eHam.net - Amateur Radio (Ham Radio) Community

Call Search
     

New to Ham Radio?
My Profile

Community
Articles
Forums
News
Reviews
Friends Remembered
Strays
Survey Question

Operating
Contesting
DX Cluster Spots
Propagation

Resources
Calendar
Classifieds
Ham Exams
Ham Links
List Archives
News Articles
Product Reviews
QSL Managers

Site Info
eHam Help (FAQ)
Support the site
The eHam Team
Advertising Info
Vision Statement
About eHam.net


Reviews Categories | Receivers: General Coverage | MFJ-8100 Help


Reviews Summary for MFJ-8100
MFJ-8100 Reviews: 19 Average rating: 3.4/5 MSRP: $89.00
Description: Genearal Coverage SW reciever
Product is in production.
More info: http://
Email Subscription
You are not subscribed to this review.

Subscribe!
My Subscriptions
Subscriptions Help

You can write your own review of the MFJ-8100.

Page 1 of 2 —>

KG4NEL Rating: 4/5 Mar 17, 2014 14:47 Send this review to a friend
Not a lot of money - a lot of fun  Time owned: 6 to 12 months
Whether you’re a complete stranger to the world of HF or have a pair of K3s on your desk, sometimes it's a nice break to go back to how things were done before SDRs, IF DSP or even a frequency readout more complicated than a piece of plastic and a potentiometer. The 8100 is hardly the last word in performance, but it does surprisingly well for what it is.

The real value is in building the kit – price-wise, you can buy a modern Grundig or Sangean portable for less, but being able to assemble something that picks up voices from around the world (well, at least until the demise of international SW broadcasting…) is a thrill that hasn’t gotten old for me after a dozen years in the hobby.
 
BILZIN Rating: 5/5 Nov 7, 2013 14:13 Send this review to a friend
Potential DXer   Time owned: 0 to 3 months
Got one of these kits cheap on Fleabay for No1 grandson.WE built it in a very short time, and it fired up perfectly from the start. Some clandestine tuning on my part soon had it pulling in stations that my Yaesus had difficulty tuning, and the look on his face when he first heard it receiving is well worth the price and effort WE put in.
The X box has been relegated to the spare room for the time being, and I think WE might just have another DXer in the making here....hope so !
 
KO0KY Rating: 5/5 Aug 30, 2011 22:03 Send this review to a friend
More than I expected  Time owned: 6 to 12 months
I gave this rig a 5 because of the performance/price ratio, for the money it's hard to get a better rig that is so much fun to put together and use. It really does have a nostalgic feel to it that my higher performance radios just cannot have. Sure, my Grundig 750 is a lot better, but it costs $250. And you can't get it in a kit.

It is quite satisfying to run around the bands, reliving my early SWL days in the 60's, when I used whatever I could get my hands on. I would have killed for a rig like this. Now that I have much better radios, I use this one more than the others because of that remembrance. I can't quite put it into words, but you know it when you see it.

It's also great for travel. When I take my G4000 on a trip, I have to pack it really well so that the TSA folks don't smash it, not to mention it might just come up missing. This one is so tough I'm not worried at all, and it's so ugly I can count on it not being stolen.

Anyway, I highly recommend it.

John
 
NO4L Rating: 5/5 Apr 27, 2011 00:37 Send this review to a friend
Latenight Fun!  Time owned: more than 12 months
What positive can I say that hasn't been said already? I enjoy playing with this receiver late at night. It's hooked to a Radioshack amplified speaker, the sound is really quite decent for what it is. I've tuned into all sorts of broadcasts with 100' of wire wrapped 5' bamboo pole with a capacitance hat made out of aluminum on the top -- ugly but it works and doesn't take up much room. Even a 10' piece of wire will offer up some stations.

Received it as a gift for Christmas nearly a year-and-a-half ago, and it continues to keep me amused.

The wired version costs less than most 2M HT's, and offers up a lot of fun in a small package. Just get one!
 
