Motorola vs Chinesium radios for repeater build

[fijigreasemonkey]

Right on point here, many repeaters completely depend on a high quality duplexer or external filter to work, and even then they are compromised. Even some commercially made repeaters like the Yaesu Fusion DR-2X are compromised and could use some attention.

The picture below shows what I did to my DR-2X replacing the cheap internal RG-58 jumpers with double shield RG142 and silver plated connectors. Then a Corcom AC input line filter and lots of ferrites (white cubes) over internal cables between radios and controller, many that are unshielded. This repeater had some slight desense on a service monitor with no duplexer and the transmitter into a load when new. Now it’s desense free on a flatpack duplexer.



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BTW, my and probably your DR-2X spews out a lot of transmitter noise when operated on low power 5W and it interferes with its own receiver. Operating these at high power will probable burn up the transmitter, so the only viable power level seems to be mid at 20w. I pad that down to 5w using a high power 6dB attenuator then to a 5w in 85w out amplifier which works well and the repeater runs fairly cool.

That looks good.Sir do you still have those 66-88Mhz repeaters..I am in need of them.

 

[prcguy]

That looks good.Sir do you still have those 66-88Mhz repeaters..I am in need of them.

I had a couple of radios in that band and possibly a portable repeater, will have to check.

 

[SailorDan]

Appreciate all of the input.

prcguy - nice looking build

I have been convinced to go with a dedicated repeater for now. I picked up a VXR-7000 for about the same cost as cobbling together 2 radios. I do need to source a flatpack duplexer for it.

The Fiplex DCL4533A seems to be a direct match (dimensionally/performance) to the originally equipped VXD-60UD. I'm not familiar with the brand.

I have heard good about EMR and Celwave, but would need to source used and figure out tuning without a fancy spectrum analyzer.

Any thoughts on Bridgecom duplexers?

 

[prcguy]

Finished my two mobiles in a box repeater project today and got the fan installed drawing air diagonally across the radios and heat sinks. Running the transmitter for about 30min continuous gets warm but not hot, should be fine for occasional use. Also installed Anderson Power Pole input for mobile use and a folding carry handle on top. This has been more of a proof of concept thing using stuff I already had and I don’t think I would recommend using mobiles like this for a permanent high duty cycle repeater. If you already have the radios its not bad for a portable/temporary thing.

 

[JustinWHT]

Finished my two mobiles in a box repeater project today and got the fan installed drawing air diagonally across the radios and heat sinks. Running the transmitter for about 30min continuous gets warm but not hot, should be fine for occasional use. Also installed Anderson Power Pole input for mobile use and a folding carry handle on top. This has been more of a proof of concept thing using stuff I already had and I don’t think I would recommend using mobiles like this for a permanent high duty cycle repeater. If you already have the radios its not bad for a portable/temporary thing.

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Reminds me of the 2/6/10 meter Heathkit "Benton Harbor Lunchbox'" from mid-60's. 😁
Looks good!

Photo credit: Heathkit HW-29A "Sixer"

 

[fijigreasemonkey]

Well done sir..!

 

[fijigreasemonkey]

I had a couple of radios in that band and possibly a portable repeater, will have to check.

Any luck with repeaters for the requested band width sir-66-88Mhz..

 

[prcguy]

Any luck with repeaters for the requested band width sir-66-88Mhz..

Been on travel, will look today.