Portable Club repeater

Groucho

Groucho

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I was just wondering what folks actually thought about this idea.

I had imagined constructing a basic trailer with a simple telescoping ROHN tower that could be raised to 30-40 feet when upright; a simple repeater using maybe two mobile rigs coupled together with a duplexer and controller; battery power with solar charging and backup.

Something like this.

Or this.

Or This?

Thoughts? I think we could design and build just about all of the parts that these two examples use. We could also make it so it could be used on Tim's place, and only move it to go to Moab.

I might be dreaming, but why not dream?
 
DaveInDenver

DaveInDenver

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I like the mil style crank up. That could pretty easily be integrated into the parts trailer, just bolt it on the side. Like you say, a couple of 2m radios, a duplexer and a controller. It wouldn't take up much space. Actually a generator would take up more space than the station itself.
 
Uncle Ben

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DaveInDenver said:
I like the mil style crank up. That could pretty easily be integrated into the parts trailer, just bolt it on the side. Like you say, a couple of 2m radios, a duplexer and a controller. It wouldn't take up much space. Actually a generator would take up more space than the station itself.
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Do we need two radio's or just trade the 7800 in for a 8800? I see no reason this couldn't be a reality. Somehow I see Michelle being a little more tolerant of a 40-50' tower out of her sight on the property vrs the club trailer in the driveway! Break down whats needed and I'll do my part in snooping around! A couple of group 31 deep cycle batts would last quite a while and with a solar panel trickling in some relief I bet they would last a week with out recharging! Heck while were dreaming how about a internet dish and broadcaster in the trailer also? That would work for both Campground internet access and IRLP!
 
DaveInDenver

DaveInDenver

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Uncle Ben said:
Do we need two radio's or just trade the 7800 in for a 8800?
Click to expand...
No, can't use a 8800 for this. We've touched on this subject a few times about the dual VFO radios and the x-band repeat function. Without a self ID and a remote control feature, doing a repeater is illegal. It's skirting the law doing it in the back country, particularly if you leave the truck without someone in front of the radio. You could do a U->V range increasing x-band with the 8800 and just periodically announce that you are KD0CLY on a HT at 446.000 through a repeater to 146.520 (or whatever). But not being physically in control of the mobile radio is technically illegal.

But setting up a real repeater without the ability to have it give its call sign every 10 minutes (that's the Morse you hear on most repeaters) and being able to shut it down would be bad. You don't have to station a ham in front of a repeater because the repeater controller has the ability to shut down the transmitter by phone or over the radio with the DTMF keys. That is not possible with the 8800 or most end user level radios. So you'd need two mobile radios and a controller.
I see no reason this couldn't be a reality. Somehow I see Michelle being a little more tolerant of a 40-50' tower out of her sight on the property vrs the club trailer in the driveway! Break down whats needed and I'll do my part in snooping around! A couple of group 31 deep cycle batts would last quite a while and with a solar panel trickling in some relief I bet they would last a week with out recharging! Heck while were dreaming how about a internet dish and broadcaster in the trailer also? That would work for both Campground internet access and IRLP!
Click to expand...
The rest of this stuff is all doable. A 50W radio on TX draws about 8 to 10 amps. So figure the complete load would be like 15 to 20 amps with another radio on RX and the controller. I think running on battery is OK with a decent solar grid (say about 300 watts) for a portable, temporary repeater. If it was semi-permanent repeater, then I think being able to plug it in would be better.
 
nakman

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Yes, the club trailer probably wouldn't fly, I had it for a couple weeks when we first got it and it wasn't all that popular.. she seems to have gotten used to Patrolman's trailer though :).

But as long as the trailer has some good clearance, we can get that dude nice and tucked away back in the woods. I can only see the first of the three links above and tha one is too low, I presume the others are more military style? And as long as we have it properly grounded so there's no lightning danger or interference with the tv in the house, should be fine. But maybe wait until the third Ham class before you guys let her in on this little master plan here.. ;)

And I don't think one 8800 would really cut it, because you really need the duplexer in there to amplify, right? Two 2800's and a duplexer is what's in my head, but I honestly don't completely "get it." I'm sure Dave and/or Nathaniel can break it down though.


edit: and I see Dave types faster than me.. but running a long extension cord out to it is the least of our constraints here.
 
