eHam

eHam Forums => Boat Anchors => Topic started by: GM8UPI on September 06, 2013, 10:55:25 AM



Title: TS-830S Mic Gain
Post by: GM8UPI on September 06, 2013, 10:55:25 AM
Hi folks. My newly acquired TS-830S seems in v good condition. RX works great on all bands. TX also seems good giving 100w+ on all bands, key down, but I note that on max carrier drive, the ALC only reaches 50% of meter scale on 10mtrs. (Goes over full ALC scale on all other bands.) Note key down for a couple of secs only!
No real problem then? Perhaps need to change driver tube in near future.
However my main concern/problem is that when using SSB with MC-50 desk mike, I require to speak-up the mike closer than I would really like (2inches as opposed to around 6-8inches) with mic gain at max. Doing this does give me a good 100w pep.
Will changing to a "good/new" driver tube improve this situation?
Apart from this I am getting excellent audio quality reports.
Any advice on this would be appreciated.
Love this old rig!!!
73
Dave


Title: RE: TS-830S Mic Gain
Post by: KD2DYY on September 06, 2013, 12:01:01 PM
Dave................... Don't you just love that 830s????? If I could eat a radio it would be that one..... Wonderful!
Look at Ken's web site.......K4EAA.com..... Pay particular attention to the tune up procedure that he details.....Heck , look at his whole site.... He has most ,if not all the answers for these fine radios....
I do agree with you that the driver seems to be getting a little " soft"but let Ken be the educated source of knowledge on your issue..... he is ,truly, the expert.....
There is a Yahoo, "Kenwood" user group that is very knowledgeable as well. I am a member of that group but I warn you that they are VERY technical in thier diagnose and repair procedures......Hold your breath when you post a question and be prepared for shoot back for more info.... They do NOT mess around.... That is a good thing. you want answers, not blase' opinions.
Good luck on finding the answer Dave.... Feel comfortable that thier is a lot of help to any repair/operational issues with these fine old Kenwoods. I'm a believer..... You are ,well, on your way to be one as well.
Get back to me for the particulars on the Yahoo user group if you are interested..... Our Eham.net is great as well.

                                                                                                                                  Best of 73's Dave
                                                                                                                            Meet you on 17m or 40m
                                                                                                                                    Mike KD2DYY


Title: RE: TS-830S Mic Gain
Post by: GM8UPI on September 07, 2013, 12:11:23 AM
Hi Mike. Thanks for coming back on this. Yes, I have been studying Ken's web site. I have used his services when refurbishing my TS-520, a lovely classic and the original "best of bunch" in my opinion, of the first Hybrids! Lovely rig, and I will never part with it until SK arrives! LOL.....
Certainly would be interested in the Kenwood Group link, if you can give me a stear on this.
Maybe catch you on air some time during this coming winter. As my QRZ page indicates I spend most of my time these days here on the Isle of Skye, Scottish Western Islands. Lovely and remote but being a "towny" by birth, I am now loving the isolation!
73
Dave


Title: RE: TS-830S Mic Gain
Post by: G3RZP on September 07, 2013, 01:11:16 AM
Dave,

Bear in mind that you have a rig MUCH cleaner in terms of high order IMD product than anything available these days. You might need new PA tubes as well, though.

73

Peter G3RZP


Title: RE: TS-830S Mic Gain
Post by: GM8UPI on September 07, 2013, 01:36:44 AM
Hi Pete. I have plenty of good spare 6146B's and driver valves, so no problem to revalve the rig.
Still wondering if the need to have mic gain fully up is norm on using these hybrids, and having to talk close to mic for correct SSB drive level. ie mid ALC scale.  Both 520 and 830 are identical in this respect, using same MC-50 mic !
Would have thought that the design would allow normal desk mic distance, ie 6-8ins, to be around 60 - 80% of mic gain setting, for full drive without overdriving anything.
Investigation continues.................
Regards
73
Dave


Title: RE: TS-830S Mic Gain
Post by: W8AAZ on September 07, 2013, 06:18:20 AM
"Using the same mic".  I suppose that might make me wonder if there is some issue with the microphone itself with both radios behaving the same, unless you have found some other explanation, such as other's radios seem to have the same sort of problem. However I suspect alot of the older radios have a reduction in transmit efficiency at the very highest bands.  My experience is that only the more modern broadband solid state radios tend to be totally consistent or nearly so, in output.  I don't believe that my old FT radio can put out as much power at 10 as it does at 75 metres, regardless of how fresh the VED's are. (Eimac now refers to tubes/valves as "vacuum electron devices" ::)). 


