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Reviews For: Mirage BD-35 Dual Band HT Amplifier (144/440)

Category: Amplifiers: RF Power - 6M/VHF/UHF+

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Review Summary For : Mirage BD-35 Dual Band HT Amplifier (144/440)
Reviews: 29MSRP: 159.95
Description:
The Mirage Dual Band Handheld Amplifier, which includes the 144/440 MHz segments. At 1-7 watts in, it will put out 45/35 watts respectively. It is also capable of full duplex operation, allowing the user to transmit on one band and listen on the other - provided that the handheld you're using is capable of this function. Listed frequency ranges are 144-146 on 2 meters and 430-450 on 70 centimeters. It is described as having an automatic band select, on-air indicator, and reverse polarity protection.
Product is in production
More Info: http://www.mirageamp.com/mirageamp/products.php?prodid=BD-35
# last 180 days Avg. Rating last 180 days Total reviews Avg. overall rating
00293.8
KJ4FGI Rating: 2011-03-24
Good Amp Time Owned: more than 12 months.
Had it in the car to complement my HT worked great than put it in the house using a Diamond base antenna, great again, I am now using it portable coupled to a 12 volt portable battery for satellite work out in the yard. again works great, had it for three years now. Very versatile.

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Earlier 5-star review posted by KJ4FGI on 2010-09-01

I use this amp in my Mobil with a Yaesu Ft-60r, it might not be as good as a dedicated 2m or 440 radio but it gives me the option to take my Yaesu FT-60 out of my vehicle for HT use alone or take the amp and radio from my car add 10 feet of cable to my removable auto antenna put it up in a tree by fishing line (like one would do at a picnic) plug it into mu battery pack and I'm getting great repeater coverage. The portable aspect of this concept is being creative and portability whether a quick release for Hand Held or portable base station for fun or emergency.
GD1MIP Rating: 2010-12-22
Average Time Owned: 3 to 6 months.
Bought from a stall at a hamfest to add to my FT817 in the car. I did not even unpack it for 6 months due to a change in circumstances.
I got it out this week and found no TX OP on VHF, UHF was fine. On investigation I found the preset variable capacitor plates were stuck together. One new Vari cap restored it to working order. By then I realised it was class C and I need it for SSB so its off to ebay. Can't help being concerned re quality control.
N5DXL Rating: 2010-04-26
Mirage/MF "Mississippi's Finest Junk" Time Owned: 3 to 6 months.
Oaky the Mirage BD-35 as we all know is made by MFJ now first
of all I can not say it's all MFJ "Mississippi's Finest Junk"
as I got the amp used off of QRZ. As soon a I received the amp
I found it was dead, double checked everything and still couldn't
get it to power up. Tried to call seller and his phone had been
turned off, tried emailing and needless to say no answer he was
gone in the wind. So I shipped the amp off to Mirage/MFJ and $60
later I got it back. put it in my pickup and yes it did work the
1st and 2nd day. On the 3rd day I couldn't get it to power up,
checked everything and it was dead. Now it was only used maybe
15 minutes before both days
Got hold of Mirage/MFJ and they. said to ship it back. I am still
waiting for them to return it. Once I get it back I'll do a test
then set it on a shelf were it'll stay.
I know MFJ makes a lot of stuff some good and more not so good.
I am very happy with my MFJ-259B ever a my MFJ-989D tuner before
ever hooking it up I found cold solder joints and had to spend
2 hours just going over it before I would even try to test it.
What do I think of MFJ "Mississippi's Finest Junk", it's better
to spend a few more dollars and get something that works as it
should. I'll do my best to stay away from MFJ at all cost.
KB3DVS Rating: 2010-04-09
Doesn't work for me. Can't get it fixed. Time Owned: 6 to 12 months.
I purchased a Mirage BD-35 RF amp for HT's that I found was not working properly. I couldn't get it to light up and amplify, though power seemed to be working fine.

Sent to MFJ, they "repaired" it. This means $2.04 in parts (a capacitor and a trimmer cap) and a $62 bill.

