Manager


Manager - NA4M
Manager Notes

Reviews For: MFJ 94-Series

Category: QRP Radios (5 watts or less)

eMail Subscription

Registered users are allowed to subscribe to specific review topics and receive eMail notifications when new reviews are posted.
Review Summary For : MFJ 94-Series
Reviews: 75MSRP: 239.95
Description:
SSB Travel Radio (CW optional)
Product is in production
More Info: http://www.mfjenterprises.com/index.htm
# last 180 days Avg. Rating last 180 days Total reviews Avg. overall rating
00754.4
VE3GZB Rating: 2012-12-09
Waste of money Time Owned: more than 12 months.
I've owned my MFJ9420 over a year now and even on a dipole 35 feet up in the air, where my TS2000 or TS820 on 10 watts can QSO over to France and Italy on the same antenna, in all of this time I've only ever had one successful QSO with the 9420 and it was only on the North American contintent.

It does receive ok, and according to the SWR meter in my tuner it is putting something out and the SWR is unity.

I would not recommend this radio at all, unless you have cash you can afford to waste.

73s VE3GZB

----------------------
Earlier 2-star review posted by VE3GZB on 2012-12-07

I finally managed to QSO with my MFJ9420. I did run into a problem however.

Since I use it with lightweight rechargable Lithium batteries, their output voltage will fall as they discharge.

What I've found is that a given mic gain setting that works at a lower DC input voltage will cause trouble if a freshly charged battery pack is used with the radio, and it is a pain to have to fiddle with it to get it to behave.

My solution was to install a standard TO-220 Non-plastic case 7812 voltage regulator within the case of the '9420.

It's not hard. Here's how you do it.

First prepare the 7812 with suitable bypass capacitors on the input and output side. For the input side I used a 220uF in parallel with a 0.1uF cap.

On the output side I used 10uF in parallel with a 0.1uF cap.

Now on the circuit board? From the DC connector look for a zig-zag skinny trace. This is a fusible link. Cut it with a knife somewhere in the middle. That breaks the unregulated DC input.

Loosen and remove one screw and nut from the RF output connector and use that as a mounting point for your 7812. By grounding the tab of the 7812 to this point, you complete your grounding.

At this point, tie your regulator input to the DC input connector V+ pin and your regulator output to the other side of the fusible link which you previously cut.

Now your radio's mic gain and performance will be consistent despite variations in your rechargeable battery voltage.

73s VE3GZB
----------------------
Earlier 1-star review posted by VE3GZB on 2012-10-30

I bought a 9420 last year in hopes of taking it into the forest and working some clandestine DX QRP.

But first I connected it up to my 20/17m homebase, with a helical dipole, balanced feedline and balanced tuner which I've successfully worked multiple countries.

I could hear plenty of activity on 20m. I know I was tuned up for minimum SWR. I know the transceiver was drawing current as I spoke into the mic.

But even at maximum output I was not heard.

I disconnected the radio and put my TS-2000 back, fired it up on 5 watts and managed QSOs.

So while the MFJ-9420 seems like a novel and cute idea, it would help a lot if it would actually work. To this day it just sits under my bench, gathering dust. It seems to be well qualified to do just that.

73s,
VE3GZB
VE2BXJ Rating: 2012-10-09
SSB fine, CW board awful Time Owned: more than 12 months.
It's fine for SSB and I have made it work for digital modes using a mod to make SSB work on the lower portion of the band (needs the CW add-on board).