Title: RE: TS-830S Mic Gain
Post by: GM8UPI on September 07, 2013, 08:11:39 AM
Hi, thanks for responding. Not really concerned about power falling off slightly on 10. I think all tube rigs tend to do this as tubes age.
My main concern is in the use of desk mic and having to use this close-up and at full mic gain setting to produce approx 100W PEP and get the ALC registering by a small amount, powered into DL with a good, recently calibrated peak meter. (And yes, before anyone comments, I know all about how difficult it is to measure PEP on these meters!!)
The bottom line is I get great audio reports using the mic close-up, and I am looking to get same while talking 6-8inches away, and preferably, not with mic gain fully up !!
I've no reason to suspect the MC-50 and I have also tried a Shure 414B fist mic with same results.
The mic Amp circuits (3 transistors before 1st mixer) are similar but not totally identical in the 520 and 830. BTW the VOX works just fine, which tales audio signal after 1st mic amp transistor, which would indicate this stage is OK.
Will try replacing driver tube, then perhaps finals, and report back. (Neutalization being carried out of course, for finals !!!)

73


Dave


Title: RE: TS-830S Mic Gain
Post by: KD2DYY on September 07, 2013, 05:52:17 PM
Dave (GM8UPI) Here is the Yahoo user group that you can join... You have to ask for permission to join but you should have no problems in that regard....

http://groups.yahoo.com/group/ts-520_820_530_830_/

Join thier site and , like I said, watch out, they WILL tear into your issues with a vengeance...
Just give then a detailed list of what you have done so far, they will dig in....
Offer to help anther member when it is YOUR chance to do so.
 This is one more example of kindred spirits helping out  one another in a wonderful hobby.
Best of luck Dave and I hope to "work" you on the bands in near future....

                                                                                                                  73's Dave.
                                                                                                                Mike KD2DYY


Title: RE: TS-830S Mic Gain
Post by: K8AXW on September 07, 2013, 08:06:21 PM
Dave:  The TS-830S is my main transceiver and has been for over 30 years. 

If you're getting 100+ watts out of it the driver and final tubes are OK. 

Normally, (which is always) my MIC control is at 5 (12 o'clock)  and the CAR control is at 2 (9 o'clock)

I use a Heil HC-4 mic element and it is within 3" of my mouth when I talk in a normal voice.

I also have the Kenwood MC-35S hand mic which is also a close talking mike....probably within an inch or two of my mouth.  Both give full output on voice peaks.

Does your mic have a Noise Cancelling and Normal switch on it?  If it's set to Noise Cancelling, then you will need to speak closer to the mic.

The very few times I've tried a desk mic I've found that I needed to be within just a few inches of the mic for full output.  This is why I prefer the boom-mic with headphones and a hand mic. I like to be able to move my head around while operating.... like to see the computer screen or do my logging, etc. 



Title: RE: TS-830S Mic Gain
Post by: GM8UPI on September 08, 2013, 02:32:14 AM
The Kenwood MC-50 Desk mic, is the original mic designed for use with the TS-520, TS-830 series rigs. It has both a high and low impedance capability, with high being selected for the old hybrids. No fancy electronics etc, just a straight forward dynamic element and a built in transformer, for high, low impedance selection, made by rotating the rear connector of the stick mic by 90deg.
Difficult to see how it can be faulty, audio reports are great. Basically these mics are just like a mini speaker, with drive coil and permanent magnet. Front of mic is clean, with no obstructions etc.
Unfortunately I am "up country" for the next month or two, so do not have access to my test gear, scopes, RFVM, etc.
First move today will be to change driver tube, and see how that impacts on mic gain settings etc.
73
Dave


Title: RE: TS-830S Mic Gain
Post by: N8CBX on September 08, 2013, 07:00:29 AM
I use the Shure 444 on all my Kenwood hybrids, please try one. I put all my MC50s back in the box. They have a little more gain than the MC50s
Jan N8CBX
73


Title: RE: TS-830S Mic Gain
Post by: GM8UPI on September 08, 2013, 04:30:06 PM
OK. Changed driver tube. Tried several. All worked fine, with only a v small variation in car drive setting, to produce same level of ALC. at 100w key down. Left the one in with the lowest car level setting for output. (Choice was really marginal !!)
OK. So replaced both final tubes. Quiescent current set for 60mA, only slight adjustment needed. Neutralized as per manual, Again only slight adjustment required.
Rig performing fine on all bands, with 100W+ all bands, incl 10m.
However no detectable change in SSB mic levels. IE having to speak close to mic with full mic gain set, to move the ALC to half scale !!!
Any other ideas folks ???
73
Dave





Title: RE: TS-830S Mic Gain
Post by: KD2DYY on September 09, 2013, 03:47:01 PM
Dave.................. time to get into that user group I told you about at Yahoo.( Reference my previous reply....) They DO have the expertise to help you find out the root cause of your low mic input......
I run my gain at approx 12 oclock and if I do use processor that control is set no higher than 1030.....I had my signal looked at by another Amateur that had a "'Flex7000" and he said it was just right and well withing the 3khz allowance.( about 2.3 Khz).
Now this is with Dynamic mics.... My radio did come with a Shure 444 desk mic and I have had reports that it sounded very good with that mic installed. Too bad, I like hand held PTT mics....Oh well.
Good luck Dave....... Hope you find out the solution soon.
 Fine radio you have, there. Please do NOT give up......

