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MFJ Enterprises MFJ-557 Morse Code Practice Oscillator

cleaningoutthehouse2day
(11986)
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US $55.95
ApproximatelyC $76.61
or Best Offer
Condition:
Used
Shipping:
Located in: Dacula, Georgia, United States
Delivery:
Varies
Returns:
No returns accepted.
Payments:
     Diners Club

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eBay item number:177000889715
Last updated on Apr 21, 2025 08:21:01 EDTView all revisionsView all revisions

Item specifics

Condition
Used: An item that has been used previously. The item may have some signs of cosmetic wear, but is ...
Type
Oscillator
UPC
0702646177954

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

Dimensions

Height
2.25in
Width
3.75in
Item Weight
1.25 lbs

Item description from the seller

About this seller

cleaningoutthehouse2day

99.7% positive feedback•32K items sold

Joined May 2011
Usually responds within 24 hours
Welcome to my eBay Store. Please add me to your list of favorite sellers and visit often. Thank you for your business.I mostly sell childrens clothing & toys and household items
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Detailed seller ratings

Average for the last 12 months
Accurate description
4.9
Reasonable shipping cost
4.8
Shipping speed
5.0
Communication
5.0

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Seller feedback (12,801)

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  • 8***7 (137)- Feedback left by buyer.
    Past month
    Verified purchase
    The package was delivered very quickly, within 3 calendar days of the order date and on a national holiday weekend no less! The power supply was quadruple-wrapped in bubble-wrap and nested in a double-thickness cardboard box. It arrived in the same excellent to like-new condition it was sent. The DM-330MV is unusual in its price class in that it conservatively supports 30A with 32A peak. Most similar quality units support 20A or less. I would positively buy from this seller again.
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  • x***a (38)- Feedback left by buyer.
    Past 6 months
    Verified purchase
    Well packaged, no damage with the packaging at all. I had great communication with the seller about shipping. This was a very good transaction. The item was exactly as described. I Would do business with you again. Thank you.
    Coats & Clark’s Book No. 207 Shawls and Ponchos Crochet Knit Hairpin Lace (#186456875084)
  • l***n (586)- Feedback left by buyer.
    Past month
    Verified purchase
    The graphic novel was packaged well in bend-resistant packaging. However, the novel came with a small crease on the top of a good amount of the pages. These pages also had a tiny tear where the creases occurred. I believe that this damage came from something that was jabbed through the top, as I saw a gash in all of the layers of the packaging that lined up with the creased section. I believe that it is likely that this damage was caused during shipping as it did get lost for a period of time.
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Product ratings and reviews

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4.9
26 product ratings
  • 24 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 22 reviews
  • by murpee0
    Nov 05, 2019Top favourable 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.

    Verified purchase: YesCondition: NewSold by: C87jFBdoTXq@Deleted

  • by 94bond
    Jan 13, 2017Top 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: YesCondition: NewSold by: gigaparts

  • by niog_58
    Feb 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: YesCondition: Pre-OwnedSold by: spray281

  • by jihus-36
    Oct 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: YesCondition: NewSold by: gigaparts

  • by lada1467
    May 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: YesCondition: NewSold by: gigaparts

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