AI4HO Rating: 5/5 Aug 4, 2010 10:48 Send this review to a friend
Neat little receiver!  Time owned: 3 to 6 months
I picked up one of these from a guy in Ca. for a couple a bucks, $35 or $40 by the time shipping to Fl was established. This is one neat little receiver,the one mod the guy I bought it from was too by pass the battery system altogether, and just have it powered by 110v. Not a problem as this was going to be in my shack and not go any where. Once I found a suitable wall wort in my junk drawer, I had some speaker wire that I attached to the rear of the radio, its performance at first was lousy. What I hadn't realized was that the wire was intertwined with a bunch of other stuff and was lying on the ground.

I then cobbled together an off center fed antenna using the same speaker wire. I attached one end to my tower and the other end to a tree in mt front yard. I guess the antenna was 20-25' in the air, what a difference, I was getting stations from all over, Cuba, BBC broadcasts, all over the US, I was in heaven. One thing I had to get used to was the tuning, the MFJ-8100 tuning control is quite smooth, and using the regen in conjunction with the tuning knob was at first a little tricky, but with a little practice and a lot of patience, I was able to tune pretty much anything.

Well, tragedy atruck, we bought a pop up camper and to work on it we moved it into the front yard. In cranking the camper up I forgot about the wire antenna for my regen receiver, next thing I knew there was this wire hanging down in front of me and I'm thinking what the hell?? At first I didn't realize what it was, then it dawned on me,what it was. OK, I get to it and get it fixed in a couple of days. Not so, it got really, really hot hot here in our part of Fl., work has pretty much ceased on the camper at least for now, got most of it done, just a few other minor things to do. I have the pieces of wire and its all together again, I just have to get it up in the air. I moved the 8100 into the back room with my other radio collection, and when I went to plug the wall wort in the radio wouldn't turn on. My el cheapo wall wort, on the one side the spade plug had pushed into the assembly, n problem I can fix this.......not yet any way, the assembly is sealed, so I'm either going to have to disassemble the unit all together or find a new one. Think I'll just find a different one in my junk drawer. I do like this receiver, it may not be a high end Icom, Kenwood,or Yaesu, but for what it is its a neat little receiver that will be part of my shack for a while yet.



73 de Mark
W3LZK
 
KO0KY Rating: 3/5 Sep 25, 2009 09:33 Send this review to a friend
Worth it at an eBay price  Time owned: 0 to 3 months
I purchased one of these recently from a chap on eBay for $30. He had added one mod, a spring clip 9V battery holder on the back. I highly recommend this addition to the radio as it saves so much time changing batteries.

I have tuned up SW broadcasters all over HF with this radio quite easily. You really have to get the 'feel' of the regeneration control, however, which is quite tricky. Once you conquer this you've got it made.

I've also picked up quite a few hams on AM (75m nets), SSB & CW, and they are quite understandable. I am impressed with how sensitive this rig is and how good the audio is. I'm going to add an amplified speaker and use this in my shack as an SWL receiver while I build kits and otherwise piddle around.

One little feature that I really like is the double headphone jacks. My XYLis studying for her Tech license, and I can show her directly about shortwave this way.

Overall, for the money, it is a good deal...conditionally at eBay prices. I can't imagine paying full price for this, especially $109 for the wired version. I will say that I have had a lot of fun with this rig and plan on having a lot more. That's a pretty good bottom line.

KO0KY
 
AA1UY Rating: 4/5 May 28, 2009 18:54 Send this review to a friend
Still using it years later  Time owned: more than 12 months
I assembled one of these in kit form a few years back and still use it from time to time. You really need to use an outdoor antenna and it works better grounded than not.

It is, as someone said, a 3 (three) transistor radio based on an almost 100 year old design but built using more modern components. It's just about one step up technology-wise from the crystal set (cardboard tube, a rock and some wire). As such, I think it performs very well for what it is.

It's not an $800 communications receiver, nor a modern portable and it's not even a superhet design. It's a regen and as such, displays traits common to regenerative receivers in general (surprise, surprise).

My MFJ 8100 kit went together without a hitch and works as advertised; in fact, it can be quite sensitive if you patiently adjust it correctly.

Those of us who enjoy back to basics radio and QRP can find regens quite addictive (if frustrating at times).
 
W0IW Rating: 0/5 May 27, 2009 11:37 Send this review to a friend
RUNN... AWAY !!!!  Time owned: more than 12 months
I bought this second hand from Gigaparts... Cost $20.00 used.. I thought wow what a great deal for a cool kit that would receive ham/shortwave..

