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Reviews For: AB5N - Icom HM-151 - IC-7000 mic. modification

Category: Microphones for ham radio

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Review Summary For : AB5N - Icom HM-151 - IC-7000 mic. modification
Reviews: 159MSRP: 39.50
Modification to the Icom HM-151 hand microphone that comes with the Icom IC-7000. This mod fixes the poor FM audio that this microphone and radio combination has from the factory. The modification replaces the mic element and a capacitor, adds a shaped acoustic foam shell, widens the mic opening, adds a wind screen (pop filter) and a 1oz weight to the microphone shell.
Product is in production
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# last 180 days Avg. Rating last 180 days Total reviews Avg. overall rating
KJ6WKH Rating: 2012-09-29
Essential for voice comms Time Owned: 0 to 3 months.
The first night I used my new-to-me IC-7000 (with a more recent "made in China" HM-151) on a local repeater, I got poor audio quality reports. Despite making mic gain changes, the situation didn't improve.

I looked online and found AB5N's HM-151 modification website and liked the straightforward presentation and simple instructions. The YouTube audio clips cinched it -- there's a clear difference you can hear.

Turnaround time was longer than I expected but I had a camping trip planned and then got the flu so it wasn't really missed. Bob let me know when it was shipped and it arrived on time.

I finally got to try it today and got much improved audio reports on SSB and FM; compression on & set to 2 with 30% mic gain. The larger hole for the mic element is clean and without burrs or scratches. I opted for the 1oz weight and it gives the mic a nice heft and doesn't feel slippery anymore.

I'd definitely recommend this modification to anybody with complaints about the stock mic. It works. Thanks, Bob!

73 Chris KJ6WKH
M6GOM Rating: 2012-05-07
Update to earlier review Time Owned: 0 to 3 months.
Given all the 5 ratings, I had a think about it and thought there may be a chance there was something wrong with the one I had which came already fitted to the radio. Being in the UK, Bob ships the kit out. For the price it was - basically £20, it was worth a try ordering one from Bob and replacing the one in the converted mic I got with the radio. At worst, I'd be £20 down plus a bit of my time.

About 10 days after ordering it turned up - quite good from the USA - and was duly fitted.

I've been running it for the last few weeks and it seems infinitely better than the original one that was in there. No problems on FM, none of the other issues I had in the review below. Still have to have the mic gain right down and you can't run compression whilst mobile but then again, Bob covers that in the DVD and elsewhere and TBH not being able run compression hasn't caused any problems.

There is one major difference between the one I replaced and the one I fitted and that is the capacitor. In the kit I got there are two capacitors supplied - one for base use, one for mobile. Without taking it to bits, it looks like Bob has fitted another component in line with the cap and covered them with heat shrink. I have no idea what the component is without taking it apart but it definitely helps for mobile.

The Icom 7000 I have is one of the very first ones so I have no idea how old the original AB5N mike mod was so some of the improvement could be down to the type 2 element being used and some down to the modified capacitor for mobile use.

Very happy now. My only recommendation is that if you are going to be using this mobile at all, make sure the mobile option for the capacitor replacement is installed.

Earlier 1-star review posted by M6GOM on 2012-04-01

I bought an Icom 7000 that already had a mike with the AB5N mod in. IMO it absolutely destroys this microphone. Compared to a standard one, the AB5N mod wrecks the noise cancelling if you use it when mobile. It is also almost impossible to use the processor on SSB without the ALC being overdriven even with the mic gain down to single digits. It also causes issues on FM giving an effect similar to being in an empty room.

This is all experienced on a fully aligned radio. Changing the mike to a standard unmodified one solved all the problems. With the unmodified one the problem disappeared. I use my mike gain on 32 with the standard mike.

