HF receiver Eaton 750

bearcatrp

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what can folks tell me about this receiver? Been on the hunt for a receiver and about to get a icom 7300 but saw a post that has my attention on this receiver. I tried to look up the external antenna connection but can't find much about it. How good is this radio? Thanks.
 

WA8ZTZ

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The 750 has external antenna connections for LW/MW on the rotating ferrite bar atop the radio. There are two 50 ohm BNC antenna inputs on the right hand side of the radio, one for SW and the other for FM/VHF. There is also a hi Z set of terminals for SW at this location as well as a Internal/External antenna switch.

The radio is excellent for casual listening... very intuitive, easy to use. It was reviewed in the April 2021 QST.
It really cannot be compared to the 7300... two different radios entirely.
 

ka3jjz

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Other reviews found by Google





Mike
 

bearcatrp

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Thanks. Will check them out. Am presuming it doesn't have filters like in a ham radio or something like the R75 I am looking at. Looks to be a solid radio from the few reviews and you tube videos I have looked at so far. As much as I want the 7300, and with christmas around the corner, will pass on the 7300 for now. Can still get the R75 thats available.
 

MTScannerNut

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Check out eBay and the classifieds over at qrz.com for an R75.

I just picked one up on eBay for $400 that looks and functions like new. I was surprised that it receives almost as well as my R8600. There are certain things I actually prefer over the much more expensive R8600.
 

Patch42

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Found someone selling a R75. I jumped on it.
If I might suggest, pick up a decent quality 13.8V (nominal 12V) regulated power supply and ditch the Icom power supply. The included supply pushes the voltage much higher than needed and will cause the radio to die prematurely. I think I paid about $40 for the Pyramid model I bought. I got one that provides more Amps than I need for the R75 so I'd be able to hook up additional equipment down the road. I cut the DC plug off the included power supply and put Power Pole connectors on both cut ends so I can easily reassemble it if I should need to. Then Power Pole connectors on the leads wires to the Pyramid supply. Saved me having to find the proper power connector for the radio.
 

MTScannerNut

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I agree on the power supply. I tested the stock power "brick" and it’s putting out 20v with no load. Under load I’ve read it’s around 17v; way too high.

I’m running mine off my Alinco power supply along with my R8600 at 13.8v.
 

Patch42

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I think that's the Icom stock power supply. I'd seriously consider a decent quality regulated 13.8v supply. Your R75 will thank you.
 

GB46

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I cut the DC plug off the included power supply and put Power Pole connectors on both cut ends so I can easily reassemble it if I should need to. Then Power Pole connectors on the leads wires to the Pyramid supply. Saved me having to find the proper power connector for the radio.
I'm still using the power cord that came with the original adapter, because I couldn't find a plug that matched. I cut off the adapter and stripped the conductors on that end to attach them to the Pyramid supply's screw terminals. Remembering which conductor is positive isn't easy, because the insulation is plain black on both conductors, so I wrapped a red and white twist tie around the positive one in case I need to disconnect it from the supply in the future. This is kind of like the old trick of tying a string around your finger as a reminder ... and hopefully not forgetting what it's supposed to remind you of. :)
 

GB46

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I think that's the Icom stock power supply. I'd seriously consider a decent quality regulated 13.8v supply. Your R75 will thank you.
Yes, that's what I had to do. I can't imagine why Icom included such a horrible power supply with such a good radio. They even state on page iii of the manual that switching supplies can cause RFI. Instead of recommending the purchase of a good linear supply, however, they list some workarounds, such as an AC line filter or keeping the supply as far away from the antenna as possible. The latter never helped in my case, because the RFI was fed through the power cord directly into the radio's power jack.
 

bearcatrp

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The person I am buying it from had a AD55A or AD55S to choose from. But if the one I selected is still a bad idea, will order a external power supply. Not sure if both of these power supplies are from icom.
 

MTScannerNut

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Neither are very good.

AD55A is regulated, but puts out way too high a voltage (17v+).

AD55S is a switching supply, still puts out 15v, and is known to generate lots of noise.
 

mbott

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AD55S is a switching supply, still puts out 15v, and is known to generate lots of noise.
When I purchased my first R75, I ran into the noise issue with the AD-55S. Took the radio and the power supply into Universal and we hooked it up there. Quiet as a church mouse. Wasn't that way at home, so I'm *assuming* it was an interaction between the mains and the AD-55S that caused the noise. I'm using an Astron RS-12A with the R75 now. It is also powering several other pieces of equipment.

My original Astron was the RS-4A.

--
Nike
 

Patch42

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I'm still using the power cord that came with the original adapter, because I couldn't find a plug that matched. I cut off the adapter and stripped the conductors on that end to attach them to the Pyramid supply's screw terminals.
That's fundamentally what I did for exactly the same reason. I had a known proper connector on the radio end so I used that. Only difference is I put Anderson Powerpole connectors on the cut ends so I could easily put the original power supply back in use. (This was mostly in case I ever wanted to sell the R75. Figured a professional looking splice would look better for resale.) Then I put spade lugs on another piece of heavy wire and attached Powerpole connectors to the other end of that.

I also had fantasies of eventually hooking the Pyramid to a Powerpole power distribution box so I could run multiple devices off it. I figured, worst case, I have a solid, professional splice of the power cord that can be easily reattached to the original PSU. Best case I'm well situated for future growth.

What I did is just a fancy version of what you've done. How's the R75 working? Have you figured out the twin-passband control yet?
 

bearcatrp

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Radio is here. Did use the included power supply briefly to test it out. Put it away until I decide which astron power supply to get. The RS 12A looks like it will do the job.
 

GB46

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What I did is just a fancy version of what you've done. How's the R75 working? Have you figured out the twin-passband control yet?
It's still working fine after 21 years, and I could hardly help figuring out the PBT after all that time. It's one of the R75's most useful features. I don't get a lot of interference from adjacent signals here, but it helps me lower the noise floor somewhat. I also use it as a tone control on SSB voice signals, especially in LSB, as there's not quite enough treble in that mode compared to USB, where I can just leave the PBT in the center. For LSB I often find it necessary to rotate the outer dial as much as 45 degrees clockwise. It doesn't help on AM signals, however, and the international broadcasters come over pretty muddy at times. I always listen with earbuds, but tend to need more treble response due to some age-related hearing loss.

In case you missed my saga of the dying R75 in older threads, there was nothing wrong with the radio. I was overlooking the internal fuse, which wasn't properly seated in its holder, causing the radio to lose power and shut off intermittently. That was my fault, and very easy to correct by snapping the fuse in properly.

As for those power connections, I never plan to sell the radio, and I wouldn't be able to include the original power supply anyway, as I threw that out 19 years ago. That's because I had accidentally shorted the thing out, rendering an almost useless supply completely useless. Poetic justice! :)
 
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