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Reviews For: MFJ-640 2 Radio Selector/Mixer

Category: Audio Accessories for Transmitter & Receiver

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Review Summary For : MFJ-640 2 Radio Selector/Mixer
Reviews: 3MSRP: 49.95
2-Radio Headphone Selector/Mixer

MFJ-640 combines or selects audio from two different receivers -- Great for operating "split" for HF contests and DXing, or cross-band for VHF/UHF satellite.

Just connect the audio output of two receivers to the two 3.5mm audio connectors
on back of the unit. Then plug in your stereo headphones and you are ready to go.

MFJ-640 provides both 1/4” and 3.5mm stereo headphone jacks -- no need for adapters!

From the front panel you can select the audio output desired - Mix, Radio 1,
Stereo, or Radio 2. In the Mix mode both radios are combined in both the left and right earphones, and the audio mixing levels between the two radios are controllable. In the Stereo mode, Radio 1 is heard in the left ear and Radio 2 is heard in the right ear.

Compact 4 3/4W x 2 1/8H x 5D inches.
Product is in production
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# last 180 days Avg. Rating last 180 days Total reviews Avg. overall rating
K7JQ Rating: 2019-08-20
Does what it's supposed to Time Owned: 0 to 3 months.
Picked this up from the classifieds when I purchased my second IC-7300. Very convenient for various mixing of headphone audio between the two radios. Small, passive, and works as described. Neat accessory for the shack.

73, Bob K7JQ
N0TLD Rating: 2018-01-18
Great accessory Time Owned: 0 to 3 months.
I've just picked up one of these little guys from a local ham swap about a month ago, and have been using it in conjunction with a diversity reception set up. It works beautifully.

As most other accessories in the shack tend to need power, having this one passive is really nice. It's one less source of noise in the audio chain.

There are different ways to configure and mix and match and balance audio signals, and this thing does it all like a champ.

One of the best assembled, sturdily built MFJ products I've ever seen.

You don't realize how much you might need it until you *have* it, and then you'll wonder how you did without it for so long.
NI0C Rating: 2010-12-26
Simple, handy accessory Time Owned: 6 to 12 months.
I use this unit to select or mix the receive audio from my K2 and K3 transceivers. By also using an antenna splitter with the receive antenna inputs of the two radios, I have dual-receive capability, with the audio either mixed or in stereo. The unit uses passive circuitry and requires no power.