But for CW, don't even bother. The side-tone alone is enough to make you go nuts. It's more like a squeal than a tone. Don't buy this radio if you're planning on using it for CW. I sold my MFJ-9420 and used the money to get a FB1B.
EA1HFI Rating: 2012-09-24
Un QRP Excelente!! Time Owned: more than 12 months.
El 9420 se describe como un "equipo portátil" pero es sobre todo un transceptor de SSB, aunque se le puede añadir CW con un modulo plug and play. Con esta pequeña belleza y sus 10 vatios PEP es fácil de lograr muchos contactos agradables, ya sea desde base, móvil o lugar de vacaciones. Funciona con un voltaje nominal de 13.8, y un consumo de 2 amperios en transmisión, por lo que una pequeña fuente de alimentación o unas baterías de NiCad pueden ser utilizadas.
El micrófono es de la impedancia habitual de 600 ohmios y del tipo dinámico, el único requisito extra para estar en el aire que es algún tipo de antena de 20 metros.
He utilizado este equipo desde la estación de casa con mi dipolo y he tenido varios contactos DX, entre ellos EEUU, Canada, Japón o Kasajistan, también he tenido muchos contactos por Europa.
Al ser una plataforma compacta es ideal para el uso portable ya que con solo una pequeña batería o fuente de alimentación, un balun 9:1 y 17 metros de cable puedo salir al aire desde un prado, montaña o el balcón de un hotel .Con esta configuración he realizado muchos QSOs entre ellos Escandinavia, Alemania, Irlanda, etc.
Con una antena telescópica de 2 metros de largo reciclada de un Walky y un balun de 10:1 LMZ-50, también he realizado varios contactos por Europa!
La calidad de audio en transmisión es excelente, debido sin duda a el procesador incorporado, he tenido excelentes informes de audio no solicitados.
Hay pocos controles en el panel frontal, el VFO, volumen , conector de micrófono, un medidor analógico, un par de LEDs, un interruptor de encendido y otro botón para "sintonizar" que lo que hace es emitir una portadora de baja potencia para poder ajustar con el acoplador externo las estacionarias. El receptor de audio y la selectividad es muy aceptable.
En la parte posterior, sólo se encuentra la entrada de CC y el conector de antena, sin embargo, hay agujeros para la placa opcional de CW (que yo tengo instalada) también hay un pequeño orificio por donde se accede al potenciometro interno de ganancia de micrófono… Y ya está! No hay DSP ni memorias, ni frecuencimetro digital, ni nada mas! , usted sólo tiene que enchufar el equipo y operar, es tan simple y sencillo como eso y funciona muy bien. Hay un poco de deriva al encender el equipo en frío, pero después de un par de minutos la frecuencia es de roca sólida.
El PA es un robusto MRF477, pero hay que tener cuidado, por supuesto, y darle una carga de 50 ohmios.

Modificaciones
Ninguna modificación es realmente necesaria, pero yo le he realizado (por ahora) un par, he puesto una salida de auriculares en la parte frontal del equipo y es muy útil para lugares ruidosos o escuchar mas "fino". La otra modificación fue agregarle un portafusiles exterior en la parte trasera.Esta modificación fue un poco forzada ya que en un descuido se invirtieron los cables de alimentación y le dije adiós al fusible interno que viene en la placa PCB (realmente no es muy buen sistema). Afortunadamente hay un diodo montado en paralelo, seguro pensaron en mi!, así que no hubo ningún daño en el equipo! ¿Crees que nunca lo harás verdad?, yo pensaba lo mismo !…
Estoy dispuesto a recomendar el MFJ 9420 como un eficiente y pequeño equipo SSB para la banda de 20 Mts., aunque el precio es un poco alto en Europa (alrededor de 300 euros). El principal proveedor en Europa se encuentra en el Reino Unido y se llama Waters and Stanton (tel: 01 702 205 843), con la que no tengo ninguna relación comercial, ni tampoco con MFJ.

Especificaciones técnicas:
•Cobertura de 14,150 a 14,350 MHz transmisor-receptor superheterodino de simple conversión
•OFV: 4,150 a 4,350 MHz
•SI: 10 MHz (acceso por escalera de filtro utilizado)
•SI selectividad 6 dB a 2,5 KHz
•AGC - derivados de audio
•Audio: más de 1 vatio en el altavoz incorporado de 8 ohmios
•TX picos de 2 amperios (13.8 voltios)
•Consumo en RX, 50 a 100 mA
•Salida de 10 vatios PEP
•CA 03:01 tolerancia
•TX de audio: la compresión de RF del procesador, 600 ohmios micrófono
•Medidor analógico, unidades S en modo receptor, y potencia / ALC en transmisión
•CW disponible en forma opcional en formato plug and play
ON6KE Rating: 2012-09-08
Can't believe this. Time Owned: 0 to 3 months.
I bought myself a 9420 (the new version with fine tuning) today in The Netherlands, came home in Belgium and started playing in the late afternoon right away with this little radio.
Today is September 8th so it's the WAE SSB contest, OK they need the points.

I worked Asiatic Russia several times in the afternoon, North- and South America as of 20:00Z and Africa with an EA8 all of it with 10 Watts PEP, 5 continents.
Tomorrow I'll get up and try working Oceania for continent #6, wouldn't that be something!!
Before I forget, my antenna is a low 20m Windom,

This little gem is full of life, it's pretty stable if you give it a few minutes after switch on and it's PUNCHY, I've heard it on my TS590S with a dummy load as antenna.

It's going to be fun when I take the rig with me on vacation to Malta mid-September!!