Uncle Ben

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nakman said:
Yes, the club trailer probably wouldn't fly, I had it for a couple weeks when we first got it and it wasn't all that popular.. she seems to have gotten used to Patrolman's trailer though :).

But as long as the trailer has some good clearance, we can get that dude nice and tucked away back in the woods. I can only see the first of the three links above and tha one is too low, I presume the others are more military style? And as long as we have it properly grounded so there's no lightning danger or interference with the tv in the house, should be fine. But maybe wait until the third Ham class before you guys let her in on this little master plan here.. ;)

And I don't think one 8800 would really cut it, because you really need the duplexer in there to amplify, right? Two 2800's and a duplexer is what's in my head, but I honestly don't completely "get it." I'm sure Dave and/or Nathaniel can break it down though.


edit: and I see Dave types faster than me.. but running a long extension cord out to it is the least of our constraints here.
Click to expand...

Club already has a 7800 correct? So we just need a power supply antenna, 2800 and duplexer?
 
Groucho

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The 8800 won't work for one important reason--X-Band repeat works in just that way:Cross-band or VHF to UHF. There is no opportunity to do a VHF to VHF Repeat because of the lack of duplexer to accomplish this.

Therefore, the "poor man's" repeater is actually two single VFO(Variable Frequency Oscillator) radios hooked together. One is a dedicated reveiver, the other is a dedicated transmitter(and sometimes they can be a dedicated PITA:D if they malfunction. This is what Dave was mentioning about being able to turn them OFF remotely if a problem arises.).

Imagine the two radios stacked on top of each other. One is on 145.145, which would be the dedicated transmit. The other is on 144.545 which is the dedicated recieve. The speaker output of the recieve radio goes into the microphone input of the transmit radio. Each antenna connection goes out about 12 inches to what is known as a duplexer. Then out of the duplexer goes one coax feedline to the antenna. Theoretically, when the receive radio receives a transmission on the receive frequency, the radio would put that as audio output to the transmit radio's audio input, where that radio would then transmit that audio on the transmit frequency. This is all done using the same antenna.

Now, the duplexer prevents the receive radio from being nuked by the transmit radio's power when the transmit radio is transmitting.

One thing that Dave mentioned that I intentionally left out of the example above is the controller. This piece of equipement does several things. It is responsible for the CW ID, as well as performs the task of being the "operator" in the theory of the Remote Operation. This does the "keying" of the transmit radio when the receive radio recieves a transmission. If something goes wrong with the repeater, the controller can shut things down(I don't know all about how they do it) so that there isn't a carrier signal being transmitted 24/7, burning up the radios, etc. These things all keep the station in the "legal" so that it may operate.

Aside from a power supply(easy), an antenna(which the club already owns) and a tower(which we are confident we could build), that is all that would be needed to have a working repeater. One Yaesu FT2800 would be $125. Duplexers are reasonable, and a controller is around the $250-$500 range if I have read my tea leaves right. I think we could be in business with either a portable of semi-permanent repeater station for less than $1000.
 
Convert

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This all looks very interesting and doable I like the military tower
 
nakman

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Alright, which one of you guys leaked? :rant: bastids..
 
wesintl

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:lmao: :lmao:
 
corsair23

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Uncle Ben said:
OUCH! :eek: Luckily, V-Day is coming up soon....use the day wisely my friend! :bowdown::Princess:
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x2

You should have seen the look in her eyes when someone mentioned something about a tower and keeping it from falling into the tub :eek: :hill:
 
Red_Chili

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I thought she took it well. Did I see enthusiasm when I suggested she could just leave her dinner out and it would heat itself? Yep, I'm sure of it.
 
T

Tramontana

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Oh, I don't know about that...

Red_Chili said:
I thought she took it well. Did I see enthusiasm when I suggested she could just leave her dinner out and it would heat itself? Yep, I'm sure of it.
Click to expand...


...I was sitting two chairs away, and I'm pretty certain I heard teeth nashing, and something like "He is soooo busted" muttered under her breath?! :rant:
 
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