building a repeater out of two Kenwood TK-880

[Steve]

Hello everyone!

 

i'm looking to integrate a Kenwood TK-880-1 ver2 with a repeater controller.... I'm about to pull the trigger on a pair or 880s and just wanted to do a bit more research before i do.   On some other models like TK-805D, there is a way to open it up and solder some connections for the rx tx, ptt, tone, gnd, etc. (see link below)  I can't seem to find anything on interfacing those.... wondering if the front RJ-11 would allow a custom cable?  I'm going to most likely order a NHRC-3.1 controller so I'll have to make a custom cable anyway.  

 

Parts include:

 

Kenwood TK-880-1 ver2 40 watt (or Kenwood TK-840-1 25watt) - both inside the GMRS band.

 

NHRC-3.1 repeater controller

NHRC-Squelch controller

 

to be figured out later:

antenna tuned for GMRS

duplexer tuned for my channel

cables

 

I could also go with TK-840 - because i can also get a good deal on a pair of those. 

 

or maybe an older TK-805D because i found detailed plans on how to build the interface cable here:

http://www.repeater-builder.com/kenwood/pdfs/tk-805-wiring.pdf

 

I was looking to stay away from the 805 and 840 because the volume and ch knobs wear out, and become noisy.  The 880 has a digital volume control and more features, so i think it would last longer, and i'd get more life out of it.  plus, its a bit higher powered, not that i need that high of power anytime soon.

 

any experience connecting the 880's or 840s to a controller?  I'm leaning more towards the 880s, for a few $ more, the version 2 gives me 40 watts.  but i'm not sure i need all that power, so i hope there is a lower 10 watt option for normal use.  the 880 is hard to find details on, but i'll keep looking!

 

Steve

 

yes, i'm GMRS licensed.

[zap]

Usually stands for "Radio Service Software".

 

Software definitions.

 

KPG - Kenwood Software

CE - Vertex Software

RSS - Motorola's Radio Service Software, usually DOS based but there are some exceptions with the 1225, Quantar, MCS and a few others.

CPS - Motorola's Consumer Programming Software, all made to run in Windows.

CS - Icom's Software

[WQOJ953]

Got it and thanks again. I looked around for a forum last night but didn't come up with much. didn't have a lot of time to spend on it either. I'll keep looking today.

 

Thanks again.

[WQOJ953]

Also, I have found the accessory pigtail for the Kenwood TK-880 on line for 21 bucks.

[Steve]

yes, i was just going to tell you that i found them on ebay... you should grab a pair of them, they are hard to find, and it will allow you to just plug in without having to solder directly to the board.     You'll also need the plugs for the other end.  I might have already posted which parts they are on this thread.

 

as for my updates, i'm just having trouble finding the time right now to do this...  but i do want to build a portable system with these. I just need to make the cables (i have all the parts for them) and assemble the radios into a case like an old plastic tool box.  It should be some what water proof but allows air flow and cooling.  That's the key.    These radios will get plenty hot in the sun before they even kick on. 

[Steve]

Sorry, guess I need to check my notification settings. Just saw y'alls replies. I have not had a chance to look at it again. I will double check active low keying though. 

 

Steve this particular one will go in a permanent location. If it works, I'll build another in a go box. We have plans to create a battery system with solar panels and multiple outputs. 

yes, that's exactly what i want to do.  make a go box with these... i think cooling is going to be a challenge.   the battery and solar charging is trivial, you just buy the kit online to charge.   mounting and connecting it all up is the hard part.

[Steve]

 

 

I'm started reading that I could just make a RICK cable for these radios to just jumper across. 

i forgot what a RICK cable is, is that where you just connect the front RJ45 plugs into each other?  if that was possible, i'm not sure i would want to do that... yes ,its simple, but i rather spend a little more time and get the controller in there for all the extra features you'd get.  I figure if i 'm going to spend that much time and money on this, i want to have it fully functional. 

[zap]

Repeater Builder has a good write up on off grid repeater systems.

 

The rick connects through the rear accessory connector on 16 pin radios. Bit more of a pain if we are talking about using the masked logic boards with 5 pin accessory.

 

Sent from my iPhone using Tapatalk

[quarterwave]

I always skipped the RICK (it was just another way for M to get another $300 out of a customer) and built my own, or used one from MRE1032 (MRE Direct) on eBay. I run one of those on a couple of M208's right now, it has a delay and adjustable audio. You can also use a 5 Pin for the TX as they use the RJ45. I think the only issuse using a 5 Pin for RX was getting COR to the RJ45. I didnt' want to modify the radios, so I never did that specifically. 

[WQOJ953]

Thoughts on the ID-O-Matic IV controller?

[WQOJ953]

I just picked up 4 KCT-19 cables for $14.95 each and a TK 880H-1 for $75.00 complete with the bracket mic and power cord. Now I need to find a diagram for joining the two radios and maybe a controller. I have a duplexer already and the antenna.

[KimOlarte]

How's your project coming along ? Stuck?  

[Steve]

KS- thanks for checking in...  its been a while since i have posted, not much has changed... still playing with my GR1225....   the Kenwoods are sitting on my desk. I have been playing with my other repeater and slowly realizing that i dont have a good location for it. So i'm working on trying to find a location (and antenna), and then i will be excited to finish the build.  I'm at the point where i just need to connect all the wires, then test it out...

