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MFJ Enterprises MFJ-557 Morse Code Practice Oscillator

4.8928 product ratings

GigaParts (25878)
99.1% positive feedback

Price:

$85.45

Free shipping

Estimated delivery Tue, May 14 - Thu, May 16

Returns:

30 days returns. Seller pays for return shipping.

Condition:

New

The MFJ-557 Deluxe Morse Code Practice Oscillator features a Morse Code straight key on a non-skid heavy steel base -- it stays put on table and doesnt move around while youre sending! The MFJ-557 Deluxe Morse Code Practice Oscillator runs on a 9 volt battery (not included) or 110 VAC.

About this product

Product Information

The MFJ-557 is a Deluxe Morse Code Practice Oscillator straight key model developed by the MFJ Enterprises brand. It has a contact pushed to create and send the practice message, and it has dimensions of 3.75-inches by 2.75-inches, which makes it compact and easy to carry. The radio and communication device is handy in learning the coded language which is useful for sending short messages.

Product Identifiers

Brand
MFJ
GTIN
0702646177954
UPC
0702646177954
eBay Product ID (ePID)
1737650127

Product Key Features

Year Manufactured
Easy to use
Compatible Brand
For Ten-Tec, For Yaesu, For Icom, For Heathkit, For RadioShack, Universal, For Kenwood, For Realistic, For Elecraft, For Drake, For Collins, For Hallicrafters, For Wouxun, For Ranger, For Galaxy
Features
Built-In Headphone Jack, Volume controls
Compatible Model
eBay US

Dimensions

Height
2.25in
Width
3.75in
Item Weight
1.25 lbs

All listings for this product

item 1 MFJ-557 Deluxe Morse Code Practice Oscillator Straight Key w/ Volume Control
$55.00
Free shipping
item 2 MFJ Enterprises MFJ-557 Morse Code Practice Oscillator
$55.00
Free shipping
item 3 MFJ-557 Deluxe Morse Code Practice Oscillator Straight Key w/ Volume Control
$85.45
Free shipping
item 4 MFJ-557 Deluxe Morse Code Practice Oscillator Straight Key w/ Volume Control
$79.99
+$12.95 shipping
item 5 MFJ Enterprises Original MFJ-557 Deluxe Morse Code Practice Oscillator Straig...
$117.01
Free shipping

See all 5

4.9

4.9 out of 5 stars based on 28 product ratings

28 product ratings

26 users rated this 5 out of 5 stars
1 users rated this 4 out of 5 stars
1 users rated this 3 out of 5 stars
0 users rated this 2 out of 5 stars
0 users rated this 1 out of 5 stars

Would recommend

Good value

Good quality

Most relevant reviews

See all 24 reviews

5 out of 5 stars
by murpee0Nov 05, 2019
Top favorable review
Well designed and very rugged.
This is a very rugged unit. I do like the rubber skid pads that help to grip on flat surfaces. The unit assembles easily. It is great for ''gadget'' type hobbyists, yet I did MC in the military, and this is the genuine article.
Product Reviews Images
Verified purchase: Yes | Condition: New
3 out of 5 stars
by 94bondJan 13, 2017
Top critical review
fine key, ugly oscillator
I'm pleased with the key, but not with the sound of the oscillator. Each beep descends rapidly in pitch, with the result that even perfectly keyed morse code sounds a little drunk. The tone is also raspy and harsh (triangle wave). I checked some YouTube videos, and it seems these traits are typical of this model, although not all descend in pitch as much as mine does. My oscillator is so repulsive to my ear that I ended up buying a serial to usb conversion cable so I could use software on my computer to generate the sound. If I had known the oscillator was going to be like this then I probably would have purchased a higher quality key without an oscillator.
Verified purchase: Yes | Condition: New
5 out of 5 stars
by niog_58Feb 05, 2023
Nice little self contained morse key.
Morse key with adjustable gap and tension. Volume and tone button. Takes a 9v battery. Reasonable sturdiness and weight. Decent quality for price and an all in unit for anyone who just wants to either learn morse or practice morse.
Verified purchase: Yes | Condition: Pre-owned
5 out of 5 stars
by jihus-36Oct 03, 2018
GREAT Product!!!!!
This device has really helped me to send Morse Code much better. After listening to my coding, I have recognized several issues that I need to address to send more consistent cod. Thank you for a wondedrful product. -Dave H,
Verified purchase: Yes | Condition: New
5 out of 5 stars
by lada1467May 05, 2021
Works great
Works great, heavy enough to not move around, rubber pads prevent scratching surfaces. I see no need for a separate power supply, the battery is lasting a long time.
Verified purchase: Yes | Condition: New

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Picture 1 of 1

MFJ Enterprises MFJ-557 Morse Code Practice Oscillator

About this product

Product Information

Product Identifiers

Product Key Features

Dimensions

All listings for this product

item 1 MFJ-557 Deluxe Morse Code Practice Oscillator Straight Key w/ Volume Control

item 2 MFJ Enterprises MFJ-557 Morse Code Practice Oscillator

item 3 MFJ-557 Deluxe Morse Code Practice Oscillator Straight Key w/ Volume Control

item 4 MFJ-557 Deluxe Morse Code Practice Oscillator Straight Key w/ Volume Control

item 5 MFJ Enterprises Original MFJ-557 Deluxe Morse Code Practice Oscillator Straig...

Ratings and Reviews

Most relevant reviews

Well designed and very rugged.

Product Reviews Images

fine key, ugly oscillator

Nice little self contained morse key.

GREAT Product!!!!!

Works great

Best Selling in Code Keyers & Keys

Military Harris RF-3016-03 Telegraph Knee clip Morse Code CW Radio Key J-37

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