FM deviation and Audio Quality Posted by: "Bob Nagy" rjnagy@gmail.com yavor55 Date: Fri Jul 28, 2006 4:44 pm (PDT) Greetings all- Well, for those of you that have the same sentiment as I do about the FM audio quality and marginal deviation - For those of you that just hate to shout into the mic, I spent the day working on the HM-151 mic and got it working swell. Yes, the 7000 is capable of pretty decent audio on FM. It's not as good as a 706, but I got glowing reports on FM and SSB after the mod. I followed K6HTM's file on modding the coupling cap in the mic - going from 1up to .2uf. You can use a small .22 or two .1's parallelled. That will roll off the bass so that the overall response is more balanced. You still need more gain though. I started going through every condenser mic element I could crib from old mics. The space is small in there, but most fit just fine. I found that an old element from a 80's vintage Yaesu hand mic worked quite well. It has more highs and more drive. I then heard a member say that the old HM-103 stock mic from the IC-706 sounded "Brilliant". I happen to have one, tried it, and oh yea, it sounded punchy, clear and had plenty of output. It was a night and day difference. It is what you expected from the 7000. I had to have the functions of the 151 mic, so I sliced away at the case and silicone pad till the 103's element fit in there. The 103's element is very large and really JUST BARELY fits with pretty drastic surgery. Now, I have almost too much drive. I can run the mic level at 1% and modulate on SSB to half output (with comp on). The sweet spot is around 25%...comp on 1. I suggest that you techs out there change the cap as on K6HTM's file (in Adam's file section) and then experiment with condenser elements you have and can get. They are cheap...try several. (smaller ones) I don't suggest using the 103's element, as the size is a problem. You can definitely find one that works 100% better than the stock one. Also, watch Bob Heil for his upcoming EQ mic and mic elements. I went from totally dismayed this morning - to totally happy. This rig CAN produce decent audio on FM. It's absolutely worth the effort. Bob AB5N PS: you can also always just use an HM-103! ======================================================================== HM-151 Mic Audio Problem Fixed - Finally! Posted by: "yavor55" rjnagy@gmail.com yavor55 Date: Thu Sep 7, 2006 10:06 am (PDT) Greetings everyone- I'm here to announce that I have engineered the fix for the HM-151 mic low audio problem. I took a month to dial-in the right components...new mic element..blocking capacitor and a few mechanical mods. The results are excellent and I'm glad this one will be behind us. My ham buddies suggested I offer to mod other folks mics (as the surface-mount cap and mic element are a bit difficult to work with. I've made a simple website to give you more details. www.7000mic.com 73's for now- Bob AB5N Hot Springs ======================================================================== HM-151 microphone upgrade coming Posted by: "Scott Schoemann" sschoemann@wi.rr.com n9tgw Date: Fri Sep 8, 2006 11:00 am (PDT) "Damn the tone, full speed ahead!" to paraphrase a famous quote. The only problem with the HM-151 is that it doesn't come in a desktop version. Everyone that is complaining about it's audio quality needs to HEAR it for themselves. And stop relying on others. You don't know what they think sounds good, the acoustics of their installation or the audio response of the speaker they are using. Having two hams in the household, and KNOWING the mobile installation as well as I do since I set it up myself to accommodate the noises encountered when running off road, I have heard every tonal inflection of my daughters trained choral voice come through the HM-151 while at the same time hear another ham proclaim that her audio was "muddy" the second he found out she was using a 7000. Reports from people who I know and speak with face to face regularly are always positive. The disgruntled seem to complain about everyone's audio. Perhaps some people don't know how to use the mic properly as it is very sensitive and if you "get up on it" with the gain turned up it will sound bad. I run my gain at 100% (YES WIDE OPEN), mike to the SIDE (no sibilant or plosives hitting the mic) and a minimum of 6 to 8 inches from my face. This is the way I taught my daughter to use the 7000 and I would say that I get over 95% positive reports on my (our) audio using the "stock mic", on both FM and sideband, while adjusting the compressor to stay with in the agc limits. And above all, remember to talk in a normal voice, don't yell, shout or raise your voice while transmitting. THAT WILL