Re: [Elecraft] D-104 Element Replacement
Do any of the mics you mentioned have frequency response curves similar to high articulation mics like the original Astatic D-104? or the vintage Heil HC-4/5 ??? _ Howdy! Good question, Tony. Yes, some electret capsules and maybe fewer dynamic cartridges have the frequency response curve you seek, although it is somewhat difficult to separate them from the larger herd. One must research each response curve graph or learn of one from a vendor or mic expert to narrow the field to what you seek. A lot of microphones have a response curve and tone pattern like the famous Shure SM58, about the most popular vocal mic in the past 40 years. One exception is the AudioTechnica MB1000L, from the AT Midnight Blues collection, which has the thinner, more articulate sound you mention. You just have to do you homework to find one like that. Some guys use particular capacitors to modify the tone of a particular microphone, thinning or thickening the tone by rolling off high or low frequencies. For example, in a related application, Leo Fender used to ad a .1 uf capacitor to roll off the bright, almost harsh tone of a Fender Telecaster electric guitar. Modern players use different capacitor values because they feel Leo's pick makes bass tones sound thick, dull and "muddy." The point is, you might mod a particular microphone to achieve the frequency response curve and "tone" you desire. Therefore, if you cannot find a particular capsule or cartridge that suits your taste, you might modify one to complete the task. OR - you might employ a microphone pre-amplifier and/or outboard equalizer or mixer with EQ controls to achieve the desired result. As another op mentioned yesterday, HEIL stopped selling multiple cartridges, as so many modern transceivers have adjustable transmit EQ to achieve the desired result. Someone mentioned the $20 BM-800 electret condenser microphone which looks like a larger, more robust large diaphragm studio microphone, but has a much smaller, less capable condenser capsule. And yet it DOES sound OK, PROVIDED you use it carefully and speak close to its sweet spot (best speaking distance for best S/N etc. ) - but I find it is comparatively noisy compared to a) higher quality, slightly more expensive larger diaphragm condenser microphones - e.g., the Behringer B1, and compared to 2) a performance style dynamic microphone, such as the Sennheiser e835. Bob Heil correctly explains why he does not favor condenser microphones - they tend to be much more sensitive and capture more ambient noise in the shack, as they say in the business, that type of capsule can "pick up a gnat's fart across the room" (sorry for being crude, but that IS what THEY say!) A close-talked performance type dynamic cartridge captures less ambient noise when transmitting. They also tend to have more narrow response curves which, as another op suggested, may be better suited to producing communications audio. So, you pays your money and you takes your chances. Do due diligence and find the mic that suits your voice and objectives best. Good luck. Just a few ideas. Good Luck. K8JHR __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
[Elecraft] D-104 Mic Element Replacement
If you have a working, unamplified D-104, the solution to this is quite simple. Back in the 1990s, my transceiver was a TS-830S. I had a pre-citizens band D-104. These classic microphones were much heavier than the later ones and had a stamped serial number plate riveted to the head. The output of these microphones was very high and, when connected to an input with an impedance of a few tens of thousands of ohms, the frequency response was very strident. The Astatic data sheet for the D-104 contained a graph, with curves, which showed how a lower impedance load suppressed the mid range and bass response. Inside the base of the push to talk stand, I placed a 787 kilohm,, quarter-watt, metal film resistor in series with the hot side of crystal cartrige output. The D-104 no longer sounded shrill. The response was silky smooth, as determined by transmitting into a dummy load and recording the audio from a second transceiver. As a bonus, I could then run my mic gain at eleven o clock, rather than nine o clock. This made it much easier to set the mic gain properly, as the control was not so touchy. I was actively DXing, back then, and the slightly modified D-104 did a great job of breaking pileups. I was often complimented on my audio and often asked what microphone I was using. Gary, K0CX “Most D-104 mikes are not suited for use with today's radios.? The original D-104 was designed to work into a load impedance of 4 meg-ohms or higher.? Today's radios microphone input is about 50k ohms or so.?? The result is then excessive load on the D-104 element.? This is the major cause of frequency response issues. Bob McGraw” -- This email has been checked for viruses by AVG. https://www.avg.com __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] D-104 Mic Element Replacement
I remember the D104's from my early years in Ham radio. I never had a mic for my DX35 in the late 1950's and acquired a carbon mic with the old AN-ARC-1 VHF AM radio I bought for 2m AM as a Tech. I upgraded to a Johnson 6N2 after college so bought a new Electro-voice mic that had cardiode pattern for noise reduction. It was shaped like a long silver tube and I got a desk stand for it. It was a broadcast mic so made fine quality AM on 2m with my plate modulated 5894 at 150w. All that gear is gone, now. Most of my station is now Elecraft. 73, Ed - KL7UW __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] D-104 Element Replacement
I believe all electrets will have high freq response well beyond 15K... way past bell labs' 300-3000 cps voice response. And it looks like all the most inexpensive mics do use the electret elements. They might not have a lot of bottom end... but "we" don't need that anyway . Then add in that the K3 & K4 have an equalizer..and most anything resembling a microphone could be made to sound ok. I see that the "fancy" electret with a boom and accessories has hit a new low price. 19.98 SHIPPED NEWEGG is selling one of a million versions of the BM-800. Google bm-800 and loo see. It does plug into the back of a k3/k4 with no special cables needed. I bought one a few years ago ( 29$ amazon) to see how bad it was ...and surprised it works fine. bill On 2/23/2022 9:48 PM, Tony wrote: On 2/23/2022 5:54 PM, JR wrote: I am often amazed how little some hams know about microphones. You can purchase any number of compatible dynamic microphone cartridges, or electret condenser capsules, and fit them into a D-104 head shell. JR: Do any of the mics you mentioned have frequency response curves similar to high articulation mics like the original Astatic D-104? or the vintage Heil HC-4/5 (see graph below). I found that most "generic" mics have way too much low-end response with little top-end so they sound very muddy and not very articulate. Not the best choice for entry level and older rigs that do not offer TX-EQ. Tony -K2MO __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to n...@arrl.net __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] D-104 Element Replacement
On 2/23/2022 5:54 PM, JR wrote: I am often amazed how little some hams know about microphones. You can purchase any number of compatible dynamic microphone cartridges, or electret condenser capsules, and fit them into a D-104 head shell. JR: Do any of the mics you mentioned have frequency response curves similar to high articulation mics like the original Astatic D-104? or the vintage Heil HC-4/5 (see graph below). I found that most "generic" mics have way too much low-end response with little top-end so they sound very muddy and not very articulate. Not the best choice for entry level and older rigs that do not offer TX-EQ. Tony -K2MO __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
[Elecraft] D-104 Element Replacement
I am often amazed how little some hams know about microphones. You can purchase any number of compatible dynamic microphone cartridges, or electret condenser capsules, and fit them into a D-104 head shell. I buy a number of excellent dynamic replacement cartridges on eBay for less than $10, and purchase suitable electret condenser capsules for as low as 10 for $1, including shipping in some cases! Research and shop around and you will find all sorts of inexpensive replacement elements that sound great. I built a test bed of several microphones and nobody has ever correctly identified which element is which - including the HEIL PR-20 I included as a "control" sample. I once purchased an old Shure Unidyne 55C "Elvis Style" microphone and installed a $7 replacement cartridge after super cleaning and polishing the original zinc-alloy head. Looks good - sounds good - total cost under $20 including cleaning materials. Point is ... you can easily upgrade an old mic on the cheap without sacrificing sound quality. I cannot bring myself to even consider what W2ENY sells after comparing his stuff to what appear to be comparable and possibly the same items on eBay.com and Aliexpress.com. For example, compare his $70 desk boom mic with this one on Aliexpress, and reach your own conclusion. I acknowledge he solders a Foster connector on it, but that is much more than I expect to pay for a quick solder job and a $2 plug and a bit of shrink tube. https://tinyurl.com/y2n7ussm https://w2eny.com/deskmic/ Of course, this is just my "take" (opinion) and I may be way off base. Everyone should do diligence and draw his own conclusions. JHR __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
[Elecraft] D-104 Mic Element Replacement
Most D-104 mikes are not suited for use with today's radios. The
original D-104 was designed to work into a load impedance of 4 meg-ohms
or higher. Today's radios microphone input is about 50k ohms or so.
The result is then excessive load on the D-104 element. This is the
major cause of frequency response issues.
The D-104 with the TG stand {amplified mike stand} uses the FET device
as a buffer, thus it is providing a very high impedance for the mike
element and adequate gain to drive a 50k ohm or lower microphone input.
As to replacing the D-104 element, if yours has output, likely it is OK
and is suffering from the issue of improper load on the element.
Remember, this mike was designed to operate with tube type microphone
amplifiers, having an input impedance of several meg-ohms.
The D-104 on my TUG8 stand has the original Rochelle salt element and
the FET amplifier in the base. It sounds great on any of my radios. My
comment is that one should use the mike such that moisture or spittal
from the mouth does not accumulate on the mike face and element. Also
don't leave it in a position where the equipment will heat the D-104
above room temperature and surely left in the direct sun.