                                                                                                                              Mike
                                                                                                                           KD2DYY


Title: RE: TS-830S Mic Gain
Post by: GM8UPI on September 10, 2013, 09:07:21 AM
OK Mike. Have joined "Yahoo Group"!!!!
Just plucking up courage to make a posting topic :-\ :-\
73
Dave


Title: RE: TS-830S Mic Gain
Post by: K9TW on September 10, 2013, 05:18:10 PM
Dave:

I agree with Jan N8CBX. I have several MC-50 and MC-60 mics and it is normal to have to talk up the MC-50 mic. People like its bass response, but if you run barefoot the Shure 444D is the mic I prefer. It is much hotter than the MC-50. Its frequency response has more communications presence so you wont get those glowing Kenwood audio reports, but you will make copy of your signal better when conditions are less than ideal or chasing DX.  I typically can run the mic gain no greater than 1100 to 1200 using the 444D and have ALC peaks about mid-scale of the black rectangular range while speaking at normal levels.

That being said you really dont know if your ALC indication is calibrated or not if the rig has passed thru other hands. The TS830 has two different ALC meter driver circuits and it requires calibrating one for S-meter function and the other for modulating the rig. If you have a Service Manual look at Step 31. It requires an accurate Audio Generator (need accurate 5mv and 10mv levels @ 1500hz) and an external wattmeter to perform this step. If you have this test gear suggest you check the cal of your ALC meter circuit. Pretty common to find them out of adjustment.

Terry K9TW



Title: RE: TS-830S Mic Gain
Post by: GM8UPI on September 11, 2013, 12:40:53 AM
Hi Terry. Well the consensus of opinion seems to be the rig is working just fine, in regard to TX output and SSB modulation with the MC-50 mic.
My next move is to try my Behringer mic amp/mixer in line with the MC-50. As this is really designed for low impedance mics, with low imp output, I am sure this will have a fairly drastic impact on the overall audio response. However, if it allows me to use the desk mic at a more comfortable distance, without overdriving the mic audio chain, then I can live with that, albeit without getting my usual "great Kenwood audio" reports !!!!
Watch this space !
73
Dave


Title: RE: TS-830S Mic Gain
Post by: KD2DYY on September 11, 2013, 12:45:39 PM
Very good Dave....... That Yahoo group will tear into your issue......Watch out....... LOL!   Not to worry. They may come across rather "strong" but they are trying  to thread down to the root problem. They WILL ask what kind of test gear you possess.Again, that will help them know what you can and cannot check out with the gear at your disposal. I would be great if it is just a simple calibration issue with the ALC meter read (as per previous posting)...
Good luck,again Dave....... Just believe in the old girl and she will settle down. (I AM speaking about your 830s of course .LOL)

                                                                                                                  very best of 73's.
                                                                                                                    Mike KD2DYY
                 


Title: RE: TS-830S Mic Gain
Post by: GM8UPI on September 11, 2013, 11:41:02 PM
OK Mike. Just made my first post to group ;D
Let's see what the "experts" say....
73
Dave


Title: RE: TS-830S Mic Gain
Post by: GM8UPI on September 16, 2013, 02:23:12 AM
OK. Consensus from "experts" is that my TS-830S, together with my MC-50 mic, is 100% ok. It seems that this mic is not ideal for use at distances greater than 4ins from the face !! Using the rigs built in processor, set at around 8 - 10dB compression, will overcome the mic distance problem to some extent, without any great deterioration in audio quality.
Suggestions varied from "get a different mic" to "build a pre-amp into the base of mic". I am considering the latter option.
Thanks to all who contributed to this post.