WB6V Rating: 2012-07-15
works good Time Owned: 0 to 3 months.
Ordered a mfj-9420 & 971 tuner directly from MFJ in April. After adjusting the mike it worked perfectly right out of the box without the alignment problems noted in earlier reviews. Using a Par 20m endfed antenna in a vertical position from a tree limb it receives well. I called cq when I first turned it on and made qso's with Colorado, NM & SoCal from my NorCal QTH. Worked the IARU contest this weekend and made 11 QSO's in 2hrs: Tx,Mt,SC,Mn,Va, 2 in MD & La. Also had 3 dx Qso's: Chile, Argentina & Japan. All from my Northern California QTH. Had several that I couldn't complete but at least they heard enough to answer my call initially.
I realize that the antenna is at least half of the success but all in all I'm pleased with the rig. It's a lot of fun to operate.
When I placed my order I emphasized that I wanted the rig to be aligned and operate as expected. Perhaps my comments helped ensure that the quality control had been done. In a follow up call to MFJ tech support on another unrelated item I mentioned my pleasure with the 9420 and they related that they had been working on the production line to improve the quality issues that plagued some of the earlier units.
Great unit which I would again.
GM3HNN Rating: 2012-04-26
Long Live QRP! Time Owned: more than 12 months.
At first glance, it looks like a 1970's old CB!!, but on operation, superb!! I only work QRP, and have worked the world with these things..I use the CW version + the 9420, always good reports, and yes, the build could be a bit tighter, but for the money and the fun, its just superb! Great fun outdoors, through a wire antenna over a tree, and away you go!, I also use the 971 ATU, just to get it perfect, recently worked far side of Russia from the beach at Brighton, showing around 5watts! so cant be bad, every ham should have one of these, well done MFJ
W5LV Rating: 2012-02-02
GREAT QRP RIG Time Owned: 0 to 3 months.
I ordered a MFJ-9475 from HRO on 11-3-2011. This radio was back ordered and I finally received it on 1-23-2012. When I hooked it up and turned it on the receiver would not copy a LSB signal. I could not get the radio to receive. The transmitter was putting out 12 watts. I called MFJ and they told me to bring the rig to Starkville and they would fix or replace it. They checked it out and replaced the radio. Really a nice rig. Great audio. No drift after warm up. I use it on a 75 meter net. I bought a 4 amp power supply to power the rig. Also use a MFJ tuner and a 75 meter dipole antenna. What a fun radio to have and use. Way to go MFJ.
W0ACE Rating: 2011-12-16
Replacement radio works perfect!! Time Owned: 0 to 3 months.
Ordered a MFJ-9420 transceiver, matching MFJ-971 tuner, and MFJ-4114 power supply from AES. Upon working my first station I was told of a BAD squeal on transmit. I listened on another rig and sure enough! I sent it back to AES the next day and they replaced it with another. It works fine business. I have worked several DX stations with only 10 watts using a homebrew inverted vee dipole 15' high. Has great receive audio, 1/4" headphone jack. I love my little station now! Will post a follow up review after further use, planning some portable. 73's w0ace
KATEKEBO Rating: 2011-09-16
Review 1 - Good radio, but manufacturing quality is an issue Time Owned: 3 to 6 months.
This is the first of my two consecutive reviews of the same radio (MFJ-9420). Instead of writing just one review mixing the two aspects (radio and manufacturer), I decided that I will write two reviews to fairly reflect my impressions with both.

I love this radio. It’s very simple to use and performs very well for its price and specifications. It does exactly what I expected from it. It is also very easy to align and maintain using simple tools (a DMM, a wattmeter, a dummy load and another digitally synthesized transceiver as frequency reference). Older, ‘through-hole” assembly technique radios are easier to repair and seem to hold alignment better than newer, SMT-components radios.

The only watch-out is that a novice ham may find the radio a little bit more challenging because of the alignment requirements. On the other hand, it offers an excellent opportunity to learn SSB xcvr basics.

KD7RDZI2 Rating: 2011-09-13
Prepotent QRP Time Owned: 0 to 3 months.
I could not resist to get one MFJ-9406 in mint conditions at a hamfest. Transmitting into a dummy load I listened to my Drake R8 with VHF converter to check my modulation. It was great, really punchy for dx, with the cheapest dynamic microphone on earth. I regulated the internal trimpot for ALC. That was it. I see 8 watts on an average wattmeter on my speak peaks. Speech processor is very well designed. It drifts a bit on warm-up. Using my allegedly low efficient HF antenna, a T2FD by B&W, I went on air. SWR was at 2:1. Again I could see 6 to 8 watts on my agerage wattmeter on my speak. In the first 15 minutes I had 6 qso! Not to bad. Now I just look forward for dx openings.