The radio is totally unstable... the tuning is so touchy you wont be able to seriously use it !!!

The sensitivity is pretty mediocre at it's best !!

OTHER THAN THAT GLOWING REVIEW ENJOY !!!
 
N3NXD Rating: 2/5 Apr 10, 2009 17:14 Send this review to a friend
Needs surgical intervention  Time owned: more than 12 months
I bought mine way back in 1998. As a kit experience, no problems. Had for years, a problem with hand capacitance, and signals easily overloaded. I first tackled the overload with installation of a 10 pot in series with antenna internal wire. Later, tackled hand capacitance issue with removal of all surface of board wires, and internal antenna wires. Replaced with sections of junkbox sheilded phono wires hooked up in place of original wires. Grounded braid of each wire to enclosure. No more hand capacitance! Better signal strength, much reduced interference too.
 
W3FIS Rating: 5/5 May 1, 2008 07:59 Send this review to a friend
Lots of fun  Time owned: 0 to 3 months
I first ran a parts inventory. All of them were there, though the list did not call out the IC socket for the audio amplifier. The regeneration and audio pots were not marked for values, so I need to break out the ohm meter to check them. The inductors for the tuning system are just like in the Ten-tec 1253, except for the single toroid to be wound by me.

There is lots of space on back panel for a UHF connector, battery jack, and toggle for the power. I want to be able to use an external power supply, and feed the receiver with a shielded coax, if I desire. I have a lot of EMI in the shack, so my antenna feed is with coax.

I will need to decide about the RF gain control, as it may be a little tight for a 10K pot I got at Radio Shack without drilling another hole. A careful reading of the instruction manual suggests that I won't have to adjust it often. This is the case on my Ten-tec 1253, where I only have to cut the RF gain back when I have one of those megawatt SW broadcast stations in the evening.

I can decided when I get the board populated and fit it to the case, and see what sort of space I have. At that point, I'll drill the hole for the power jack and power toggle (would have used "steering" diodes, but no good place to hang them). I couldn't find one of the power jacks with the built in transfer switch, or would have used that. I can just use my 5/8" Greenlee punch to punch out a hole for the UHF connector. I will leave their binding post in place, so I can easily switch from coax feed to wire, as I wish.

General small parts insertion and soldering went well. A 30 watt iron is clearly necessary to get enough heat. This board doesn't use the plated through holes that I am used to, so the soldering technique is a trifle different. As usual, examine each soldered joint as you make it, and then clip the excess wire off. Some of the pads are pretty close, and I had to fix one solder "bridge." The discussion on mounting the LED pilot light is simply wrong. You need it off the board about 1/4", and then bend 90 degrees to fit the hole in the front panel.

Larger parts need a little coaxing, etc., to get them in place, especially the main tuning capacitor. The single toroid is easy to do, especially as hookup wire is used to wind it. Mechanical assembly issues next, and I need to decide about the RF gain control. I think I'll go with the standard setup for the time being, so since I deferred soldering it in, I'll do that now.

Time to lay out and drill the holes for the power jack, power switch, and UHF chassis connector. I'm going to use one of the single nut attachment types, which has a locking washer under it. Neater in appearance, and no holes to get lined up.

Attaching the dial pointer is a PITA. Very tight fit. Reamed it open a tad with an Exacto knife, then secured it with a drop of contact cement. I also used some hot glue to secure the toroid to give it more mechanical stability. I also used more zip ties to secure the battery cable, etc. I still need to calibrate the receiver, but I'll do that some evening when I can hear WWV.

The tuning is quite smooth. The vernier tuning is just right for tuning in a regenerative receiver. Regeneration goes in and out smoothly. The usual stuff of tweaking up the regeneration point on the top band.

Right now, I'm feeding the audio through a amplifier/speaker, but headphones are quite satisfactory. I have not tried an external power supply yet, though of course, I do have the jack and switch in place. The current antenna is a 1/4 wave end fed for 40 meters that I use for my QRP transceiver.
 
Page 1 of 2 —>


If you have any questions, problems, or suggestions about Reviews, please email your Reviews Manager.