 

I will update when i have more news. 

[KimOlarte]

I'm looking through my paper works, to see if there were any dealers or customers making a repeater with two TK-880's from what I remember is that there's a diode or a few that needs to be changed and the wiring from Radio 1 to Radio 2 through the rear port connection to each other. 

[WQOJ953]

I have some paperwork that mentions removing some diodes as well. I've been told you may not need to do that if you have the software and can program the KCT-19 cable to do what you want it to do. I'm not sure if that is true or not, it's all Greek to me.

 

I haven't had any time to work on my TK-880 repeater. Purchased a new house and everything is still packed away in boxes.

[Steve]

Comet CA-712EFC just arrived.  i will try and get that set up on my roof for testing before winter.  i will compare that to my Ed Fong antenna.  However, i'm sure the cable will make a bigger difference.  I'll go from 75ft of RG8x to maybe LMR400, i have to find the shortest path to the antenna by moving the radio upstairs, and then order some cable.   This is def a winter project for me.

[zap]

If your budget allows for hardline (even 1/4") you may look into some heliax.

 

 

Sent from my iPhone using Tapatalk

[gortex2]

Comet CA-712EFC just arrived.  i will try and get that set up on my roof for testing before winter.  i will compare that to my Ed Fong antenna.  However, i'm sure the cable will make a bigger difference.  I'll go from 75ft of RG8x to maybe LMR400, i have to find the shortest path to the antenna by moving the radio upstairs, and then order some cable.   This is def a winter project for me.

 

Dont use LMR400 or youll be asking for trouble. If this is a slow project wait and get some heliax.

[Steve]

Dont use LMR400 or youll be asking for trouble. If this is a slow project wait and get some heliax.

okay, I'm looking around at what i need... looks like 25 to 50 feet in total i will need.... at that short length, is it really worth going heliax? Looks like i can get 50ft of LMR400 for around $80 with N connectors from http://www.amazon.com/Antenna-Times-Microwave-Transmission-Connectors/dp/B005DVAA9W/ref=sr_1_4?ie=UTF8&qid=1447097763&sr=8-4&keywords=LMR400.  What is the trouble i will get into besides overall signal loss per 100 ft specs? 

[Steve]

how about 50 feet of RG213 ?  I might be able to cut that distance in half and use 25 or 30 feet if i move the radio into my bedroom closet and feed the line a different path.  http://www.amazon.com/MPD-Digital-rg213-50-pl259-Low-Loss-Connectors/dp/B004TBE17O/ref=sr_1_2?s=electronics&ie=UTF8&qid=1447099104&sr=1-2&keywords=RG213+50+feet

 

after looking at the losses....

 

http://www.w4rp.com/ref/coax.html

 

it seems LMR400 would be a lot better than RG213 .....

 

how about 30 or 40 feet of LMR600? - or 400....

 

I'm going to double check the length and order soon, anything is better then 75 feet of RG8X that I had.

[zap]

how about 50 feet of RG213 ? I might be able to cut that distance in half and use 25 or 30 feet if i move the radio into my bedroom closet and feed the line a different path. http://www.amazon.com/MPD-Digital-rg213-50-pl259-Low-Loss-Connectors/dp/B004TBE17O/ref=sr_1_2?s=electronics&ie=UTF8&qid=1447099104&sr=1-2&keywords=RG213+50+feet

 

after looking at the losses....

 

http://www.w4rp.com/ref/coax.html

 

it seems LMR400 would be a lot better than RG213 .....

 

how about 30 or 40 feet of LMR600? - or 400....

 

I'm going to double check the length and order soon, anything is better then 75 feet of RG8X that I had.

The trouble you can run into is caused by the construction of LMR cable. It achieves its low loss by using a foil shield in addition to the braided shield. This has been known to cause some harmonics from the dissimilar metals creating noise on the receive.

 

 

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[Steve]

just noticed on amazon.... What is length measured in "Times" mean? I've never seen that.  The company name is "Times" but why is that in the length?  I assume its "feet" long.  I tried google searching but keeps returning results for measuring time as in the clock, minutes, seconds, etc.

 

http://www.amazon.com/Times-Microwave-LMR400-N-male---N-male50ft-Connector/dp/B000LVAKTO/ref=sr_1_1?ie=UTF8&qid=1447108689&sr=8-1&keywords=LMR400+50ft+N

[Steve]

The trouble you can run into is caused by the construction of LMR cable. It achieves its low loss by using a foil shield in addition to the braided shield. This has been known to cause some harmonics from the dissimilar metals creating noise on the receive.

 

 

Sent from my iPhone using Tapatalk

Ah... I remember you talking about that before.

[PastorGary]

Amazon has some issues with non technical persons editing and publishing technical descriptions.  Some of their tech data can be misleading if you don't look very carefully and reason logically as to exactly what they are trying to say.

 

If in doubt, go directly to the manufacturer's website for tech data.

[zap]

Hutton Communications and Tessco are where I would buy feedline from.

[ASRM]

As others stated, go with hardline/heliax. Depending on the length, have you tried a local radio shop? Lengths under 100-75 feet can be had pretty cheaply. 

 

I was told to steer away from LMF on another site, was some of the sagest advice I got