This mod seems to be aimed at the less than competent amateurs who on other radios would whack loads of bass into their audio which destroys the intelligibility because they want to see the TX power meter pegging the 100 mark all the time. These are the same amateurs who use a standard power meter instead of a proper peak hold meter to measure SSB and think their SSB power output is low.
WA6QGH Rating: 2012-04-23
Great Modification Time Owned: 0 to 3 months.
I had chance to compare transmit audio with my modified HM-151 on my IC-7000 to my IC-7600 with SM-20 mike. Both radios during comparison tests had mid TBW 200-2800 with compression setting 1 on IC-7600 and 3 on IC-7000. In 9 out 10 checks the stations on other end thought IC-7000 had slightly better sounding audio response than IC-7600. Both radios got excellent transmit audio quality comments. Note all the tests were done on SSB 10,15, 20 & 40 meters. I would highly recommend this modification done by Bob AB5N.
ZS5J Rating: 2012-02-18
Outstanding Time Owned: 0 to 3 months.
I have three IC-7000 radio's with their respective HM-151 microphones, and have read the glowing reports on Bob's work here on eHam, but have always put off getting my mic's modified by Bob, mostly because of distance and worry that the mic's would end up getting lost in the mail.

I took the plunge a few weeks ago, and must say that I am thrilled with the entire experience. I sent off two "made in Japan" HM-151's - I decided to not have have my "made in China" HM-151 modified, as it is slightly improved over the made in Japan mic's. In hindsight I should have had that one modified by Bob also.

The entire experience was absolutely first class - from the excellent information on Bob's website, to audio samples provided, to feedback here on eHam. Then the fast work by Bob - he received my mic's, repaired them and had them shipped back on the same day. To the excellent communication by Bob - friendly, helpful, obliging and responsive. To the finished product - I have done numerous tests, and conclude that this mod by Bob has made a vast improvement. I now only need to run the mic gain at 45 % (previously I had to run at 90 % to generate proper ALC levels). The audio sounds much better with the new element - not as restricted or tunneled as before, the weight of the mic is also now perfect with his included weight mod. I nice touch, is that he returns the old components that he removed from the mic.

Bob is your go-to guy for everyone that owns an Icom IC-7000 and HM-151 microphone. This mod is a must. You only need look at all the 5/5 reviews here, to appreciate the quality of Bob's work.

John, ZS5J
MM0MUN Rating: 2012-01-24
Great upgrade Time Owned: 0 to 3 months.
Great service, 21 day turnaround from Scotland and that was over the Xmas and New Year holiday! The results? Just amazing, Im getting reports like "great modulation" "Booming in here" "really punchy audio" etc etc! The best £££s iv spent since I bought the 7000.
If you have an IC 7000 get the mic shipped out to Bob you wont regret it Im sure.

Thanks again Bob 73s Eddie MM0MUN
GI0ZGB Rating: 2012-01-13
Mic Magic Time Owned: 0 to 3 months.
I ordered the component parts from Bob, took a look at his excellent installation video and had the mod fitted and mic up and running in less than twenty-five minutes. We then conducted comparison tests with a standard HM-151 and the difference was like day and night, especially noticeable on FM.To say I was pleased would be an understatement, I only hope Icom are listening and learning.
I thoroughly recommend this modification, for it makes a good sounding rig even better.
ZL1KAN Rating: 2011-12-26
Bobs Mod to HM-151 Mic Time Owned: 0 to 3 months.
Bob well done again, I'm a Satisified Icom-7000 owner with the excellent reports from overseas QSO's with the mod.
Should have done the Mod when I got the Rig last Year Now I know what I missed out on.

The Mic settings you provide are magic.
All Icom -7000 owners should get this Mod you wont be disappointed.

Thanks Bob 73's ZL1KAN
K5AGO Rating: 2011-12-15
Exceeded Expectations Time Owned: 0 to 3 months.
I had high expectations given all the great eHam reviews and even those expectations were exceeded. Bob kept me in the loop every step of the way, provided same day service and my comparison tests of before and after show a remarkable improvement. I am a very satisfied customer.
N2HUC Rating: 2011-11-23
Great Audio at a Great Price! Time Owned: 3 to 6 months.
I purchased an Icom IC-7000 last summer and read all the reviews on the radio and the stock microphone audio issues prior to my purchase. Those poor audio and drive reports were all true. The radio is absolutely fantastic with all those useful features and bands, so much so that I’m having trouble finding a matching base rig to beat it, but the audio and drive on the stock mic was really poor to the point that no one really wanted to QSO with me. No radio settings or advised adjustments helped much at all, if any. I stopped operating until I could get a chance to do the AB5N microphone modification. The wait was killing me!

