical" outside the context of an ambush, I figure he sleeps in camo pyjamas.

[@zoolkhan]

Allan Peda when i was in the navy we got actually issued green underpants during our land-based bootcamp times :-) I found that hillarious.. drill seargent siad, now i can change my panties w/o giving away my position. I told him "this isnt the navy? i though i was gong to be on a ship, and i would probably change panties next to a steel wall with hopefully no holes in it through wich my ass could be seen..." .... lets just say i had to do a lot of jogging and "rifle gymnastics" that day. .... all the wannabe militia folks out there who are so very tactical. I can imagine that a real soldier would giggle or vomit each time a bloody civillian uses that word out of context.

[@michaelbodine6142]

there is a reasn you are only GIVEN ; ONE band; technology with BENDIX KING ; they also manufacture AVIATION BRAKES ;

[@kronos202020]

my you KZbin is jacked up sorry

[@kronos202020]

that's suppose to say " who doesn't " sorry

[@jamzalex]

i see you understand radios but you know nothing about ammo lol. 5.56mm is 223cal not 50cal

[@obeyconformtoday829]

You get what you pay for. Walki talkis will burn up with any talking longer than 5minutes. It may work. But agian its really has limitations