I frequently hear hams talking about using a D-104 with a Heil
element. Fact is, it no longer is a D-104, it is a Heil HC-4 or HC-5
or whatever.
73
Bob, K4TAX
On 2/23/2022 1:57 PM, elecraft-requ...@mailman.qth.net wrote:
Message: 2
Date: Tue, 22 Feb 2022 17:35:58 -0500
From: Dean Adinolfi
To:elecraft@mailman.qth.net
Subject: Re: [Elecraft] D-104 Mic Element Replacement
Message-ID:
Content-Type: text/plain; charset="UTF-8"
W2ENY element works great.
https://www.w2eny.com/
Dean, KD3ANX
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[Elecraft] D-104 Mic Element Replacement
Thanks for the references. Some of the elements from the harmonica place are interesting, but expensive. A good source, if they are OK. Emboldened by D-104 Element Repair - Mike Harrison (smugmug.com) I tore into one and found the diaphragm glue gone and the linkage between the diaphragm and element loose on both ends. The repair is easy and preliminary indications are it's working OK. I don't know if it's a crystal or ceramic element, but it's hot, so I expect ceramic. I'd bet quite a few cartridges have been replaced because of these problems! Wilson __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
[Elecraft] D-104 Element Replacement
No actual replacement found so far, but several nice dynamic/electret conversions. Encouraged by this posting on QRZ, D-104 Element Repair - Mike Harrison (smugmug.com), I decided there was nothing to lose by looking inside. It's actually no problem at all and I found multiple problems: linkage between diaphragm and element loose at both ends, diaphragm perimeter glue completely gone, wooly stuff between screen and diaphragm completely gone. I did a very quick repair, attaching the linkage to the element with beeswax and the diaphragm to the linkage with rubber cement. Preliminary testing on the air indicates the response is very similar to that of a believed good unit, so I'm declaring conditional victory until better tests are available. SO, the moral; You may not need an element at all, if you are willing to fool around a while and repair what's wrong! Not like I had nothing to do, but it's nice to get to the bottom of something. WL __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] D-104 Mic Element Replacement
Moreover, Bob Heil retired and sold the company earlier this month. https://heilsound.com/press/heil-sound-announces-new-owners/ 73, Kent K9ZTV > On Feb 23, 2022, at 9:57 AM, Bill Coleman wrote: > > Heil Sound stopped selling HC4 and HC5 mike elements many years ago. (10 > years ago?) > > I think part of the rationale was that modern rigs have built-in equalizers > that eliminated the need for a crystal microphone with a tailored response. >> > __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] D-104 Mic Element Replacement
Heil Sound stopped selling HC4 and HC5 mike elements many years ago. (10 years ago?) I think part of the rationale was that modern rigs have built-in equalizers that eliminated the need for a crystal microphone with a tailored response. > On Feb 22, 2022, at 9:03 PM, Don Wilhelm wrote: > > I have used electric elements in the D104 and they worked quite well. > If you want a dynamic element, I suggest the HC4 or HC5 from Heil Sound. I > don't know if Heil is still selling those mic elements separately, but they > do work well in the D104 (and other mics). Bill Coleman, AA4LR, PP-ASELMail: aa...@arrl.net Web: http://boringhamradiopart.blogspot.com Quote: "Not within a thousand years will man ever fly!" -- Wilbur Wright, 1901 __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] D-104 Mic Element Replacement
In the original post, he stated that he specifically did not want an electret element, has found the dynamic replacements and is not interested, but wants a crystal element replacement. Most of the links offered do not offer what he is looking for. So I stand by my original statement with the following qualifier: There are probably some old stock or salvage crystal elements out there somewhere, but good luck finding them. On Tue, Feb 22, 2022 at 6:03 PM Don Wilhelm wrote: > I have used electric elements in the D104 and they worked quite well. > If you want a dynamic element, I suggest the HC4 or HC5 from Heil > Sound. I don't know if Heil is still selling those mic elements > separately, but they do work well in the D104 (and other mics). Just add > enough foam padding to keep the element in place and you are done. > I have a D104 frame with an HC5 element and it works quite well. I also > have a vintage D104 with the original element with an FET in the base > that also works well - the FET is powered by the bias voltage from my K3 > or K2. I know that does not help if the original D104 mic element has > gone bad. > > 73, > Don W3FPR > > On 2/22/2022 8:19 PM, Dr. William J. Schmidt wrote: > > No replacement available... > > > > Well... that's not entirely True. If you search a little, you can find > > places all over the internet where you can buy "old stock" or "removed" > D104 > > elements. Just depends which one/ kind you want. IN FACT just a few > years > > ago I bought a hand full of "authentic Astatic, old stock" the later > crystal > > replacements... brand-new... from one of the big electronic houses like > > Mouser or Digikey (can't remember which one actually). I think they > were in > > the $28 each... > > > > Just search. Here are a couple that I found in 30 seconds: > > > > https://www.theharpmicshop.com/crystal---ceramic-mic-elements.html > > > > http://www.kenselectronics.com/lists/micpart.htm#Cartridges > > > > > > > > > > > > -- Owner, worldwidedx.com AE6LX, Amateur Radio __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] D-104 Mic Element Replacement
Heil HC4/HC5 elements were discontinued many years ago. I believe that DX Engineering sells a similar element for D104's. John KK9A Don Wilhelm w3fpr wrote: I have used electric elements in the D104 and they worked quite well. If you want a dynamic element, I suggest the HC4 or HC5 from Heil Sound. I don't know if Heil is still selling those mic elements separately, but they do work well in the D104 (and other mics). Just add enough foam padding to keep the element in place and you are done. I have a D104 frame with an HC5 element and it works quite well. I also have a vintage D104 with the original element with an FET in the base that also works well - the FET is powered by the bias voltage from my K3 or K2. I know that does not help if the original D104 mic element has gone bad. 73, Don W3FPR __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] D-104 Mic Element Replacement
On Tue, Feb 22, 2022 at 20:19 Don Wilhelm wrote: > I have used electric elements in the D104 and they worked quite well. > If you want a dynamic element, I suggest the HC4 or HC5 from Heil > Sound. I don't know if Heil is still selling those mic elements > separately, but they do work well in the D104 (and other mics). Just add > enough foam padding to keep the element in place and you are done. > I have a D104 frame with an HC5 element and it works quite well. I also > have a vintage D104 with the original element with an FET in the base > that also works well - the FET is powered by the bias voltage from my K3 > or K2. I know that does not help if the original D104 mic element has > gone bad. > > 73, > Don W3FPR > > On 2/22/2022 8:19 PM, Dr. William J. Schmidt wrote: > > No replacement available... > > > > Well... that's not entirely True. If you search a little, you can find > > places all over the internet where you can buy "old stock" or "removed" > D104 > > elements. Just depends which one/ kind you want. IN FACT just a few > years > > ago I bought a hand full of "authentic Astatic, old stock" the later > crystal > > replacements... brand-new... from one of the big electronic houses like > > Mouser or Digikey (can't remember which one actually). I think they > were in > > the $28 each... > > > > Just search. Here are a couple that I found in 30 seconds: > > > > https://www.theharpmicshop.com/crystal---ceramic-mic-elements.html > > > > http://www.kenselectronics.com/lists/micpart.htm#Cartridges > > > > > > > > > > > > __ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:Elecraft@mailman.qth.net > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to w4eb...@gmail.com __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] D-104 Mic Element Replacement
I have used electric elements in the D104 and they worked quite well. If you want a dynamic element, I suggest the HC4 or HC5 from Heil Sound. I don't know if Heil is still selling those mic elements separately, but they do work well in the D104 (and other mics). Just add enough foam padding to keep the element in place and you are done. I have a D104 frame with an HC5 element and it works quite well. I also have a vintage D104 with the original element with an FET in the base that also works well - the FET is powered by the bias voltage from my K3 or K2. I know that does not help if the original D104 mic element has gone bad. 73, Don W3FPR On 2/22/2022 8:19 PM, Dr. William J. Schmidt wrote: No replacement available... Well... that's not entirely True. If you search a little, you can find places all over the internet where you can buy "old stock" or "removed" D104 elements. Just depends which one/ kind you want. IN FACT just a few years ago I bought a hand full of "authentic Astatic, old stock" the later crystal replacements... brand-new... from one of the big electronic houses like Mouser or Digikey (can't remember which one actually). I think they were in the $28 each... Just search. Here are a couple that I found in 30 seconds: https://www.theharpmicshop.com/crystal---ceramic-mic-elements.html http://www.kenselectronics.com/lists/micpart.htm#Cartridges __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] D-104 Mic Element Replacement
