antenna tuner icom r-75

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cmed325

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i recently purchased this reciever,installed a 65 ft longwire in the attic,,will a tuner help this set up with reception such as an mfj?any suggestions to help the reception?
 

riverrat373

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I doubt that a tuner will increase the level of the received signal, but it may help in rejecting interference from stations on nearby frequencies.
 

ridgescan

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From what I gather, an antenna tuner needs at least 5-10 watts from a transmitter to activate it. I don't think we receiver guys can use one. You can get a "balun" which is kind of an antenna matcher.
 

ka3jjz

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For a receiver, needing any power is total baloney. A tuner needs no power whatsoever - what needs the power would be any of these fancy meters that reads reflected power and matches - neither of which a receiver would need to be worried about. A receiver would not be damaged (unlike a ham transceiver) by a matching problem - the antenna would simply perform poorly.

A balun is a transformer that changes a balanced input to an unbalanced one. It is not a substitute for a tuner - in fact some tuners have a balun in line with 2 posts to be used with feedlines like twinlead.

In general if you have a good outdoor antenna, having a tuner isn't going to get you much. Most receivers these days have front ends that are sensitive enough as it is. But if you are using a compromise antenna, an antenna tuner *might* help squeeze a little more out of it and make it seem to work better. But that is not a guarantee...

Baluns can also help limit common mode issues that can result in noise problems. We have a few articles linked in our antenna wiki if you're interested...best regards..Mike
 
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ridgescan

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Hi Mike-so you can actually operate an antenna tuner on a receiver?
EDIT-I see above you said it doesnt need power-that's cool. I must've only seen those "automatic" antenna tuners that use transmit to automatically tune for you.
 
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ka3jjz

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Absolutely - and you can forget about those automatic ones - for hams, they can be a godsend, but as a listener, they simply won't fly...

Here's a simple example of one that would be far cheaper than an automatic tuner, and would likely work just fine..

MFJ Enterprises Inc.

and there are many plans floating around the net for various kinds of tuners.

best regards..Mike
 

k9rzz

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I doubt that a tuner will increase the level of the received signal, but it may help in rejecting interference from stations on nearby frequencies.
It might help reduce bleed from local AM BCB stations, but the selectivity of antenna tuners is not that great for receiving. It will help you most the lower in freq. you tune to the point of being just about mandatory down on longwave (and there are no commercial tuners for LW, so you'd have to cobble something together yourself).

So, IMO. Yes, those little MFJs are worth the $ in the long run, but mostly on lower frequencies.
 

hertzian

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Dont forget to check the position of the antenna switch - hold ANT/set for 2 seconds to make sure you are using either the internal 10:1 balun for wires, or the 50 ohm connector for coax. You didn't mention how you are getting that wire down from the attic to the receiver...

If using a direct wire attachment to your 65 foot attic wire, make sure it is connected to jack #8, and not the ground (#7). I've gotten these backwards leaning over the top of the rig.

Manual tuners are a great thing to have - for long or even very short antennas. I currently use a simple 8-foot tall "L" vertical - indoors even - and tune it down to 2.5 mhz all the way up to 30 mhz with good results, although with such a short antenna, the settings are touchy. I'd LOVE to have 65 feet to play with.
 
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SCPD

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MFJ makes a SWL tuner got the MFJ959B years ago for the Icom R71A, worked fairly good on the long wire. They have a newer version now, some of the Ham tuners may work but they are mostly for transmit.


MFJ Enterprises Inc MFJ-959C.

David Kb7uns
RE: SWL Utility usage

YMMV, but I tried the 959C a couple of years ago and while it did "slightly" improve the signal in some cases (against a 300ft random wire) -- it ultimately wasn't worth it because by the time you can "tune" the signals -- they're gone.

You might see a case of improvement with a SW portable and a limited antenna system versus a desktop receiver plus decent antenna.

In the case of the R-75, if you had a limited antenna (and are using the Hi-Z antenna input) then you might see added benefit.

If you're listening to SW BCB stations then this could help in tuning some weaker stations to maximize antenna performance. This performance gain is likely to be very small in most situations.

A tuner can help with limited antenna systems but IMHO, it's generally not worth it.
 

Halfpint

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I've tried several "Antenna Tuners" AKA "Pre-Selectors" over the years with somewhat limited results. I eventually came upon, and have settled on, the TIMEWAVE ANC-4 device which actually probably does exactly what you are looking for. It isn't an "Antenna Tuner" / "Pe-selector" but instead uses a second antenna that it mixes with your primary antenna and allows one to `phase out' just about any, within reasonable limits, most of the annoying `noise' and competing signals in whatever bandspread you are listening to.

I do a fair amount of AM BCBD DXing along with some HF broadcasting DXing with my IC-R75s and since I got my ANC-4s I have managed to dig out a lot of the signals, that in the past I hadn't been able to, almost as clean and clear as if they were locals. Yes, there are still a fair number that I still find myself straining to hear but, my `go to' list of stations to listen to has easily gone up by at least a factor of 10 if not more.

I'll admit that at times one has to do some fairly serious `tweaking' and `twiddling' of both the receiver and the ANC-4 but, once one has everything fall into place the results can be fairly startling at times. 'Course there also be times when nothing seems to work and might lead to some fairly `crisp' `cursing', too.
 
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