distort every time. Scott N9TGW ======================================================================== HM-151 microphone upgrade coming Posted by: "pjdemas" pdemas@twcny.rr.com pjdemas Date: Fri Sep 8, 2006 12:47 pm (PDT) I agree! Although I do not use your settings I have found the sweet spot for my operating style and voice characteristcs. (Mic Gain of 14%; Compression of "4"; TBW maximized to rigs high and low end). I have received excellent reports! At his point a desk top verion of the Stock Microphone with full functionality would be great! Not sure if adding a "Heil" type Microphone is really going to benefit much. > ======================================================================== HM-151 microphone upgrade coming Posted by: "Kjell Karlsen" la2ni@online.no la2nikjell Date: Fri Sep 8, 2006 2:28 pm (PDT) Hi all. I agree with you Scott. The mike is good enough for SSB and even for FM. I have run a 2-tone test of the IC7000 without compression and with it on. The spectrum with 100W PEP output at 14V supply, shows 40 dB attenuation for Ip3 and Ip5 distortion, witch is very good. With the compressor ON at 20dB , Ip3 and Ip5 goes up to -32 and -33 dB. The higher Ip orders does not go up at all and I can see no other distortion coming up inside a BW of 4 KHz. Looking at the 2-tone signal on the oscilloscope shows a small distortion on the peak envelope, but no "flat topping". Looking at the scope when speaking, there is no evidence of "flat topping" even with the mike gain and compression turned fully up. The ALC peaks up a little outside the limit, but I have never had any reports telling about distortion. I have measured in the same way on several stations, (ICOM, Yaesu, Kenwood and home made with "real RF Clipping") and the IC7000 is one of the best I have seen. I belive ICOM has done the Compression by programming "RF Clipping" in the DSP. I really look forward to see what will come up in the next years in DSP transceivers. With all the new DDS chips from Analog Devices and AD converters and DSP processors from several companies, I think we will see a radio without any "Roofing filters" at all in the near future. 73 es LA2NI Kjell. ======================================================================== HM-151 microphone upgrade coming Posted by: "RAY" Rcostell3@comcast.net ray_costello Date: Fri Sep 8, 2006 2:32 pm (PDT) Maybe we need to add a section to QSL Cards that allows rating voice quality. It might surprise some people that have never heard their voice on the air. 73, Ray, N0FY ======================================================================== HM-151 microphone upgrade coming Posted by: "ahac.geo" ahac.geo@yahoo.com ahac.geo Date: Fri Sep 8, 2006 3:20 pm (PDT) Hi! I do not say that modulation produced by IC-7k is unusable or utter crap. But what I can definitely say is that is should be better than it is and Icom should produce a correction (in hardware or in software for DSP) for future revisions of this otherwise great RTX. Of course I also agree in the saying mentioned below regarding the ear of the beholder. :) 73 de S56OA - Ognjen ======================================================================== HM-151 microphone upgrade coming Posted by: "D C *Mac* Macdonald" k2gkk@hotmail.com k2gkk Date: Fri Sep 8, 2006 7:45 pm (PDT) That microphone technique may be all fine and good in a quiet hamshack with good sound absorbing stuff around, but it will be totally unsatisfactory in a mobile environment. Background noise will probably be at almost the same level as the voice and that inherent noise will cause the speaker to raise his/her own voice to levels that will result in "muddy" sound. Mac - K2GKK/5 ======================================================================== HM-151 microphone upgrade coming HM-151 Mic Upgrade Works great1 Posted by: "Michael Aust" ava622@verizon.net mikeatthebeach1 Date: Thu Sep 14, 2006 7:22 am (PDT) Bob, Received my newly upgraded HM-151 microphone for the IC-7000 from you just the other day. WOW! what a difference in the sound! I have been getting excellent audio reports on FM. No more reports of hollow boxy sound audio. Also the level is better since you changed out the old mic elecret element with the higher voltage one. In addition, reshaping the audio with the new coupling capacitor really helps the sound of the audio. Th average voice were previously 3KHz and now between 3.5 to 3.7KHz., seems to be now just right compared to my other FM rigs. The maximum peak deviation is just under 5KHz (4.8KHz) with no distortion. The DSP limits the maximum deviation so no way to over deviate your signal. Had no problems in the mobile, no background noise as some might have suspected gong from