max your DX on the R-75

[ridgescan]

I got a bug to do a search on "getting the most out of my Icom R-75" and this gentleman had IMO the most helpful review-so I hadda come here and share one of his particular tips...kudo's to this guy!!
He states that if you are annoyed by overriding noise while listening to AM HF broadcasts, switch to SSB and tune the passband and low and behold-it really goes farther to stabilize the carrier AND cleans up the voice quality!! Very exiting-and greatly improves listening ability with weak stations. He describes other things you can tweek in the CW/RTTY modes too. Check him out
http://members.tripod.com/~bpadula/r75.html

 

[AB9IL]

Nice find. Indeed there's lots of DX to find in those ol' R-75s. They've always been pretty rough in the AM mode, and better for DXing when sideband is used.

There's another fellow over in Japan who took the bull by the horns, heated up his soldering iron and made some good changes in the audio. Here's a link:

http://210.155.219.234/R75E.htm

The biggies are :

1...reducing clipping on strong AM stations
2...raising the cutoff of the post-detector low pass filter to above 4 kHz
3...swapping the loudspeaker for a recently made unit from an Ipod

Whatwith all of the racket from HD stations in the AM band, one really needs to use sideband mode instead of AM.

 

[k9rzz]

Whatwith all of the racket from HD stations in the AM band, one really needs to use sideband mode instead of AM.

Definitely. Cobble up a loop antenna if you can. By using SSB and nulling the digital hash, I can get around most of that garbage across the band.

 

[jonny290]

The downside of AM reception with an AM detector is that you will get fading if either one of the sidebands OR the carrier fades out. This means that you are dependent on like 10 KHz of spectrum for a solid signal.

SSB, 2.8 KHz or so. Plus, you're generating your own carrier, so you aren't dependent on receiving the transmitter's carrier.

The downside is reduced fidelity and no 'lock' on the frequency, this is why you may have to twiddle the RIT a bit. I have found that even with as little as 10 HERTZ mistuning, voices sound unnatural.

If you want to find out exactly where to set your RIT for a natural signal, just switch from SSB to AM back and forth repeatedly, twiddling the RIT each time, on a station that is playing music. When the music is at the same key/pitch both in SSB and AM, you are 'on frequency'. On my 20 year old Icom, it is just about 1/2 notch left of center for LSB, about 70 hertz offset. I could get close to eliminating that by re-aligning the rig, but I'm lazy and don't have the time, so I just deal.

 

[ridgescan]

The downside of AM reception with an AM detector is that you will get fading if either one of the sidebands OR the carrier fades out. This means that you are dependent on like 10 KHz of spectrum for a solid signal.

SSB, 2.8 KHz or so. Plus, you're generating your own carrier, so you aren't dependent on receiving the transmitter's carrier.

The downside is reduced fidelity and no 'lock' on the frequency, this is why you may have to twiddle the RIT a bit. I have found that even with as little as 10 HERTZ mistuning, voices sound unnatural.

If you want to find out exactly where to set your RIT for a natural signal, just switch from SSB to AM back and forth repeatedly, twiddling the RIT each time, on a station that is playing music. When the music is at the same key/pitch both in SSB and AM, you are 'on frequency'. On my 20 year old Icom, it is just about 1/2 notch left of center for LSB, about 70 hertz offset. I could get close to eliminating that by re-aligning the rig, but I'm lazy and don't have the time, so I just deal.

Interesting stuff! So apparently this whole concept is news only to me here-you guys seem to be well familiarized with this style of DXing. Aside from the SX-88, this R75 is actually my first serious HF unit-all these years I've been running a Patrolman-9 from '74 and a '59 Transoceanic...hence how this was lost on me. Thanks for all your great info.

 

[SCPD]

I thought the best way to maximize DX on the R-75 was to take a hammer to it and buy a new radio!

 

[ridgescan]

I thought the best way to maximize DX on the R-75 was to take a hammer to it and buy a new radio!

Really? So what are YOU running? I would LOVE to hear what a fine HF unit YOU have that is so superior? I have seen you recommend Icom radios...you apparenly OWN an Icom tranciever-so why come here and bash the R75? Just feeling 'spunky'?

 

[ka3jjz]

Easy there folks. Let's turn down the sarcasm a bit here, and stay on topic 73 Mike

 

[ke5ldo]

You might want to go to the Yahoo group for Icom R-75. Look in the files sections for Phil's tricks for the R-75. Excellent suggestions and they work. KE5LDO

 

[WisconsinRailfan]

You might want to go to the Yahoo group for Icom R-75. Look in the files sections for Phil's tricks for the R-75. Excellent suggestions and they work. KE5LDO

That is a great Yahoo! group, lots of good info. Phil's tricks are great, also check out MyIcom8.doc, (not mine) which is also located in the file section.

 

[ridgescan]

Thanks you guys for helping enrich the DXing here.

 

[tonsoffun]

KE5LDO, thanks much for Phil's tips. I must have missed it when I was searching around there. His R75 cookbook is great!

Thanks again

Ron

 

[SCPD]

Really? So what are YOU running? I would LOVE to hear what a fine HF unit YOU have that is so superior? I have seen you recommend Icom radios...you apparenly OWN an Icom tranciever-so why come here and bash the R75? Just feeling 'spunky'?

You might want to look at the Icom IC-7000 - it is a transceiver than has incredibly good receive capabilities.

And BTW, I own a R-75 - so I can bash it all I want to!

 

[ridgescan]

You might want to look at the Icom IC-7000 - it is a transceiver than has incredibly good receive capabilities.

And BTW, I own a R-75 - so I can bash it all I want to!

o well in that case nevermind! How much cleaner is the recieve on your tranciever anyways and why the hell do they do that??!

 

[SCPD]

In fairness to the R-75, we are talking about 8 years of technological differences. It's really hard to describe the audio improvements but I would highly recommend finding someone locally (or head to your local HAM store) to listen to one. With even a random wire antenna, the DSP noise reduction is pretty remarkable.

Another reason to buy is that it's a transceiver - HF, 6m, 2m and 440. Can't beat that!

 

[k2rgf]

http://www.geocities.com/philsr75infocenter/
Some good info