Can you not purchase a Heil mic element and wire it to suit? Bill K9YEQ Have a wonderful day! Bill From: elecraft-boun...@mailman.qth.net on behalf of Dr. William J. Schmidt Sent: Tuesday, February 22, 2022 7:40:29 PM To: elecraft@mailman.qth.net Subject: [Elecraft] D-104 Mic Element Replacement No replacement available... Well... that's not entirely True. If you search a little, you can find places all over the internet where you can buy "old stock" or "removed" D104 elements. Just depends which one/ kind you want. IN FACT just a few years ago I bought a hand full of "authentic Astatic, old stock" the later crystal replacements... brand-new... from one of the big electronic houses like Mouser or Digikey (can't remember which one actually). I think they were in the $28 each... Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ PJ2/K9HZ VP2EHZ email: b...@wjschmidt.com __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to k9...@live.com __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
[Elecraft] D-104 Mic Element Replacement
No replacement available... Well... that's not entirely True. If you search a little, you can find places all over the internet where you can buy "old stock" or "removed" D104 elements. Just depends which one/ kind you want. IN FACT just a few years ago I bought a hand full of "authentic Astatic, old stock" the later crystal replacements... brand-new... from one of the big electronic houses like Mouser or Digikey (can't remember which one actually). I think they were in the $28 each... Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ PJ2/K9HZ VP2EHZ email: b...@wjschmidt.com __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] D-104 Mic Element Replacement
On 2/22/2022 11:22 AM, Wilson Lamb via Elecraft wrote: OK, discriminating operators, does anyone know of a good replacement D-104 element. The Shure 444 and other of their mics with numbers in that series have a similar response, specifically tailored for SSB. Shure has always had some hams working in engineering, including some who were top contesters around the time this mic was designed. They're one of the great mic companies, based in Evanston, bordering Chicago. (The other is Electro-Voice, just around the corner of Like Michigan). 73, Jim K9YC __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] D-104 Mic Element Replacement
I thought Heil used to have an element that you could substitute. You had to remove the D104 element. W0MU On 2/22/2022 5:27 PM, Tim Tucker wrote: That element only works on the powered / amplified model. On Tue, Feb 22, 2022 at 2:35 PM Dean Adinolfi wrote: W2ENY element works great. https://www.w2eny.com/ Dean, KD3ANX __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to ae...@worldwidedx.com __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] D-104 Mic Element Replacement
Are you referring to the original non amplified D104? If so, there is no replacement available. There is a lengthy thread about a proposed (dormant) project to recreate the element here: https://www.worldwidedx.com/threads/d-104.241890/ Tim On Tue, Feb 22, 2022 at 11:22 AM Wilson Lamb via Elecraft < elecraft@mailman.qth.net> wrote: > > OK, discriminating operators, does anyone know of a good replacement D-104 > element. > Yes, I have been on the web and see dynamic and electret replacements. My > uses don't involve electret empowered radios. > I also see statements that all the ceramic replacements have been sold, > but I hold out hope. > Does anyone know of a good ceramic element? > Does anyone know if the dynamic/transformer replacement is near the same > sensitivity as the original crystal? > I have three D-104, one of which was my dad's, from the 540s. It's lost > its midrange. > Thanks, > Wilson > W4BOH > > __ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:Elecraft@mailman.qth.net > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to ae...@worldwidedx.com -- Owner, worldwidedx.com AE6LX, Amateur Radio __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] D-104 Mic Element Replacement
That element only works on the powered / amplified model. On Tue, Feb 22, 2022 at 2:35 PM Dean Adinolfi wrote: > W2ENY element works great. > > https://www.w2eny.com/ > > Dean, KD3ANX > __ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:Elecraft@mailman.qth.net > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to ae...@worldwidedx.com > -- Owner, worldwidedx.com AE6LX, Amateur Radio __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] D-104 Mic Element Replacement
W2ENY element works great. https://www.w2eny.com/ Dean, KD3ANX __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
[Elecraft] D-104 Mic Element Replacement
OK, discriminating operators, does anyone know of a good replacement D-104 element. Yes, I have been on the web and see dynamic and electret replacements. My uses don't involve electret empowered radios. I also see statements that all the ceramic replacements have been sold, but I hold out hope. Does anyone know of a good ceramic element? Does anyone know if the dynamic/transformer replacement is near the same sensitivity as the original crystal? I have three D-104, one of which was my dad's, from the 540s. It's lost its midrange. Thanks, Wilson W4BOH __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
[Elecraft] D 104
I very much appreciate the number of responses I have received to my earlier postings - - - Thanks And now I have another problem of how do you connect the 8pin to the 4 wires from the D 104? There is a schematic on the inside of the mike bottom plate but does not address the from 4 to 8 pins. There are 4 wires in the mike cord; a black, a red, white, and copper for ground. I assume the black and red are for the mike and the white for PPT. Charlie White K6TBB San Diego __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] D 104
Charlie, It is difficult to answer from only the wire colors without any diagram. Those colors in the cable can mean most anything - except the shield is ground. According to the Astatic .pdf in G4WPW's extensive list of microphones, the wire colors are: White (audio), Shield (AF Ground), Blue (switch common), Red (PTT), Black (RX Control - no use for most transceivers), Yellow (Receive Ground - seldom used). These colors are for the wires inside the stand - take the bottom cover off to see them. Then you could determine which of those wires connect to which color in the cable. Use your head and your ohmmeter to be certain. Someone may have rewired it according to their own definitions of which color is what. Those mic stands may have been through a lot of hams hands. Work with the colors in the stand rather than the ones in the mic cable. One thing you could do is to confirm the two that are used for the PTT switch - connect two of the wires to your ohmmeter and close the PTT - the two that show continuity when the switch is closed are for PTT - if one of those is blue, that goes to pin 7 or 8 of the mic plug, the other is the PTT line. Examine the wires more carefully to see if one is a shielded wire - that would be th AF and its return would be the shield. The AF connection is to pin 1 and the PTT connects to pin 2 - the returns connect to pins 7 and 8. 73, Don W3FPR On 6/9/2011 2:25 PM, CHARLES WHITE wrote: And now I have another problem of how do you connect the 8pin to the 4 wires from the D 104? There is a schematic on the inside of the mike bottom plate but does not address the from 4 to 8 pins. There are 4 wires in the mike cord; a black, a red, white, and copper for ground. I assume the black and red are for the mike and the white for PPT. Charlie White K6TBB San Diego __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] D 104
On 6/9/2011 11:25 AM, CHARLES WHITE wrote: I assume the black and red are for the mike and the white for PPT. Use an ohmeter to find out. Then study the schematic or connector pinout info in the Elecraft manual to figure out which wire goes to which. You cannot hurt the mic with the ohmeter, and you should hear a in the mic click when the ohmeter leads hit the two wires going to the capsule. 73, Jim K9YC __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
[Elecraft] D 104
I would like to connect a D 104 mike to the K3 but the D 104 is a 4 pin jack and the K3 is 8 pins. I have not been able to find a 8 pin jack for the mike at either MOUSER or DIGIKEY suppliers. Does any one use the D104 with the K3? Any advise? Thanks Charlie White K6TBB San Diego __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] D 104
I use an amplified D-104 with my K3, excellent audio reports. I have also used an un amplified D-104, with equally good reports. Try your local radio shack for the 8 pin jack. 8-Pin Ham Microphone Plug Model: 274-025 | Catalog #: 274-025 $4.19 http://www.radioshack.com/product/index.jsp?productId=2062445 GB 73 K5OAI Sam Morgan On 6/4/2011 12:22 PM, CHARLES WHITE wrote: I would like to connect a D 104 mike to the K3 but the D 104 is a 4 pin jack and the K3 is 8 pins. I have not been able to find a 8 pin jack for the mike at either MOUSER or DIGIKEY suppliers. Does any one use the D104 with the K3? Any advise? Thanks Charlie White K6TBB San Diego __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] D 104
You'd also be well advised, if its an unamplified D-104, to add one of the op-amp matching circuits which can be powered from the K3. It'll make the D-104 look into the 10 megohms or so that it likes and it will sound much more natural. a Quic google search should yield a few of these circuits. Lou WA3MIX - Original Message - From: Sam Morgan k5oai@gmail.com To: elecraft@mailman.qth.net Sent: Saturday, June 04, 2011 1:30 PM Subject: Re: [Elecraft] D 104 I use an amplified D-104 with my K3, excellent audio reports. I have also used an un amplified D-104, with equally good reports. Try your local radio shack for the 8 pin jack. 8-Pin Ham Microphone Plug Model: 274-025 | Catalog #: 274-025 $4.19 http://www.radioshack.com/product/index.jsp?productId=2062445 GB 73 K5OAI Sam Morgan On 6/4/2011 12:22 PM, CHARLES WHITE wrote: I would like to connect a D 104 mike to the K3 but the D 104 is a 4 pin jack and the K3 is 8 pins. I have not been able to find a 8 pin jack for the mike at either MOUSER or DIGIKEY suppliers. Does any one use the D104 with the K3? Any advise? Thanks Charlie White K6TBB San Diego __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] D 104