a noise cancel elecret element to the the non noise cancel elecret mic element. Reports on SSB have been great. My Mic setings are now at 50% and I easily can attain 100% output power on peaks without the compressor. Anyone that wishes to get rid of that boxy hollow sound with the HM-151 should get the HM-151 Mic Upgrade. It is well money spent! Now my IC-7000 sounds great on transmit for both FM and SSB. I still believe Icom should allow Mic Equalization on Transmit since each microphone is different and the user can adjust for their best tastes, they can always have the defaults (DEF) settings in the menu in case one does not adjust properly. My new upgraded HM-151 looks great, Bob's (AB5N) workmanship is super and took my Mic down to HRO and did a comparison between a stock Mic and the Upgraded Mic. A big difference especially is on the 5KHz FM repeaters here in the U.S. The HRO dealer could not tell the difference physically between a stock HM-151 and the Upgraded MIc. He wanted to know how he could get one since he also has an Icom IC-7000 and has similar issues with the hollow boxy low deviation problem n FM! I believe Icom should put the Mic Equalizer back into the IC-7000, as long as there were default settings to return to in case one did not like their own adjustments. If there was a way to reactivate this within the IC-7000 with a mod (diode change) , I be willing to beta test it for them. Again, Bob thanks for the great Upgrade, got my Mic in less than two days! You reseaching of over a dozen Mic elements tried on the IC-7000 paid off big time! Thanks for the great service you provide for us IC-7000 users.This was the best $30 dollars spent for my IC-7000, now it's a great radio!! Icom should contact you to learn how to improve the sound of the IC-7000, hopefully they could get you the mod for reactivating the Mic Equalizer for the IC-7000 since you are a Sound Engineer in the broadcast business, you certainly know your stuff! The new Mic sounds as good as my Heil Handy Mic with the HC-5 element! Watch out Heil Sound, Bob (AB5N) is catching up with you! Now I have a great souding HM-151 with all the features and controls intact on the HM-151 compared to the Heil Handy Mic with no controls! Mike WB6DJI P.S. see Bob Nagy's link (AB5N) link for the HM-151 Microphone Upgrade. http://www.7000mic.com (HM-151 Upgrade / Fix) ======================================================================== HM-151 microphone upgrade coming HM-151 Mic Upgrade Works great1 Posted by: "Adam Farson" farson@shaw.ca va7oj Date: Thu Sep 14, 2006 10:00 am (PDT) Hi Mike, I concur with you 100% on the omission of the TX audio equalisation menu from the IC-7000. There is no "diode mod" to reinstate it; the required code was simply omitted from the DSP firmware. The radio will not transmit out to 3.7 kHz on SSB. The maximum value of the high -6dB point in the SSB TX audio response is 2.9 kHz. This is hard-coded in the DSP, and has been confirmed by lab tests. Cheers for now, 73, Adam VA7OJ/AB4OJ ======================================================================== HM-151 microphone upgrade coming HM-151 Mic Upgrade Works great1 Posted by: "dietmarfichter" dfichter@uwo.ca dietmarfichter Date: Thu Sep 14, 2006 11:12 am (PDT) > The average voice were previously 3KHz and now between 3.5 to 3.7KHz This is interesting about the audio frequency response. However, in a posting Adam Farson he states: that the 7000 TX audio frquency response is hard fixed by the DSP at 2.9 KHz at 6 db, confirned in lab testing. If indeed this is the case then the improved wider audio frequency response(3.5-3.9KHz) from the new mic will be attenuated at 2.9KHz by the DSP and the high audio frquencies will be even further down at 3.5 KHz. The qualty of TX audio should not improve. Dietmar VE3CG ======================================================================== HM-151 microphone upgrade coming HM-151 Mic Upgrade Works great1 Posted by: "pe1jlj" imapbox@xs4all.nl pe1jlj Date: Thu Sep 14, 2006 11:46 am (PDT) --- In ic7000@yahoogroups.com, "dietmarfichter" wrote: > If indeed this is the case then the improved wider audio frequency > response(3.5-3.9KHz) from the new mic will be attenuated at 2.9KHz by > the DSP and the high audio frquencies will be even further down at 3.5 > KHz. The qualty of TX audio should not improve. Bob shoudl post both original and modified soundfiles. So far I have been talking to quite a few people and nobody said my modulation was boxed, hard to read etc. So give us some examples on an unmodifed mike and a modified one. ======================================================================== HM-151 microphone upgrade coming HM-151 Mic Upgrade Works great! Posted