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RF Limited CR-577 Mic Review

Robb

Honorary Member Silent Key
Dec 18, 2008
11,432
3,652
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Silicon Valley CA, Storm Lake IA
This is an EXCLUSIVE review on the internet of RF Limited's new CR-577 mic. Some of you may have heard me talking skip this week with it. It is one hot mic - especially for the price. Another World Wide Radio Forum first...

I been using this new mic from RF Limited for less than a week. I used it the other day to make a contact with Curacao Island off of the coast of Venezuela. I've talked locally with a lot of friends on the radio - both on AM and SSB. Everyone liked it; they all said that it was loud, clean, cutting, and had a wide frequency response for a handheld mic. There was an overwhelming, clear consensus that this mic is a winner. No one didn't like it; no one had a problem with my modulation from Milpitas CA to Ft. Lauderdale FL.

It looks like the Xtreme 2018 or the TurboEcho mic made by RF Limited. The cord is made of quality buna rubber. Not made of cheap vinyl - like a stock Cobra mic. The cable looks like the same cable used for the Heil hand-held mics and the Astatic D104's that are currently on the market. When the mic is keyed, there is a red LED on the front of the mic that comes on. It uses a single 9v battery that installs the same way as the other RF Limited mics. It's a little lighter and has a thinner mic case than the Astatic 575 that it is replacing.

Like the 2018 Xtreme mic, it has two large knobs on the back of the mic. This is strictly a non-echo mic; nor does it have talkback. One knob is for mic gain, the other for bass roll-off. The pot for the bass roll-off is 1 mega-ohm in resistance; this provides for a wide range of adjustment to your liking. In the "0" position of the bass roll-off control, the mic sounds thin but xtremely clear. Turning it to "10" gives it a thick but piercing full-body sound that will rattle your fillings. I liked it between 2 and 5; some thought it sounded a bit thick when set at 10. Even at 10, it did not lose the high end response - but it did gain more bass than I expected of any hand-held power mic I've heard.

Videogate of CR-577 mic...
Yes - that is my voice on the radio.
YamahaDude is making the videogate...

YouTube - CR577 microphone by RFUnlimited

In control

The usable gain setting on this mic can be set a little as "3" and as much as "9'. When set all of the way open, it gets some distortion. The mic amp is well balanced, by the time you set it at 10 - one knows that it is too high. Much like running a D104 all of the way open - it is just a bit too much. It sounds very good at 3 and is still being driven well, and at 9 it will modulate as loud as the Skythumper will. With the exception of having a fuller range; something that the Skythumper cannot do. I usually run it at 8 - for the best balance between clarity and overall loudness.

Build a better mouse trap...

The element is a ceramic unit, and the mic electronics was modeled after the Astatic 575. Which is no longer in production. In fact, if one goes looking to buy a used Astatic 575 on eBay or elsewhere - you will find them often selling more than the did when they were new. Surprising? One would think so. The Astatic 575 mic is hard to find and can cost as much as twice as their original cost. No need to concern yourself with that dilemma - this RF Limited mic has a suggested retail price ("MSRP") of $59.95 and should be on the shelves by the end of March. It will compete for a few dollars more than the D104 when it hits the shelves at your local CB shop or internet store. That is my guess - but I think it is a fair one.

An interesting observation

This mic cannot be held three feet away like a handheld D104 can. In fact at that distance, it almost cannot be heard. One needs to get up on this mic really close for it to modulate properly. If there is such a thing a a power mic mixed with a noise cancelling mic - this is it. I will pick up some background noise, but it would have to be fairly loud to be heard in the mic. I have found that putting this mic up to one's upper lip will yield the best sound and modulation. Setting the tone control to 3 and the mic gain to 7 with the mic on the upper lip - practically no background noise can be heard while maintaining maximum modulation.

Opportunity knocks...