Or a simple matching transformer -- Hi-Z to Low-Z. But in either case, you can't run a naked D-104 into the K3 mic input. The element needs to see a very high impedance. Grant/NQ5T Sent from my iPhone On Jun 4, 2011, at 1:45 PM, Lou Kolb louk...@gmail.com wrote: You'd also be well advised, if its an unamplified D-104, to add one of the op-amp matching circuits which can be powered from the K3. It'll make the D-104 look into the 10 megohms or so that it likes and it will sound much more natural. a Quic google search should yield a few of these circuits. Lou WA3MIX - Original Message - From: Sam Morgan k5oai@gmail.com To: elecraft@mailman.qth.net Sent: Saturday, June 04, 2011 1:30 PM Subject: Re: [Elecraft] D 104 I use an amplified D-104 with my K3, excellent audio reports. I have also used an un amplified D-104, with equally good reports. Try your local radio shack for the 8 pin jack. 8-Pin Ham Microphone Plug Model: 274-025 | Catalog #: 274-025 $4.19 http://www.radioshack.com/product/index.jsp?productId=2062445 GB 73 K5OAI Sam Morgan On 6/4/2011 12:22 PM, CHARLES WHITE wrote: I would like to connect a D 104 mike to the K3 but the D 104 is a 4 pin jack and the K3 is 8 pins. I have not been able to find a 8 pin jack for the mike at either MOUSER or DIGIKEY suppliers. Does any one use the D104 with the K3? Any advise? Thanks Charlie White K6TBB San Diego __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] D 104
On 6/4/2011 11:45 AM, Lou Kolb wrote: You'd also be well advised, if its an unamplified D-104, to add one of the op-amp matching circuits which can be powered from the K3. As a pro audio engineer, I would advise trying the D104 straight into the K3 and using TX with someone listening to you carefully on the air before going any further. 73, Jim Brown K9YC __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] D 104
That would be a COMPLETE AND TOTAL waste of time. The K3 mic input Z is 600 ohms nominal per spec. The D-104 element needs 500k minimum and better no less than 5M. Last I heard the input stage of a K3 was not a 12AU7/12AX7. That's why Z transformation (preamp, xformer) IS required for this element Grant/NQ5T As a pro audio engineer, I would advise trying the D104 straight into the K3 and using TX with someone listening to you carefully on the air before going any further. 73, Jim Brown K9YC __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] D 104
If an active transformer/buffer is really desired, I recommend staying away from an op-amp circuit. A single-stage JFET transistor uses fewer parts, is generally less susceptible to RF, and there's no voltage-divider bias needed ** -- and still have the benefit of a high-Z input and low-Z output. See my QRZ.com page for D-104 alternatives with the K3. Beware of Google searches on this topic. Most active transformer D-104 circuits I've seen on the web are incorrectly designed and several use superfluous components, the exception being W8JI's design which is similar to the one shown on my QRZ.com page. Paul, W9AC ** Most op-amps are designed for use with bi-polar power supplies. When used with a single-supply rail, the op-amp input must be biased such that the output is 1/2 the supply rail with no input signal present. - Original Message - From: Lou Kolb louk...@gmail.com To: elecraft elecraft@mailman.qth.net Sent: Saturday, June 04, 2011 2:45 PM Subject: Re: [Elecraft] D 104 You'd also be well advised, if its an unamplified D-104, to add one of the op-amp matching circuits which can be powered from the K3. It'll make the D-104 look into the 10 megohms or so that it likes and it will sound much more natural. a Quic google search should yield a few of these circuits. Lou WA3MIX - Original Message - From: Sam Morgan k5oai@gmail.com To: elecraft@mailman.qth.net Sent: Saturday, June 04, 2011 1:30 PM Subject: Re: [Elecraft] D 104 I use an amplified D-104 with my K3, excellent audio reports. I have also used an un amplified D-104, with equally good reports. Try your local radio shack for the 8 pin jack. 8-Pin Ham Microphone Plug Model: 274-025 | Catalog #: 274-025 $4.19 http://www.radioshack.com/product/index.jsp?productId=2062445 GB 73 K5OAI Sam Morgan On 6/4/2011 12:22 PM, CHARLES WHITE wrote: I would like to connect a D 104 mike to the K3 but the D 104 is a 4 pin jack and the K3 is 8 pins. I have not been able to find a 8 pin jack for the mike at either MOUSER or DIGIKEY suppliers. Does any one use the D104 with the K3? Any advise? Thanks Charlie White K6TBB San Diego __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] D 104
On 6/4/2011 12:16 PM, Grant Youngman wrote: That would be a COMPLETE AND TOTAL waste of time. The K3 mic input Z is 600 ohms nominal per spec. Nominal is the operative word here. It's designed to have enough gain for the low impedance mics commonly used with ham gear. If you study the schematic, you see that the mic input stage of a K3 is NOT 600 ohms, it's an opamp, which is a fairly high Z load. The input Z is at least 10K, probably more like 15K -- there's a 10K resistor in series with the input! The D-104 element needs 500k minimum and better no less than 5M. Last I heard the input stage of a K3 was not a 12AU7/12AX7. This whole issue of impedance matching in audio is widely misunderstood. In a passive mic (that is, one that is unamplified), it mainly affects gain and sensitivity. The high-Z D104 is a very hot mic, and the K3 has a LOT of available gain, so you can afford to lose a lot with the mismatch. The second way that impedance CAN affect the sound of a passive mic is frequency response (due to stray L and C in the capsule or output network), but the K3 has VERY good and very flexible TXEQ, which is very likely to be able to correct for any response deviations. That's why Z transformation (preamp, xformer) IS required for this element The mic input stage of the K3 is quite well designed so that it can work very with a wide range of mics. Calling it a 600 ohm input stage is technically WRONG and misleading (just as it misled you). Like I said, I would try the mic first. 73, Jim Brown K9YC __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] D 104
All of the vacuum tube rigs from the 50's that I used with a D-104 had an input impedance of between 500k Ohms and 1 Megohm (the grid resistor of the first speech amplifier stage). Astatic does not list a specific load impedance on the specifications sheet I have. The original D-104 used a Rochelle Salts crystal element which was very sensitive to fracturing from a jolt (don't drop!) and was hydroscopic, which made the life of the element dependent upon the hermetic seal and careful handling. Many of those seals leaked over time which destroyed the element. Later Astatic switched to ceramic elements (like most other mic manufacturers selling Rochelle Salts crystal elements). Ceramic elements are not sensitive to moisture in the air, more resistant to mechanical abuse and still have decent output and a fairly high impedance, which made them popular with owners of rigs designed for crystal mics. One of the enduring features of the D-104 that was certainly responsible for much of its popularity was its frequency response. It was carefully shaped for optimum communications speech. That was critically important back in the days before aggressive speech processing in Ham rigs. The frequency response of even high end rigs was solely limited by the selection of coupling capacitors in the speech amp and, perhaps, the modulation transformer, so a well-designed response in the mic made a huge difference. The D-104 mic specifications show this frequency response: 100 Hz, -10 dB 200 Hz, -3 dB 1 KHz,0 dB 2 kHz, +8 dB 3 KHz, +12 dB 5 kHz, -2 dB 6 kHz, -11 dB 10 kHz, -18 dB Our modern rigs have a frequency response that is almost completely defined by the filters in the SSB generator - at least from a couple hundred Hz to between 2 and 3 kHz. So you can throw away any values outside that frequency range in the above table. What's left is a rising frequency characteristic, which is normally good for communications. If it rises too much when the D-104 is used with the K3, it should be easy to bring it under control with the transmitter equalizer. Considering the K3's design to accommodate low-output mics, I'd be astonished if an external preamp or impedance matching system was required. Ron AC7AC __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] D 104
Changing the termination only modifies the frequency response in the input circuit. What does it matter whether the frequency response is established at the microphone input or later in the audio system? Ron AC7AC -Original Message- From: Grant Youngman [mailto:n...@tx.rr.com] Sent: Saturday, June 04, 2011 3:29 PM To: Ron D'Eau Claire Subject: Re: [Elecraft] D 104 Gain isn't the issue. It's the termination Z. A low Z termination will destroy the frequency response. Why do that and then attempt to fix it with TXEQ? Might as well just do something else from the start . Considering the K3's design to accommodate low-output mics, I'd be astonished if an external preamp or impedance matching system was required. Ron AC7AC __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] D 104
I give :-/ Why use a D-104 if that's the only point? A $3 electret from the shack will do just as well. Hopefully, someone will step in and kill this thread. To the original poster - the simple solution is to use an Astatic stand with a preamp or something similar. Or as Don suggested, try a couple of meg in series with the element and see if the K3 gain is high enough to give you decent audio. If you have to EQ a D- 104, use some other mic. Been using D-104's since 1957, and while I may not be a certified audio engineer, there is nothing wrong with common knowledge. By the way, the ceramic version of this mike has lousy low freq response. You want the crystal element. Grant/NQ5T Sent from my iPhone On Jun 4, 2011, at 5:55 PM, Ron D'Eau Claire r...@cobi.biz wrote: Changing the termination only modifies the frequency response in the input circuit. What does it matter whether the frequency response is established at the microphone input or later in the audio system? Ron AC7AC - __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] D 104
