Phelps Dodge UHF 4-Cavity Mobile / Repeater Duplexer, 50 W

[WSLL787]

I saw this unit on Ebay for roughly $90, I was wondering if this is worth the hassle / Expense? I am not familiar with this older style repeater. It would most likely be a joint/club venture to get this put up on the local tower as the club does not have a current GMRS repeater. 

 

[SteveShannon]

1 hour ago, WSLL787 said:

I saw this unit on Ebay for roughly $90, I was wondering if this is worth the hassle / Expense? I am not familiar with this older style repeater. It would most likely be a joint/club venture to get this put up on the local tower as the club does not have a current GMRS repeater. 

 

That’s not a repeater; it’s just a duplexer and it’s not tuned correctly for GMRS. 

[LeoG]

Looks as though it could be tuned to GMRS frequencies.  It's a flatpak duplexer and you could probably get a new one for about the same price, a bit more likely, and have it tuned for the correct frequency.

 

This might be the instruction manual for it.  It'll download a PDF file into you device.

https://www.google.com/url?sa=t&source=web&rct=j&opi=89978449&url=https://www.repeater-builder.com/antenna/phelps-dodge/pd-638-509-6.pdf&ved=2ahUKEwjH4NTd28WSAxUiMWIAHRqkArgQFnoECBYQAQ&usg=AOvVaw3LnA40L4KWPjTDecHV6Ce_

[LeoG]

It's made in the US, so that something.

 

Found this hilarious when I was searching it.

 

https://www.radiomuseum.org/r/phelps_dod_duplexer_638.html

 

[WRUE951]

Like Leo says, you can get a new Duplexer tuned to your specific frequencies  for a few dollars more..  You'll have to get that one professionally tuned and expect to spend $50-70 with shipping to get it done.  That puts you in the neighborhood of $200 bucks.  Check out the duplexers on BuyTwoWayRadios.com

You may want to study up on a better understanding of repeaters..   Learning is cheap and fun and defiantly never stop.  

[gortex2]

Phelps Dodge was a good duplexer built in the US. With that said I think they are asking a bit too much for that one. I have 3 or 4 in the garage collecting dust that I picked up for $25.00 each. 

[tcp2525]

On 2/6/2026 at 2:03 PM, WSLL787 said:

I saw this unit on Ebay for roughly $90, I was wondering if this is worth the hassle / Expense? I am not familiar with this older style repeater. It would most likely be a joint/club venture to get this put up on the local tower as the club does not have a current GMRS repeater. 

 

Personally, if i really wanted it, I would send the seller a message him you would buy it for $50 plus the shipping he's asking due to physical and unknown electrical condition. and ask him to send you that offer and you will complete the deal. You'd be amazed at how many great deals that can be had by doing this.