I got it back and tried to use it again, connecting it to one HT (an older Icom Z1A) I could hit the local repeater on key up and the amplify light glowed bright on the BD-35. Tried to key up a second time and it wouldn't work. HT indicated full output power but it wasn't tripping the BD-35 into amplify.

Put a meter on the HT and the output power had been reduced to about half a watt, on high power. Low power barely moved the needle on the RF meter.

Thinking this was odd, I dug out my trusty Yaesu VX-5R. I can sometimes hit repeaters with this by itself, so adding the amp should make this a cakewalk.

First key up was solid. Then I couldn't get the radio to light up the amplify light on the BD-35. Fearing the worst, I connected my HT to the meter and saw the output had been terminated just like on the Z1A. I was furious.

The repaired amp had ruined two good HT's.

I called MFJ. They said send it back in, I wanted a refund on my repair because they had clearly not troubleshooted this amp properly and it ruined my gear. Moreover, I couldn't ever see myself hooking anything else up to the BD-35 for rear of it ruining that gear too.

I spoke with Bob Ellis, in Service, several times over weeks, to no satisfaction. He said to send a letter to MFJ president Martin Jue, which I did, and never received a reply. I called Mr. Jue's office and was handed off to Richard Stubbs, in Customer Service, who flat out told me that he told Bob to take of this. They would do nothing but send my amp back to me. I tried to explain that the repair I paid for was bad, that I wanted my money back– but as I was speaking, Mr. Stubbs said that he would send my amp back, goodbye, and he hung up on me while I was speaking.

I called back and left a message on Martin Jue's voice mail but after several days it has had the same zero response as the letter I wrote him. I've since received the amp back, and the service note says it was tested and required no repair.

I don't want the amp. I have no more HT's to even try and amplify. The two I have don't produce enough RF to make the amp work. I wanted my repair money back. I wanted them to take back the amp. They did neither.

So anyone who wants a BD-35, e-mail me. You can have it at a really good price. I'm not an engineer and it probably has some electrical or technical issue that I don't have the time or wherewithal to diagnose and repair. Many have good results with it. It may be a good amp. But MFJ damm sure can't repair & test it right and I damm sure ain't going to hook it up to anything else I own.
KK9H Rating: 2010-03-17
Update, still positive Time Owned: more than 12 months.
I changed the low power setting on my IC-91AD from 500mw to approximately 1.5 watts for both bands to create a reasonable level of power output from my BD-35 without overheating the 91AD during normal conversation. Next, I measured the power output from the BD-35 into a dummy load. On 146.00 the reading was 38 watts out and on 446.0 the reading was 22 watts out. With the 91AD set to high power the BD-35 measured 45 and 35 watts out respectively which are right on spec. I have my BD-35 connected right to the car battery and I remain very pleased with it.
KB0NE Rating: 2010-02-24
MFJ has changed the formula Time Owned: 0 to 3 months.
Whenever I buy a 'factory built' I expect the product to work fine out of the box. This is not the case with the Mirage BD-35 manufactured by MFJ.

I own several bits of MFJ gear and have been very satisfied with their quality VS cost. This isn't a rant against MFJ but rather a observation of how this amp works.

I wanted to install the amp in my vehicle but due to the bad winter weather here in Colorado I was stalled in getting this done. Other wise I would have returned it promptly but was really too late to return to the distributor.

First the pros: It appears to work OK at room temperature. Unsure about spectral purity, however. (see cons)

After hooking up the amplifier in the car, using my VX7 HT to drive it, and good dual band antenna (swr checks very low both 2m and 450mhz) the amplifier put out plenty of power with 5 watts drive from the HT. I was able to hit fairly distant repeaters and didn't have any reports of poor signal quality. Keep in mind that the car and the amp were both reasonably warm at this time.
Leaving the amp in the car overnight and the temperature dropping down to about 40 degrees Fahrenheit I connected the warm HT to the amp and was greeted with the indecision by the amp of which band I was on.... so the amp light up both the UHF and VHF lights. NOT GOOD. I tried a few more times and nothing changed. After driving a few minutes the problem stopped but I got yelled at by folks on the local 450 repeater saying that my signal was horrid. Turning off the amp all was much fine just with my unamplified HT.