Despite all the solutions presented, the D-104 Lollipop is one of those classic mic frames that just will not give up. I have 2, one with no PTT lever on it (anyone have one for sale?) and another with a Heil HC-5 cartridge instead of the original mic element. For those who have a D-104 frame and an element that does not work, YES, go down to the shack and pick up one of those $3 electret mic elements. Remove the original element and put the electret in its place (with a lot of foam to take up the excess space). Turn on mic bias in the K3 and you will have the classic D-104 mic look with good performance (just as though it were an Elecraft MD2). Be creative, and you too can have a working classic microphone. BTW - I use an Elecraft MD2 mic (no longer available) and like it a lot. 73, Don W3FPR On 6/4/2011 7:25 PM, Grant Youngman wrote: I give :-/ Why use a D-104 if that's the only point? A $3 electret from the shack will do just as well. Hopefully, someone will step in and kill this thread. To the original poster - the simple solution is to use an Astatic stand with a preamp or something similar. Or as Don suggested, try a couple of meg in series with the element and see if the K3 gain is high enough to give you decent audio. If you have to EQ a D- 104, use some other mic. Been using D-104's since 1957, and while I may not be a certified audio engineer, there is nothing wrong with common knowledge. By the way, the ceramic version of this mike has lousy low freq response. You want the crystal element. __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] D 104
Jim and all, Looking at the schematic for the K3 mic input, it is an op amp with a gain of 10. It looks to be a classic differential amplifier with a 10k resistor in both the + and the - inputs. That would produce an input impedance of about 20k ohms. Matching is not necessary (nor desirable). So yes, it is not a 600 ohm input impedance - it is the nominal impedance for a typical driving device which will produce sufficient voltage swing for maximum input - that is a LOT different than matching impedance. In audio applications, this is quite common - the driving impedance is not matched to the input impedance of the receiver. Instead, the impedance of the driving device will dictate the voltage and current required for operation. The op amp only cares about the voltage reaching the input of the IC. The driving voltage will meet the input impedance of the op amp and current will flow. As long as the driving voltage is within the range of voltages expected by the transceiver designer, then the impedance of the driving device does not matter either. In other words, the K3 mic input impedance is a derived value, and has nothing to do with reality - it all has to do with the voltage and current characteristics of the driving device (in this case, the microphone). In other (2nd other) words, do not calculate based on the nominal input impedance of the receiving op amp, it can be very different than stated - the voltage swing is what really matters. Jim is correct - it is quite common to have high input impedance devices in the audio world - maximum power transfer is NOT the goal, but an appropriate voltage swing is required to drive the device, and that is often dictated by the capability of the driving device, and not by the input device. Impedance matching is not required. That has been the case since op amps came into common use in the audio field - no impedance matching, just provide enough voltage swing to operate the op amp as the designer has required. Low impedance driving devices may not provide enough voltage swing - so the 600 ohm specification can be construed as stating a typical 600 ohm driver of the type expected (typical microphone output) will provide sufficient voltage swing for proper operation -- it says nothing about the actual input impedance of the receiver. This is quite different than transmitter PA stage output circuits which require matching to (typically) a 50 ohm impedance for maximum power transfer. 73, Don W3FPR On 6/4/2011 4:03 PM, Jim Brown wrote: On 6/4/2011 12:16 PM, Grant Youngman wrote: That would be a COMPLETE AND TOTAL waste of time. The K3 mic input Z is 600 ohms nominal per spec. Nominal is the operative word here. It's designed to have enough gain for the low impedance mics commonly used with ham gear. If you study the schematic, you see that the mic input stage of a K3 is NOT 600 ohms, it's an opamp, which is a fairly high Z load. The input Z is at least 10K, probably more like 15K -- there's a 10K resistor in series with the input! The D-104 element needs 500k minimum and better no less than 5M. Last I heard the input stage of a K3 was not a 12AU7/12AX7. This whole issue of impedance matching in audio is widely misunderstood. In a passive mic (that is, one that is unamplified), it mainly affects gain and sensitivity. The high-Z D104 is a very hot mic, and the K3 has a LOT of available gain, so you can afford to lose a lot with the mismatch. The second way that impedance CAN affect the sound of a passive mic is frequency response (due to stray L and C in the capsule or output network), but the K3 has VERY good and very flexible TXEQ, which is very likely to be able to correct for any response deviations. __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] D 104
Heil has a really nice 8 pin mic connector (I think it's referred to as a Foster connector) and it's about the same price as the one from Radio Shack but has bit more room inside and fits the radio connector better. HRO has them for $8 to $10 for pack of two. ...bill nr4c -Original Message- From: CHARLES WHITE [mailto:charliewh...@cox.net] Sent: Saturday, June 04, 2011 1:23 PM To: Elecraft@mailman.qth.net Subject: [Elecraft] D 104 I would like to connect a D 104 mike to the K3 but the D 104 is a 4 pin jack and the K3 is 8 pins. I have not been able to find a 8 pin jack for the mike at either MOUSER or DIGIKEY suppliers. Does any one use the D104 with the K3? Any advise? Thanks Charlie White K6TBB San Diego __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] D-104 preamp ...
Does anyone have a design for a FET preamplifier for a D-104 that will work off the K3 mic bias (rather than the separate +8V line) and the typical 3.3V mic bias in the current crop of laptops? Joe, I would try the circuit shown in the link below. http://72.52.250.47/images/ECM.png Referring to the diagram, note that in simplified form the resistor and capacitor as shown are integrated inside the K3 (and laptop PC). Bias (shown as V+) is de/selected from the K3 menu. The cap is inside the K3 and is used to couple and de-clamp the AC portion to the K3's mic circuit. Again, the R and C components shown in the above diagram are a simplified representation of what's in the K3 -- but it's close enough. The common node between the cap and resistor is the K3 mic pin. The K3 then supplies bias to your external nFET (e.g., MPF-102) and D104 element as shown in the dotted capsule area. When bias is active on the K3 mic lead, audio is clamped and elevated to the DC bias potential.of ~ 3VDC to power the nFET. The circuit shown is not a source follower (common drain) that generates less than unity gain, but it is a common source pre-amplifier with a similar attribute of very high input Z. Additional experimentation is needed to optimize the level between the nFET and K3, perhaps by varying the Rs source resistance to ground. The diagram shows no Rs at all. Rd (drain resistance) is the resistor going to V+ in the diagram and is fixed inside the K3. However, the V(gain) expression for a common source FET amp shows that Rs (source resistance) is a denominator value. So, by adding Rs, the circuit gain can be reduced. Although the minimum value of Rd is fixed in the K3, it's possible to add additional Rd at the FET drain. That resistance is also in series with the coupling cap in the K3. By adding more Rd, a voltage divider is created that could impact the operation of the nFET with it's already low +3V at the drain. For that reason, I would start affecting gain by adding Rs instead. Paul, W9AC __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] D-104 preamp ...
I have used the following circuit on a D104 to my K2: http://members.cox.net/n4jk/d104.htm Works great and you wire it for power through the mic connector. Mark W5EZY -- View this message in context: http://elecraft.365791.n2.nabble.com/D-104-preamp-tp5319528p5322031.html Sent from the Elecraft mailing list archive at Nabble.com. __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] D-104 preamp ...
I have used the following circuit on a D104 to my K2: http://members.cox.net/n4jk/d104.htm Works great and you wire it for power through the mic connector. That circuit won't work with the K3's bias on mic pin (Joe's intended use). To work that way with mic bias, power and audio must be joined on one conductor in the same way that an electret condenser element is powered. However, the N4JK circuit will work when using the K3's +8V pin to power the nFET. Also, in its shown configuration as a common-source (source follower) amplifier, I would eliminate the 100pF, 0.01uF input caps, and if absolutely necessary to kill static charge, increase the 2.7-meg shunt R to 10-megs. The common source nFET circuit is self-biased and no gate leak is necessary. The rest of the circuit looks fine. Paul, W9AC __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] D-104 preamp ...
Joe, If you aren't married to the original element you could change it out to an electret element wired directly to the K3 input with the bias turned on. I did that than trying to find a replacement crystal element. The electret element is available from many sources (including your local Radio Shack) for a couple of dollars. Make sure to get the 2 wire version. Otherwise you could create a phantom voltage source in the D104 using a blocking capacitor on the FET output and a diode to a pad-out resistor and filter capacitor. I get good reports on audio quality on my electret but suspect it is the K3 not the microphone! George AI4VZ --- That circuit won't work with the K3's bias on mic pin (Joe's intended use). __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] D-104 preamp ...