by: "yavor55" rjnagy@gmail.com yavor55 Date: Thu Sep 14, 2006 9:57 pm (PDT) Mike- I am sooo happy you are satisfied. I take the work very seriously and am glad to be able to make our experience with the 7000 better. I did not post "before" files because...actually..I just didn't think of it. The main big difference is a level boost - bringing that FM deviation up out of the 3khz average region into the 4-5khz region. That won't represent well on an audio file. Possibly the SSB "before" file would be more revealing. Computer speakers are far from ideal in representing what you get from a Ham receiver(they work badly as external ham speakers). If I get a break from upgrades, maybe I'll record one. The bass trimming really helps "un-muddy" the audio in SSB. On FM, that has almost no effect. The hollow-ness is caused both by the DSP and the mic. We can only address the mic now, so what I've done is to kill the shell's resonance with the acoustic foam. I also suspend the new mic element off the circuit board -isolating it from the sound conduction through the board (all good mic elements are suspended). Thirdly, the metal ballast weight is bonded to the center of the rear case- helping to dampen it as well. You want the case to be "dead" acoustically - and that's what I've done. Resulting SSB audio sounds smooth and more articulated. The DSP doesn't have to encode and then remove excess bass information -wasting precious extra bits on audio which doesn't add to the intelligability of the signal. The slight boost in level is a welcome thing as well. Now, the compressor is an option...not a requirement. In any case, thanks again...to all who have trusted my analysis on this. It's not a miracle fix, bit it brings us to a place audio performance-wise where we can again focus on enjoying the rigs other excellent features. 73's Bob- AB5N ======================================================================== HM-151 microphone upgrade coming HM-151 Mic Upgrade Works great1 Posted by: "Charles Scott" cscott@gaslightmedia.com n8dnx Date: Sun Sep 17, 2006 7:46 am (PDT) Dick: I've had a 154T on my IC-7000 in the car for some time now. It's connected to the front panel jack and the original 151 is connected to the rear mic jack and routed to the back seat where I have the video from the 7000 displayed on the entertainment system. When I fist received my 7000, I dissasembled the 151 and carefully aligned the mic element with the hole in the case and opened up the hole slightly. That's the only mod done to the 151. The audio from the 151 is a bit brighter than the 154T now and everyone says it sound good. I'm thinking of takeing a close look at the 154T to see if I needs some similar adjustment. Over all, however, nobody complains about my audio quality right now on the 154T, but then nobody mentions how good it sounds either. I think I'll bring it in this morning and look at how the mic is mounted to see if it needs some work. Will report back later. Chuck - N8DNX On Sat, 16 Sep 2006, Richard Pongratz wrote: > According to several sites the 154T is out there and available. It is > listed as a replacement mike for most of the Icom rigs. Memphis Amateur > Electronics shows it as a replacement for the 703 Plus and the 703MKII. > Yup--the 703MKII. I know nothing of the 703MKII, but assume they mean > the 706MKII. Several sites list it as a replacement for the IC7000, but > I can't find it on their sites or any information about it. I can't > find it on the Icom web site either. I wonder if it has better audio. > Maybe these modifications are already taken care of. Anybody have one? > > 73's, Dick, K5SHT ======================================================================== HM-151 Posted by: "Phil LaMarche" plamarc1@tampabay.rr.com w9dvm Date: Sun Sep 17, 2006 3:00 pm (PDT) Received my modified mike back from Bob Nagy and what a difference. When I used it before, everyone on the freq I occupy said I just sounded OK. Now they made comments without even knowing what I did. Raved about the audio. Why would you want to buy another hand microphone when for 30 bucks this one can be made to sound really good. Phil Philip LaMarche LaMarche Enterprises, Inc. ======================================================================== HM-151 Posted by: "steeledg8upo" steeled@iron.demon.co.uk steeledg8upo Date: Mon Sep 18, 2006 2:20 am (PDT) --- In ic7000@yahoogroups.com, "pe1jlj" wrote: --- In ic7000@yahoogroups.com, "Richard Pongratz" wrote: Who is doing the modifications again? Could someone email me who we send the mic off to and how long it takes? the info is in the links section. however, I still think it's difficult to justify to do the mod as there are no comparision