Regards
73

Dave


Title: RE: TS-830S Mic Gain
Post by: KD2DYY on September 25, 2013, 08:13:53 PM
Good news Dave...... I oNLY use PTT hand mics.... I don't like trying to keep my mouth close to desk mics.... Only problem I have is keeping the push button down while I take a long turn in the QSO. LOL! Guess I'll have to look into a lock "on" for the PTT button. I'm sure they are available...
Oh, before I forget.... Try to locate a fellow Amateur that has a "Flex" radio and can analyze your audio on the spectrum they have at thier disposal... I have a good friend over here in the Syracuse NY area that has one and he was kind enough to lead me in the proper setting of the "gain" and "processor"  control that made it spot on..... I now know exactly where the controls should be set... Keep in mind that a change of mics will require a new analysis...
Those "Flex" radios are wonderful but I don't have the $$$$ to ,even, think about that step up.... I love the old Hybrids so no heavy lusting at this point. LOL!
Hope to meet you on the air in near future. I love 17M .... 40M has always been my favorite but the dx on 17 is amazing..
I can get on 20m and 15M as well. All with separate dipoles... I love to throw wires over the house. (XYL does NOT)

                                                                                                                        Best of 73's Dave,
                                                                                                                         Mike-KD2DYY


Title: RE: TS-830S Mic Gain
Post by: GM8UPI on September 26, 2013, 09:49:18 AM
Hi Mike. OK on "Flex" analysis. I do have a very good friend with the set-up required, about 35mls to the North of me, on another Scottish island. He has in the past played back my transmissions, usually on 40mtrs, when short skip was good.
Still to do some experiments ref the MC-50 and TS830S set-up, starting with using an external mic pre-amp (voltage gain around x3 or x4 but variable) between rig and mic. I think all I am really looking for is a bit of headroom in regard to mic gain setting while talking at 8 - 10ins from mic. I can 'scope audio sig levels, to ensure no clipping/overdriving into rig audio stages.
Depending on success of these tests, I may build a pre-amp into the base of mic stand. I have already designed this and have all components required. May give the mic a small boost at the higher frequencies 1 - 2.5 KHz with my design, as reports so far seem to indicate this may improve the already good reports I get, albeit close talking the mic!
Maybe catch you on 17mtrs some time. Perhaps we can make a sked! I will be more active during the coming winter months, but only running around 100w to a big doublet.

Regards
73
Dave de GM8UPI/P
(Operating most of time from Scottish island of Skye.)


Title: RE: TS-830S Mic Gain
Post by: KD2DYY on September 26, 2013, 05:43:11 PM
More good news Dave...... You seem to have the answers you need. You have to get into the PTT mics..... LOL! No problem with pre amps or any of that..... Oh well, you KNOW what you like......
ok on 17M.. Love that band and was just listening to it. No skip tonight.  It is 2030 in Syracuse NY. 130 am your time. Bet you are sleeping...
If you do get on 17M what frequency do you like and your most likely time.... ? If my little 830s with 100 watts won't make the trip.. I can fire up the old SB200... That gives my 650 plus.
Ok, I will be looking for you...... Hang in there Dave...... Best is yet to come.

                                                                                                                    Best of 73's
                                                                                                                   Your friend
                                                                                                                    Mike-KD2DYY


Title: RE: TS-830S Mic Gain
Post by: G4FUT on November 05, 2013, 04:43:39 AM
Regarding using the processor on the Kenwoods; I have 4 of the beauties here, 520; 530; and 2 - 830s. I've been using them since I was licenced in 1974.  I ALWAYS use the processor, having been old by many OPs that it greatly improves the readability of the signal.  However that is not to say that the signal was not readable in the first place.


Title: RE: TS-830S Mic Gain
Post by: K7WXK on November 24, 2013, 07:43:58 AM
Dave,

Glad to hear your rig is clean and the problem is likely in the desk mic.  At the risk of muddying the waters, I have a Yaesu FT-990 and the factory MD-1 desk mic, and I must admit it doesn't sound nearly as good as when I use it with my old D-104 (high impedance) mic that I bought new back in the '60's.  Although I would very much like for the factory mic to perform well, it is only average at best.  I mostly use the D-104 with my "boat anchor" rigs and it consistently out-drives all the other classic (high impedance) Electro-voice mics in the shack.  I can't explain it, but it just works very well.

What I am trying to say is the venerable D-104 is a great performer in a variety of high and even low impedance requirements with lots of punch in either case.  They are inexpensive and they feel good in the hand.  I would think the 830 would be a great candidate for this mic.  JMHO.  Good luck.

Marc


Title: RE: TS-830S Mic Gain
Post by: GM8UPI on November 24, 2013, 11:31:06 AM
Hi Marc. ok on your mic experiences. Still experimenting here. Certainly on my TR-830S, without using the inbuilt processor, my MC-50 mic lacks the level of drive that I want, when speaking 8 - 10ins from the element. Not really a big problem as, others have stated, this rig / mic combination works really well, with the processor on at approx. 10dB compression. By others experience, it seems that the MC-50 is really a "close speaking" mic, presumably due to low sensitivity (ie Output v Sound Pressure).
I have several other mics, although these are all lowish impedance. I will be experimenting with these, combined with a mic imp adapter, and a preamp.
I did have a Shure 444 mic some years, but I regrettably gave it away without realising it's potential >:( >:(
73
Dave