George, If you aren't married to the original element you could change it out to an electret element wired directly to the K3 input with the bias turned on. I did that than trying to find a replacement crystal element. If I were going to change the element I would change it to a Heil HC5 or the new HC6 - I am no fan of electrets or bias on the mic line. However, the whole purpose of the FET buffer is to use the outstanding, naturally pre-emphasized (rising) response of the Astatic crystal element on both the K3 and computer soundcard without the need for an external battery box. I suspect the solution lies in an MPF-102 as a common source amplifier with a 470 Ohm resistor in the source lead, 680K to 1M as a gate leak to set the low frequency roll of at around 150 Hz (my preference - since I see absolutely no benefit in reproducing unnecessary and power wasting low frequencies and shack noise) and connect the drain directly to the K3 mic input. The source resistor might need to be adjusted for use with a laptop that only provided 3.3V of bias. Another solution is probably a common emitter NPN transistor with 330K - 1M collector to base, a .47uF - 1uF blocking capacitor to the crystal element with a shunt 1M resistor. However, that would take a lot more experimentation. I was hoping that someone had already solved the problem and could save me some cut and try ... 73, ... Joe, W4TV On 7/21/2010 2:49 PM, George Jan wrote: Joe, If you aren't married to the original element you could change it out to an electret element wired directly to the K3 input with the bias turned on. I did that than trying to find a replacement crystal element. The electret element is available from many sources (including your local Radio Shack) for a couple of dollars. Make sure to get the 2 wire version. Otherwise you could create a phantom voltage source in the D104 using a blocking capacitor on the FET output and a diode to a pad-out resistor and filter capacitor. I get good reports on audio quality on my electret but suspect it is the K3 not the microphone! George AI4VZ --- That circuit won't work with the K3's bias on mic pin (Joe's intended use). __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] D-104 preamp ...
I said it once, and I'll say it again. My 1956 crystal-element D-104 works great with my K3. I plugged it in and did an on-the-air check with K9YC. Jim reported outstanding audio. Before modifying your D-104 or building a preamp, try the bare-bones D-104. K9YC: If you don’t have a problem, don’t solve it. 73, Hank, W6SX Mammoth Lakes, California Elevation 8083 feet in John Muir's Range of Light __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] D-104 preamp ...
I suspect the solution lies in an MPF-102 as a common source amplifier with a 470 Ohm resistor in the source lead, 680K to 1M as a gate leak to set the low frequency roll of at around 150 Hz (my preference - since I see absolutely no benefit in reproducing unnecessary and power wasting low frequencies and shack noise) and connect the drain directly to the K3 mic input. The source resistor might need to be adjusted for use with a laptop that only provided 3.3V of bias. The K3 and the laptop will effectively provide their own drain resistor in a common source configuration. For example, in the K3, bias appears to be turned on/off through Q8 and injected to the mic through R89 on the FP Board. R89 would become the FET's drain resistor (Rd) at 5K, so no new Rd is needed. From R89, audio is coupled through a 1 uF cap at C28 on the Main DSP Board. As a common source amp, a source resistor (Rs) is optional but helps set stage gain. The K3's 5K and 1 uF values are a really good choice since the FET's output Z is roughly equal to the 5K drain resistor. Thevenizing from C28, the cap sees 10K in parallel with 5K, leaving a load of about 3.3K. The -3dB turnover point should be about 48 Hz. When using the K3, it looks like the whole D104 interface can be done with just one external part -- a single MPF-102. That's even simpler than the already simple source follower circuit that's become popular. In your case, one extra gate shunt resistor can be used to optionally limit the low-end response and provide for gate static protection. I would bet the laptop's circuit is close enough if it also provides a switched pull-up resistor (to function as Rd) so that one homebrewed buffer could be built and inter-changed between the laptop and K3. Great concept, Joe! I'll try this the next time I work on an old D104. Paul, W9AC __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
[Elecraft] D-104 preamp ...
Does anyone have a design for a FET preamplifier for a D-104 that will work off the K3 mic bias (rather than the separate +8V line) and the typical 3.3V mic bias in the current crop of laptops? I'd like to avoid providing separate preamp power when the mic is connected to a computer soundcard ... 73, ... Joe, W4TV __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
[Elecraft] D-104, only slightly OT
Good morning, I have an old D-104 that worked fine when last used (1977) and want to use it with the K2. I know I could replace the element with one from Heil, but I would prefer to keep it as original as possible (it does have the preamp in the G stand base). I will assume the preamp works, and I know the K2 works, but I'm not so sure about the original element in the mic. Does anyone know a way to test the element before wiring it up? Thanks es 73, Tom, NG3V ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
Re: [Elecraft] D-104, only slightly OT
The D-104 is an excellent microphone for the K2 (and K3), Tom. Because the ceramic/crystal element is high impedance, your best way of testing it is to wire it up and try it. The pre-set gain control will need to turned fairly well down. Connect it to the 8-way plug: WHITE (or CLEAR) to pin 1 (audio) RED to pin 2 (press to talk) SCREEN to pin 7 (ground) 73 David G4DMP In a recent message, NG3V n...@comcast.net writes I have an old D-104 that worked fine when last used (1977) and want to use it with the K2. I know I could replace the element with one from Heil, but I would prefer to keep it as original as possible (it does have the preamp in the G stand base). I will assume the preamp works, and I know the K2 works, but I'm not so sure about the original element in the mic. Does anyone know a way to test the element before wiring it up? -- David G4DMP Leeds, England, UK ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
Re: [Elecraft] D-104, only slightly OT
I know I could replace the element with one from Heil, but I would prefer to keep it as original as possible (it does have the preamp in the G stand base). Tom, Odds are the crystal element is still in good shape, provided it has not been subjected to a high humidity environment over an extended period of time. Also, anyone contemplating the use of the D-104 with the stock Astatic amp should consider an alternative buffer amp. The input Z to Astatic's 2-stage preamp calculates to 470K-ohm -- way too low for a crystal cartridge. The crystal cartridge should see a termination of no less than 5 megohm, and preferably greater than 10 megohm in order to preserve reasonable low-end response. The series capacitance from a typical crystal cartridge is anywhere from 800pF to 1600 pF. Calculate the - 3dB turnover point into various terminating resistive values and you'll see why it's important to completely unload the crystal cartridge. For simplicity and excellent performance, I favor a single transistor JFET, configured as a near unity-gain source-follower. The web is full of FET and op-amp designs for the D-104, but nearly all of them suffer from inadequate design, particularly with respect to crystal cartridge loading. Most designs I've seen attempt to bias the FET as the analog of a grid leak resistor used on a vacuum tube grid. As a source follower, the FET is completely self-biased when the correct source resistor value is used. The D-104 crystal cartridge can be attached right to the FET's gate with no other components necessary. For isolation, I add a 5-meg resistor in series with the gate, but this is not strictly necessary. If gate failure is a concern from static electricity, some ops have used a 10-megohm resistor from the gate to ground in an attempt to bleed static build-up.. I've never found this to be necessary. If all of the above sounds like too much work, simply insert a 10-megohm resistor between the D-104 cartridge and Astatic's 2-stage preamp. Signal to noise and distortion performance will suffer, but at least the cartridge will be unloaded. The Astatic preamp can more than compensate for the loss in level owing to the use of the series resistor. When the K3 is configured for ESSB transmit, the D-104 will sound nearly as good as an expensive studio condenser or dynamic mic. As a final footnote, I recommend ESSB only for use on uncrowded bands, and when signal strength is high. Otherwise, it's a waste of occupied bandwidth. Paul, W9AC ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
Re: [Elecraft] D-104, only slightly OT
Do you have an audio amplifier, a mic input on your sound card or even a pair of headphones around? Try the mic with them. Any audio in the phones is likely very low level but you might hear something in the typical 50-ohm computer or game headsets around today. Some clip leads and a suitable connector are all you need -- ground and hot lead -- to whatever If you have an o'scope, it'll show audio too. (Of course you have to make noise near the element ;-) If you hear or see *any* response from the element, it's likely good. Those old crystal and ceramic elements tended to work fine or not at all. Be sure the amp in the base has a good battery in it: 9V IIRC. Ron AC7AC -Original Message- Good morning, I have an old D-104 that worked fine when last used (1977) and want to use it with the K2. I know I could replace the element with one from Heil, but I would prefer to keep it as original as possible (it does have the preamp in the G stand base). I will assume the preamp works, and I know the K2 works, but I'm not so sure about the original element in the mic. Does anyone know a way to test the element before wiring it up? Thanks es 73, Tom, NG3V ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
Re: [Elecraft] D-104, only slightly OT