AB5N gave many good examples of audio improvement on his site and on YouTube, so I felt confident it was well worth the price and decided to give it a try. He was on vacation for that month when I was ready to order, and I wanted to operate very badly. I contacted him and he was willing to sell me a kit due to my experience with SMD component level repair. He provided overkill video instructions on an included CD, but I welcomed that over nothing. No questions should be left after those thorough instructions. The mod was easy to do and the kit was complete with ballast for weighting the mic, if you so desire. I used a few of the supplied BB’s and shot the rest (hi hi).

(Now for the moment of truth.) "You are mobile?" "You sound like a home station.(many bands)" "That is the best mobile I have ever heard! (75m)" "Are you running extra power?" "100 watts, really? (75m/40m)" "What microphone are you using?" "Sounds as good as all the studio mics and external EQ’s and compressors around here (40m ragchew net)." "I wish my mobile did that well (10m DX into Ireland)". "Where can I get that mod? (too many to list)" These unsolicited reports are very common from my contacts on all bands from 75m to 10m. People go out of their way to ask me what I am using and where they can get it. I went from zero to hero overnight (hi hi). I can now hang on 40m and 75m with just my 100 watt mobile and High Sierra HS-1500 antenna! DX is also very easy. If I hear it, I can work it. Ragchews for hours on 10m down to 17m. HK3C (formally HK3OZ) immediately picked up on the sound of the mic mod and knew I did the mod. His comment was, "Everyone with a 7000 should do this mod. It sounds great." Signal reports also went way up, as every watt of the 100 watts is being used throughout the passband. No audio spectrum dead frequency areas...just full and robust audio. My previous S6 reports became the very common S9 reports I now get. I heard a couple of recordings someone made on their station and I could not believe that was my station I was hearing played back. Strapping "broadcast quality" audio on my wide setting and clean balanced punch on my compressor setting.

About settings...I set my three TX BW filters for full, punch and contest or pileup buster operation. I adjusted the mic gain to what many people reported as "right there". A few times I lowered it slightly without announcement and that drop was noticed, so it went back to the sweet spot. Compression is really not needed, but a touch gets you "to 11 for that extra push over the cliff" when you need it (on average, 1 S unit higher). It picks up a bit of road noise, so I don’t use it while moving much. It is a pileup buster with my voice keyer callsign memory recorded at 16" away from the mic on the MID setting transmitted with the processor on. The voice keyer recorder has forced compression while recording and also uses the TBW setting you select, so saying "check" a couple of times prior to recording, and recording at some distance produces clearer keyer recordings. If you record set on MID TBW, then you get MID audio on playback. Here are my stored settings that have proven successful:

WIDE 100-2900 gain = 80 comp off
MID 200-2900 gain = 80 comp 1 12" away
NAR 300-2900 gain = 80 comp 1 12" away

NOTES: The NAR setting doesn’t work better than the MID setting because too much voice fundamental is cut off on the low end. I rarely use it. Most stations report the WIDE setting sounds best, and I talk across the front of the mic about 2" away, and not directly into the mic. The power out meter really nails a full 100 watts with this setup, without distortion or unnecessary breath noise. ALC is well in the zone. Many also report the MID setting sounds good too, but prefer the WIDE setting for full robust audio. Using the MID setting with compression set to the lowest level above zero (1), and talking 12" away from the mic produces less "broadcast" quality low frequency, but adds great punch. It still has plenty of fullness. NAR is too thin. One other thing I discovered about the radio is that it saves the last used TBW filter selection for COMP on and COMP off, so I selected MID for COMP on and WIDE for COMP off. The F2 button on the mic has been programmed to toggle between comp on/off. (F1 for TONE selections) I’m done with microphone setup, and operating with a strong clear signal. Nothing left to adjust. Just perfect!

A big thanks to Bob Nagy (AB5N), who did a great job engineering perfect microphone audio for the 7000. No need for us to try hundreds of combos to see what works. I would buy a mic mod for every one of my radios if Bob engineered them (come on can do it!). And the price is very fair with top-notch support and service. You will like it. :)
VE3BDE Rating: 2011-10-31
Outstandig A++++ Time Owned: 6 to 12 months.
Super Fast results,outstanding service I highly recommend Bob's modification for the HM-151
Now all my reports are 59+20db super clean audio everybody ask me what kind the radio and mic I use.
Bob you are a genius my friend.Icom should reward you!!!God Bless you and 73'Gabriel VE3BDE