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Reviews For: MFJ-8100

Category: Receivers: General Coverage

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Review Summary For : MFJ-8100
Reviews: 25MSRP: 89.00
Description:
Genearal Coverage SW reciever
Product is in production
More Info: http://
# last 180 days Avg. Rating last 180 days Total reviews Avg. overall rating
00253.7
KC2QCZ Rating: 2006-09-28
Remember what it is! Time Owned: 0 to 3 months.
This radio is crud.
But yet I love this radio. Why? It's the first radio kit I every built, the first time I ever soldered, and it worked! The MFJ-8100 is very easy to put together for someone who has some theoretical knowledge of electronics, but no practial experience. The manual is comprehensive and very well written, but some of the components were of slightly different types than the book. Many of the capacitors were of different tolerance than the ones spec'd out in the parts list. For example, the manual says that there were 5 0.1uF capacitors labeled 104Z, but they included 4 0.1uF with 104M and 1 with 104Z. If one didn't understand the markings, one might be confused. Mounting the board was a pain, until I noticed a little plastic mold nubby on the case of the bandswitch. I nipped it off and then everything went together nicely.
Receive performance with a random wire about 20 feet long, is, frankly, abysmal. I did pick up a number of SSB signals, but there's no real way to tell what frequency, as calibrating the dial (actually described in the manual!) was beyond my patience/skill. My $20 pocket shortwave radio works better than this over a larger range with much higher sensitivity. So why did I give it a 4? Because one should keep in mind what this is. This is an introductory kit for people with little/no experience to build, and there's a great joy in finishing the radio and then turning it on for the first time, and actually hearing a signal, badly distorted and noisy, but still a signal! From a device built with your own hands! And that's worth the price of admission.
I should point out that the case provided is very nice, and once the you close up the case, it looks very professional and commercial.
K3MD Rating: 2005-12-25
Fun Time Owned: 0 to 3 months.
I bought this unit pre-assembled. It out-performs my other two regenerative receivers by a wide margin. It is a little tricky to tune in CW, as expected. It would make a good QRP receiver for 80 or 40 meters, as long as the spotting signal were attenuated. Nicely written manual. It does fine on the SWL bands, no problem. There is a little bleed-through from AM brodcast, they have filters for this, not unexpected. Regeneration is stable and smooth. An RF gain control (on the back panel) is a nice touch.
W7AAR Rating: 2005-04-18
Don't waste the $ Time Owned: 0 to 3 months.
Built this as a warm up for my KX1 and to give my grandson the experience as well. Rather simple kit but several parts(pots) were mislabled/misnumbered/not numbered. Dial pointer is impossible to put on without breaking it. Tuning accuracy/dial is one notch above a crystal set. Did work somewhat after I hooked it to my Windom but overall seemed very marginal. I have an MFJ keyer that works just fine but this will be my last MFJ purchase.
KO4MH Rating: 2004-02-13
Works well for me Time Owned: more than 12 months.
I built this receiver kit several years ago and it works well for me. Frankly it is amazing what sensitivity these regens can give - although you must adjust a little as you change frequency. I use a 20 foot wire for my antenna. Works well demodulating CW and SSB, although, as you should expect, the selectivity is nowhere near a good superhet.
As another reviewer pointed out, stability is a little problem (mine shifts frequency as you move the headphone cord around, but its not too bad). In summary, I like it. I use it periodically and enjoy playing with this old, but neat kind of receiver architecture.
N8BEG Rating: 2003-12-12
terrible performance.... Time Owned: 0 to 3 months.
To qualify this viewpoint, I have built many recievers/transmitters in my life. Many, I have designed. And, I have built regens before. So I knew what to expect. This radio is a regenerative reciever, but, if you read the MFJ literature on this radio, they talk about it being "an improved design" over the popular regen designs, etc...etc........they sell it beyond it's capabilty. I wanted a small radio; battery powered that would recieve CW/AM/SSB that I could take to Hunting camp; on the Road....etc..you get the idea. I was very dissapointed. It isextremely unstable. You can't tune or find anything...the regen sensivity changed radically with every turn of the dial ( this is normal with the REGEN approach but, there are ways to minimize this by limiting bandspread, etc) . The sensitivity was irregular. BOTTOM LINE: .....this thing sucks. This radio is not worth $20........