Paul, W9AC, wrote: Also, anyone contemplating the use of the D-104 with the stock Astatic amp should consider an alternative buffer amp. The input Z to Astatic's 2-stage preamp calculates to 470K-ohm -- way too low for a crystal cartridge. The crystal cartridge should see a termination of no less than 5 megohm, and preferably greater than 10 megohm in order to preserve reasonable low-end response. --- The Astatic D-104 was designed as a *communications* microphone with a carefully shaped frequency response for speech and not for extreme high or low frequency response. The graph of the audio response published by Astatic, using the built in amplifier, shows 0 dB at 1 kHz. Below 1 kHz the output drops off smoothly to -5 dB at about 200 Hz, then more steeply down to -10 dB at 100 Hz where the published curve ends. That roll-off is important since excessive low frequency response robs a signal of intelligibility and punch since the bulk of the energy, but virtually none of the modulation in the spoken voice is down in those ranges. Above 1kHz, the output rises smoothly to a peak a bit above +10 dB at 3 kHz, the smoothly drops off to almost - 20 dB at 10 kHz. That rising characteristic to a peak in the roughly middle point of the speech audio spectrum is what made it so effective in communications and made it so popular. Ron AC7AC ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
Re: [Elecraft] D-104, only slightly OT
The Astatic D-104 was designed as a *communications* microphone with a carefully shaped frequency response for speech and not for extreme high or low frequency response. Although the presence rise was a design attribute of the mic, limited low-end response was not. The D-104 was produced in the early 1930s as a communications microphone intended for reasonably good, balanced audio response in the AM mode -- not SSB. SSB as used in radio communications is a post D-104 phenomenon. Use of the D-104 pre-dates common SSB use in the amateur service by 20 years. According to Astatic, their 2-stage buffer amp was designed as an active impedance transformer as low-Z solid-state devices were being ushered-in during the 60s Astatic never intended for the preamp to be used as a power mic device. It was the Citizen's Band operators who made the added gain function popular. That said, Astatic could have designed a much better buffer for the D-104. The graph of the audio response published by Astatic, using the built in amplifier, shows 0 dB at 1 kHz. Below 1 kHz the output drops off smoothly to -5 dB at about 200 Hz, then more steeply down to -10 dB at 100 Hz where the published curve ends. The typical D-104 with 2-stage preamp is substantially more response limited than that shown in Astatic's graph. The response plot shown in their instruction sheet is hardly a scientific measurement and the response can vary considerably across cartridges. That roll-off is important since excessive low frequency response robs a signal of intelligibility and punch since the bulk of the energy, but virtually none of the modulation in the spoken voice is down in those ranges. True of weak signal communications. Not true when the SNR is high - and the reason for the disclaimer at the end of my post. If your theory is correct, I doubt Elecraft would have included ESSB as a design feature into the K3, The lowest fundamental of the deepest male voice can be measured as low as 70 Hz -- and is typically 75-85 Hz. It's not that spoken voice does not produce frequencies that low, it's that historically, SSB transmissions have been deliberately bandwidth-limited. That rising characteristic to a peak in the roughly middle point of the speech audio spectrum is what made it so effective in communications and made it so popular. The D-104 became popular for a variety of reasons including cost, aesthetics, availability in the golden age of AM, reasonably good and balanced frequency response, etc. Paul, W9AC ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
Re: [Elecraft] D-104, only slightly OT
I've been using the setup you describe with a K-2 for about 10 years without problems. In fact I've gotten a few unsolicited compliments on audio over the years. Mine is wired just like David Pratt described. I have the K-2 set for SSBA-1 (attenuator in) and the mic gain pot about half way up. I just turn up the pot until 1 ALC led blinks a bit on voice peaks. To test, hook it up and ask a friend how it sounds! 73, Lenny W2BVH ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
Re: [Elecraft] D-104, only slightly OT - Redux
To all who took the time to reply - Thank You. I've been wanting to do this since I finished the K2 but have never gotten around to it. I bought the Heil desk mic and classic stand with the K2 and I guess I'll have to sell it now to force my own hand. 73, Tom -Original Message- From: elecraft-boun...@mailman.qth.net [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of w2bvh Sent: Tuesday, January 20, 2009 4:52 PM To: Elecraft@mailman.qth.net Subject: Re: [Elecraft] D-104, only slightly OT I've been using the setup you describe with a K-2 for about 10 years without problems. In fact I've gotten a few unsolicited compliments on audio over the years. Mine is wired just like David Pratt described. I have the K-2 set for SSBA-1 (attenuator in) and the mic gain pot about half way up. I just turn up the pot until 1 ALC led blinks a bit on voice peaks. To test, hook it up and ask a friend how it sounds! 73, Lenny W2BVH ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
[Elecraft] D-104 and Radio Shack electret element
Lots of mike comments have caused me to remember that I have a D-104. And am waithing for a K3. Has anyone put a Radio Shack electret element into a D-104 and used it on a K3? I want to plug into the rear mike jack. Tips anyone? Thanks. 73, Ty, W1TF K1 #1423 Looking for last minute shopping deals? Find them fast with Yahoo! Search. http://tools.search.yahoo.com/newsearch/category.php?category=shopping ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
Re: [Elecraft] D-104 and Radio Shack electret element
Ty, I have not tried an electret element, but I have a Heil HC-5 element in my D-104 frame that I have been quite pleased with. I made my own 'filling' for the much smaller sized element, but Heilsound does sell a kit for just that purpose. Just use connectors for the AF and PTT that mate with the K3 rear connectors and you should be all set. I recommend shielded wire all the way for the AF and AF ground wires. 73, Don W3FPR Ralph Tyrrell wrote: Lots of mike comments have caused me to remember that I have a D-104. And am waithing for a K3. Has anyone put a Radio Shack electret element into a D-104 and used it on a K3? I want to plug into the rear mike jack. Tips anyone? Thanks. 73, Ty, W1TF K1 #1423 ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
Re: [Elecraft] D-104 and Radio Shack electret element
I have not tried it on the K3, but I have done this many times in the past with other rigs. I know W5JAY has played around with that also on his Pro III, and got very favorable comparisons with his Heil microphones. All you need to do is find some old microphone housing, put in the RS electret element, and wire it appropriately. I think you will be pleasantly surprised! Dave W7AQK - Original Message - From: Ralph Tyrrell [EMAIL PROTECTED] To: Elecraft@mailman.qth.net Sent: Thursday, February 14, 2008 10:02 AM Subject: [Elecraft] D-104 and Radio Shack electret element Lots of mike comments have caused me to remember that I have a D-104. And am waithing for a K3. Has anyone put a Radio Shack electret element into a D-104 and used it on a K3? I want to plug into the rear mike jack. Tips anyone? Thanks. 73, Ty, W1TF K1 #1423 Looking for last minute shopping deals? Find them fast with Yahoo! Search. http://tools.search.yahoo.com/newsearch/category.php?category=shopping ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
Re: [Elecraft] D-104 and Radio Shack electret element
you might be able to place an electret element in the case and leave the original element in there You'd have to rewire since the astatic has a 3 conductor plug on the mic housing. I have placed an electret ( small ) in front of a dynamic AKG element in my current station microphone, and cannot hear any acoustic interference. bill ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
RE: [Elecraft] D-104 and Radio Shack electret element
The Astatic crystal element exactly fits the lollipop housing. It's THAT big! But it's no problem to remove and rewire. The lollipop top even unplugs from the stand. Unlike a lot of modern desk and hand mics, the D-104 was designed around the element, rather than coming up with a design for the case and plunking the element inside! That was true of most of the old microphones. For example, the Heil Heritage microphone is a copy of the old ribbon microphones used for broadcasting in the 1930's and 40's. The long, tall shape of the enclosure was dictated by the shape of the microphone inside, which used, literally, a ribbon of flexible metal in a magnetic field. Another enclosure for the same ribbon element is the Heil Classic that was another 'standard' in broadcasting studios everywhere. In both cases, the pop screen so often seen put in front of the microphone today is part of the mic and dictates the separation from the grille and the element inside. It's placed just inside the metal openings. Similarly, the more round mics were either miniature crystal elements or dynamic elements which were that size! Heil has used these designs for good reason. People associate those mics with quality and performance, based on old associations. Heil can use them because today's elements are so small they can be put inside almost any traditional enclosure. Even the most technical of us still responds to fashion -- at least some of us do. Ron AC7AC -Original Message- you might be able to place an electret element in the case and leave the original element in there You'd have to rewire since the astatic has a 3 conductor plug on the mic housing. I have placed an electret ( small ) in front of a dynamic AKG element in my current station microphone, and cannot hear any acoustic interference. bill ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
RE: [Elecraft] D-104 Mic freq reesponse
At 04:03 PM 2/23/2007, Ron D'Eau Claire wrote: Unlike almost all modern mics, the original D-104 has a shaped frequency response curve for optimum speech quality. It has a broad peak in the 3 kHz not unlike all modern mics, the Shure SM58... is probably the world's most popular mic model... which has/had been the standard of the rocknroll industry since Heil was a pup. The SM58 has a tailored vocal response for a sound which is a world standard. Rugged construction, a proven shock mount system, aspeech - the SM58 is the overwhelming choice of professionals. The legendary Shure vocal mic is tuned to accentuate the warmth and clarity of lead and back-up vocals. Consistently the first choice of performers around the globe... ;;it's up 5 db at 4khz... bill ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
[Elecraft] D-104 Mic