files available yet. Other mods available too; change one condensator and add some foam. ----------------------------------------------------------------------- I have been reading the many posts about the HM-151 and I think there could be a manufacturing issue. I had the feeling mine had low audio level. So I took it apart and looked though the mic hole and found that the hole in the keyboard membrane did not line up with the hole in the case. There was only a very small hole visible. I then made the hole bigger in the keyboard membrane and put the thing back together. What a difference it made. The highs we comming through better. I also found that it is better to put the mic at the side of your mouth and talk to it side on. When you do this it stops the popping sounds on "P"s. (This is important to me as I have a P in my call :) ) However I still think the mic level is low on FM. I checked and found the audio level appears to be below the 1750 Hz tone burst. This is incorrect the modulation for voice should be louder than the tone burst. The upshot of all this is that the HM-151 is designed like a hand-held - ie. the front is taken up with the keyboard. They should have put the keyboard on the back and left the front for the sound to get in properly. Just my thoughts. 73 Dave G8UPO ======================================================================== Basic Help for TX Audio on the IC-7000 Posted by: "Stephen Prior" sjp@sjprior.fsnet.co.uk g4sjp Date: Sun Sep 24, 2006 9:32 am (PDT) As supplied, the audio quality with my voice and the stock microphone was awful- I have a fairly bassy voice to start with. What completely revolutionised my audio was removing the existing chip capacitor C30 (0.1 microfarads) and replacing it by 0.2 microfarads. [[ See note below ]] In addition I filled the voids behind the mic element with styrofoam pieces. In a direct comparison, listening on the in-built monitor I am hard pushed to tell the difference between the 151 and my SM-20 ­ in fact I am thinking that I will put the SM-20 on ebay! Unfortunately I had to buy the OPC adaptor to perform the test, so that will be up for grabs too! The modification, courtesy of K6HTM is in the files section. It took me no time at all to do and is essentially a zero cost, minimally invasive operation! Your mileage may vary! 73 Stephen G4SJP ----------------------------------------------------------------------------- On 24/9/06 03:04, "dietmarfichter" wrote: So basically to solve the so called bad audio problem of the IC-7000 stock mic, the element needs to be replace with one that produces a higher level of audio output? The problem appears to be level problem rather then a frequency response problem, right. Dietmar> VE3CG --- In ic7000@yahoogroups.com , "ab2et" wrote: I will agree with your statement that the microphone pre-amp circuit is closer to older none "Pro" Icom models and that we may have to deal with that situation all over again. Yes I know quite well that it is a "inexpensive" microphone but it is the only one that has all of the control features built in that I use while I am mobile The interesting find that I ran into with my own unit was that when I replaced the "stock" Icom element with a salvaged Cell phone (Nokia) single hole element my audio went way up and it was clear and crisp not distorted and mushy on FM (I have a normal voice, not bassy or high pitched). For testing purposes I installed a mini Teflon insulated socket on the mike PC board so as to keep things nice and tidy and decided to test the elements externally using the same voltage/current setup that Icom has in the hand mike (got the info from the schematic). The results indicate that some elements, I tested 5 different electrets' that I have in the shack have built in amplifiers (3) and the stock Icom model is not one of them nor is the R*t Shack unit. The Salvaged Nokia element has a built in pre-amp and thus the better higher level audio with no need to run "compression" on SSB. I decided to build a small single stage pre-amp and match the level to the Nokia (dead bug style and then heat shrinked) I hooked it to a extra H-5 element and it works quite well thank you very much but no space for the element. At this point I see that all one needs to do is get a electret element that has a built in high level (some elements can be adjusted by supply voltage) and substitute the stock element to solve most of the 7k audio hassle, or splurge the $30 and have it done by one of the board members who first did it for his radio and now offers this to others. 