The next morning it was close to 30 degrees F and i turned on the amp again.... this time it decided that it needed to self excite, both UHF and VHF lamps turned on the I could hear the relays buzzing. WAY NOT GOOD!

Anyhow, I contacted KO3U, a previous reviewer here, who was having bad luck with the BD-35. He verified my observations about the amp needing to be warm in order to operate properly.

Hoping to get a better schematic drawing than the one a helpful ham had sent me I got a schematic directly from Mirage (much to their credit for promptness *but* the quality of the schematic is bordering on unreadable) it is obvious that the original BD-35 had a 2SC????(unreadable) bipolar transistor in the PA section. My BD-35 has a MITSUBISHI RF POWER MOS FET, RD70HVF1 in it. While this part is an acceptable substitute gain and frequency wise, it is not a direct substitute for a bipolar part because of different input and output complex impedance of the parts themselves.

After talking to my pal Gary, KG0SI, who had tons of experience with all types of RF amplifiers that range up into the microwave frequencies.... MOS FETS need thermal compensation in order to stabilize the bias over any temperature swing. I see no indication that there is any type of compensation in the BD-35.

As far as spectral purity goes, this bit of extra engineering may not have been done either. So it's off the the races to reverse and re-engineer something that should have been done right to begin with.

Now the Cons: This isn't an amp that can take cold weather. It may work OK in a warm shack but with the obvious substitution of the PA amp I wonder whether or not the PA device is properly matched to the circuit and producing clean RF signals when it is warm since it obviously does not do so when cold.
K2DSL Rating: 2008-06-01
Works just like it should Time Owned: 3 to 6 months.
The only issue I had with the BD-35 was finding one. Seems to be tough to come by, even when trying to order it online or through actual store fronts. My extremely reliable local dealer kept expecting them to come in, but they just never did.

I finally found one a used on eBay for a good price and bought it. It works extremely well allowing me to hit repeaters I can't hit with my TH-D7A(G) dual band HT on its own. I use it inside my home hooked up to a nice Diamond X200A antenna and in my vehicle connected to a magnetic roof mount dual band antenna. It's easy to move around.

No reason not to get one. That is, if you can find one!
K1MBR Rating: 2008-03-16
Still Going STRONG!! Time Owned: more than 12 months.
I bought this amp over 15 years ago (I think). I've used it in my service vehicle all this time. It allows me to use a securable dual band HT but give me the power of a mobile. I use mostly UHF but this has the ability to get through on the Weather Net on VHF during storms. I worried about it over heating because of it's small size when I first got it and was going to add a few small fans, but it has never needed them and it has never failed me. I have been through 6 different HT's but still have this original amp. Dayton Hamvention is comming up soon and I really should get one for a emergency kit. This has been a spectacular amp for the money!

500 mw in will get you about 4 to 6 watts out but as I discovered you must NOT use an RG174 pigtail to feed it. I have mentioned this amp in other reviews but have been sadly remiss in doing a review on this wonderful piece of equipment.

Larry K1MBR
KPAX1 Rating: 2007-06-20
Great little Amp Time Owned: 3 to 6 months.
I bought this at Universal Radio for $159. A very good investment. Now I do not need the older VHF and UHF Amps anymore. This does it all. VHF mode will amplify up to 50 WATTS with just 5 WATTS from my FT-60. I get 25 WATTS with just .5 WATTS input. Really saves my HT battery.

On UHF, the amp would not respond to .5 WATTS input. Probably would with 1 WATT. My FT-60 with mid setting of 2 WATTS produced 25 WATTS output and 38 WATTS at 5 WATTS input.
At such a small unit and a great price, I look forward to many years of great performance from this little jewel.
W2MSK Rating: 2007-02-07
Good amp because not from MFJ Time Owned: more than 12 months.
Nice amp, good power output and stable. The reason this is rated highly is that Mirage or MFJ did not design nor manufactuers it. It's imported from Taiwan where they respect quality and the customer.