The real story behind this mic is that RF Limited saw an opportunity to remake the xtremely popular but hard to find Astatic 575 mic. Bowing to the will of the people, RF Limited realized the popularity and scarcity of the Astatic 575 and took the initiative to copy it's design and properties to fill this market demand. The first prototype was constructed and then had to be vastly redesigned after RF leakage affected its function. The next prototype solveded this dilemma - and then it was off to the races. They had the second prototype mic floating between the US and China for several month in order to work out all of the bugs and come up with a mic that can squeeze out all of the frequency range that any CB/Export radio can transmit. I was sent the very same 2nd prototype mic for this review.

Conclusion...

I think RF Limited hit another one out of the park with this mic. For the price, it is easily better than the D104/M6 in that it is a little clearer/sharper. Completely shreds the RoadDevil mic - it's not even in the same league. I can see a lot of these being sold based entirely upon what your own ears will tell you. Of course - it will not sound good on every radio - that will depend on the state of the radio's tune and how high the modulation has been internally adjusted inside the radio. But on a stock export radio or CB, I think that it is going to be the most sought after mic on the mobile mic market in the near future.

AS far as weak points, it has a couple. One is - that the knobs can too easily be changed when bumped around in your vehicle. The other is that the flat metal screen can also be bent inwards; as it doesn't incorporate a screen-type mesh like the Astatic D104. I wouldn't let a heffer sit on this mic either - it might be crushed if too much pressure is applied. The bass response on full is a bit much for most radios to be able to use. But at least - it is there if you radio can do it. Run the bass roll-off below/around 3 for the best overall sound - IMO...

I give it five out of five stars...

I will be updating this review and have more info coming in the near future...

*This mic was given to the writer for the explicit purpose of review*
 

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MSRP ??

I heard you calling CQ on 27.555 Friday (I think), Was this the mic that was being used??
 
well i wonder if this mic will suffer the notorious broken key switch like all the extreme mics??same design so i see a broken key switch in its future.
other than that it sounds like a winner .
60.00 might be a stretch though.its all about money ,people will still buy a d104m6b for half as much if they dont make the price more compatible.
thats what i,m thinking.

ps-the switch itself doesnt break ,the plastic parts that operate the keyswitch do.

has this area been looked at?
 
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Good job on the new mic review, I was hoping you would have a 575 ready to compare but I like the sound of the rf limited cr-577. i will be waiting for them to hit the shelves. Thanks Buckshot
 
BTW - The videogate in the review - I had no idea that YamahaDude was doing one. I just thought he wanted to hear the mic. Afterwards, he told me that he videogated it. He thought it would be more spontaneous that way. He was right...
 
good review.@2:50 guy said turn down mic gain should have done that on radio
NOT on mic itself as it only changed a little .also was top gun on while on am
good sounding mic.nice addition to a 257.i may have to get one
 
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good review.@2:50 guy said turn down mic gain should have done that on radio
NOT on mic itself as it only changed a little .also was top gun on while on am

Yeah, the TopGun Modulator was on while on AM.
Also, the TopGun Compressor was on while on SSB.
Radio screams on AM.
SSB is my main mode - works fantastic,
Regardless of what certain people on this forum think, it just blows away most of the radios I talk to while DXing.
You and I know this...
 
no offense , but you sounded over modulated everytime you keyed up . the higher the mic gain the worse it was to my ears . i could understand what you were saying all the time , but you always had the gravel voice with both the D104 and the new mic .
could you possibly do a gate with the mic again with the radio dead keying %25 of what it will cleanly swing for those of us that run our radios and amps that way so we can have an idea of how it sounds ?
thanks .
 
I would have to agree that it is overmodulated. You could have turned it down to 1 or 2 and still been real loud. At 3 it was still too much. Even the guy taking the video was trying to say that nicely. The third party that came on briefly sounded good though.

What happened to 36-40 being reserved for sideband?

PR
 
That sounds terrible to me. BADLY overmodulated the whole time, regardless of setting. Extremely crunchy. Loud? Yes. Clear? NO!!! Not even close to clean or clear. Awful.
 
maybe 1 watt swinging to 60 or 80 watts had something to do with it ?????
 

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