73's AB2ET ======================================================================== Basic Help for TX Audio on the IC-7000 Posted by: "Stephen Prior" sjp@sjprior.fsnet.co.uk g4sjp Date: Sun Sep 24, 2006 9:59 am (PDT) Before someone else spots the error below, I meant that I replaced a 1uF capacitor with 0.2uF, not as I wrote! Stephen ======================================================================== Basic Help for TX Audio on the IC-7000 Posted by: "cpcohen1945" cpcohen1945@yahoo.com cpcohen1945 Date: Sun Sep 24, 2006 5:33 pm (PDT) FWIW -- On the IC-706, there's a "carrier offset" setting buried in the menu system. It lets you tune the carrier insertion frequency across the fixed-width (2.4 kHz) "transmit" IF filter. So you can change your SSB output to include audio frequencies of 0.2 - 2.6 kHz (lots of lows), or 0.5 - 2.9 kHz (not much lows). Its effect is similar to adjusting the low-frequency cutoff of the mic. This makes a significant difference in the tonal balance of the SSB signal. According to Bob Heil (it's mentioned on his website), it's quite important in getting "best quality" audio. And my listeners have helped me adjust it for "maximum punch". A similar adjustment is built into the Yaesu FT-817. Has this "carrier offset" capability been built into the IC-7000? Or has it been lost in the transition to a DSP-based radio? Charles Cohen VA7CPC PS -- Sorry if this has been discussed. I've been going through the "mic mods" thread, and nobody mentioned it as a possible adjustment. ======================================================================== Heil Mirophone offering for the IC-7000 Posted by: "Richard Stern" imaglitch@yahoo.com imaglitch Date: Sun Sep 24, 2006 10:18 am (PDT) I'm using the Heil HM-iC with my IC-7000 with good results. Make sure the mic switch is on the WIDE position(not NARROW.. Heil told me not to use the narrow position at all. It's for close-up work when there is alot of background noise). SO, my setting are withe GAIN = 42 to 48 and COMPRESSION = 1 or 2. I QSO'd with a fellow ham at 7.275Mhz for about an hour. He also had a IC-7000(I don't recall his MIC). The band conditions weren't that great and he said I was doing a solid S9 with a good well rounded tone quality. All other settings are default. He also said there was a little fussy sound at the peaks of my voice pattern. I have an oscillating fan behind my desk that keeps air circulating behind all my gear. I believe that is what is causing that condition. If you can get a HAM kind enough to give you an honest signal report and spend some time going through your configuration. You probably could clear up your problem. Thanks for reading this ! de NW3N Richard --- David HOLMAN wrote: > I have an HM-iC which seems to work well with the > 7000 > I would be interested to know if there any specific > settings I should make > on the 7000 to get the best from the mic ======================================================================== ======================================================================== ======================================================================== ======================================================================== ======================================================================== ======================================================================== ======================================================================== ======================================================================== ======================================================================== ======================================================================== ======================================================================== ======================================================================== ======================================================================== ======================================================================== ======================================================================== ======================================================================== ======================================================================== ======================================================================== ======================================================================== ======================================================================== ======================================================================== ======================================================================== ======================================================================== ======================================================================== ======================================================================== ======================================================================== ========================================================================