I have been reading about the different microphones used by fellow K2 owners. A fellow ham encouraged me to try a vantage, (1960s) D-104 crystal mic for the K2. I had been using a Kenwood MC-48B and it was working OK. I knew that the straight D-104 mic would not work with the K2 as crystal mics are hi Z and the modern solid state Mic inputs are low Z. One model of D-104 however has an amp in it's base and it works fine. I get better signals quality report with the D-104 then my previous mic. I don't mind that the mic towers almost a foot over my K2 as I have big hands anyway. Just another Idea. Don...KA7L BRBRBR**BR AOL now offers free email to everyone. Find out more about what's free from AOL at http://www.aol.com. ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
Re: [Elecraft] D-104 Mic
heh heh I loved your line ... towers almost a foot over my K2 man, the mike is bigger than the radio! I can visualize a ham wrestling with a giant mike connected to a teeny radio ... That brought smiles to my face, thank you. Ron, wb1hga Elmer the inquisitive [EMAIL PROTECTED] wrote: I have been reading about the different microphones used by fellow K2 owners. A fellow ham encouraged me to try a vantage, (1960s) D-104 crystal mic for the K2. I had been using a Kenwood MC-48B and it was working OK. I knew that the straight D-104 mic would not work with the K2 as crystal mics are hi Z and the modern solid state Mic inputs are low Z. One model of D-104 however has an amp in it's base and it works fine. I get better signals quality report with the D-104 then my previous mic. I don't mind that the mic towers almost a foot over my K2 as I have big hands anyway. Just another Idea. ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
RE: [Elecraft] D-104 Mic
Unlike almost all modern mics, the original D-104 has a shaped frequency response curve for optimum speech quality. It has a broad peak in the 3 kHz range to pick up the sibilance essential for intelligibility, with good roll-off characteristics at the higher and lower frequencies. Since filter SSB rigs (like the K2) became the norm, I've noticed that more and more communications mics are simply the same old hi-fi elements packaged for Ham use. They depend upon the filter characteristics of the rig to limit the high and low frequency response, and generally do not provide any rising characteristic in the 3 kHz range that can produce the clear, bright audio that helps intelligibility, especially when copying a signal under rough conditions. Remember that when the D-104 came out, rigs didn't have filters! The speech was shaped slightly by choosing the right combinations of resistors and capacitors in the speech amplifier but generally any frequency between a few Hz and 10kHz (or more) that came into the mic went out the antenna, so a mic with proper shaping was an essential element of any good 'phone station back then. It's a great mic and a real icon. If yours has the original element, it may well be a Rochelle salts crystal element. Of so you're fortunate it's survived. They are easily destroyed by physical shock (knocking the mic over or dropping it) and temperature extremes. If you open the lollipop top, you'll see the element suspended in rubber inside the ring to help protect it from shock. The Rochelle salts crystal is also water soluble. If exposed to high humidity for any length of time, they dissolve! The element was hermetically sealed when it was made, but it seems that some of the seals fail over time (or curious fingers broke them). Rochelle salts elements were replaced by ceramic elements in most microphones at some point in the late 50's and 60's , but I don't know if Astatic ever went to a ceramic element for the D-104. Ceramic elements are lot more stable and strong, but not virtually indestructible like most modern dynamic and electret mics! Without specific data, I'd assume it's a Rochelle salts crystal and treat it like royalty. After all, among mics, the D-104 definitely qualifies. Ron AC7AC -Original Message- I have been reading about the different microphones used by fellow K2 owners. A fellow ham encouraged me to try a vantage, (1960s) D-104 crystal mic for the K2. I had been using a Kenwood MC-48B and it was working OK. I knew that the straight D-104 mic would not work with the K2 as crystal mics are hi Z and the modern solid state Mic inputs are low Z. One model of D-104 however has an amp in it's base and it works fine. I get better signals quality report with the D-104 then my previous mic. I don't mind that the mic towers almost a foot over my K2 as I have big hands anyway. Just another Idea. Don...KA7L ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
RE: [Elecraft] D-104 Mic
Don, There was a report somewhere within the past few months that one ham successfully used his unamplified D-104 with a low impedance rig (it may have been a K2). He simply added a series resistor to keep the mic looking into a high impedance and it worked fine. I have not tried it here, but I would recommend that you use a series resistor value greater than 470k ohms. The D-104 element has plenty of output voltage. The amplified D-104s work just fine with low mic input impedance transceivers. You could search the reflector archives in case it was on this reflector (I do think it was, but my memory is fuzzy). Don W3FPR -Original Message- I have been reading about the different microphones used by fellow K2 owners. A fellow ham encouraged me to try a vantage, (1960s) D-104 crystal mic for the K2. I had been using a Kenwood MC-48B and it was working OK. I knew that the straight D-104 mic would not work with the K2 as crystal mics are hi Z and the modern solid state Mic inputs are low Z. One model of D-104 however has an amp in it's base and it works fine. I get better signals quality report with the D-104 then my previous mic. I don't mind that the mic towers almost a foot over my K2 as I have big hands anyway. Just another Idea. Don...KA7L -- No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.5.441 / Virus Database: 268.18.3/699 - Release Date: 2/23/2007 1:26 PM ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
Re: [Elecraft] D-104 Mic
On Feb 23, 2007, at 2:03 PM, Ron D'Eau Claire wrote: It's a great mic and a real icon. If yours has the original element, it may well be a Rochelle salts crystal element. Of so you're fortunate it's survived. They are easily destroyed by physical shock (knocking the mic over or dropping it) and temperature extremes. If you open the lollipop top, you'll see the element suspended in rubber inside the ring to help protect it from shock. The Rochelle salts crystal is also water soluble. If exposed to high humidity for any length of time, they dissolve! The element was hermetically sealed when it was made, but it seems that some of the seals fail over time (or curious fingers broke them). I dropped my D-104 several months after I bought it (around 50 years ago) and know well what you mean. I mailed the head to Astatic asking them to replace the element and let me know how much it would cost. The repaired mike was sent back to me a week later--no charge! I still have it and wonder what shape the element is in. I may throw together a transistor amp and give it a try with my K2 one of these days. Bob, N7XY ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
RE: [Elecraft] D-104 Mic
Ouch!! That's a great story though. I got similar personal support from the National company back in the 60's. Elecraft's excellent customer support isn't something new; it's just something that's been missing from too many companies for too many years. You might try the suggestion Don Wilhelm made: put a large (appx 470k ohm) resistor in series with the hot side of the mic and drive the K2 directly with it. He's heard that it still has enough gain to work that way. Of course, the large resistor is essential to preserve the frequency response characteristic: that is affected by the load impedance on the output. Ron AC7AC -Original Message- I dropped my D-104 several months after I bought it (around 50 years ago) and know well what you mean. I mailed the head to Astatic asking them to replace the element and let me know how much it would cost. The repaired mike was sent back to me a week later--no charge! I still have it and wonder what shape the element is in. I may throw together a transistor amp and give it a try with my K2 one of these days. Bob, N7XY ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
[Elecraft] D-104, redux
Hi Group, Thanks to Ron and Tom. The E/H switch is, apparently, a method of going from E (electronic) to H (hand) control. However, I will have to rewire the whole thing to use VOX as the amplifier is also switched on by the hand switch. Wiring the amplifier to run continuously would probably be detrimental to the health of the 9 V battery, so I'll have to look elsewhere for some juice. I think I will see if the amp will run off the 5 V from the K2. Everything should be easy then. Don't think it would be worth the trouble to replace the amp with a newer design that I know would be happy with 5V. Of course we still have the issue of somewhat less than real good VOX, but I just hate to have a capability I can't use. I'll post results when I have time to give it a try. Tom, KJ3D ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
[Elecraft] D-104
Hello Group, After seeing several messages about the D-104, I decided mine looked better in the shack than on the shelf in my study, so I spent some quality time with it this weekend. It has the preamp built in the base, and the little schematic glued to the base is dated 9-75 which is about when I got it. Wiring it up was no problem and it seems to drive the K2 just fine, but I have a couple of questions. 1. There is a switch on the board labeled E and H. Can't for the life of me figure out why it is there. Seems to only switch one side of the push to talk switch from ground or the other push to talk line. So what's the E and H? 2. Has anyone tried running one of these off the K2 5V line available at the mic jack instead of the internal 9 V battery? VOX won't work as is because the preamp is switched in and out with the push to talk lever. Thanks in advance, 73, Tom, KJ3D (Formerly W3QS) ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
Re: [Elecraft] D 104 mic with K2
Ron, My first reply bounced so here it is again. - Ron, On their Web page, Astatic does not give the value of the Base to Collector resistor value in the first stage of the the preamp but they do for the same resistor in the second stage. Have you any idea what it might be? On 9/27/05, Ron D'Eau Claire [EMAIL PROTECTED] wrote: Don has it right, but it depends upon how new the D-104 is. The versions made the last 20 years or so, using the same D-104 high-impedance crystal element we hooked to our tube transmitters half a century back, now has a transistor amplifier/impedance matching unit in the base. If your unit has a base plate in the stand that takes a battery, you have one of the newer units designed for modern rigs. The schematic of the D-104 amplifier and a nice graph of what a great communications microphone frequency response curve looks like are at the Astatic site: http://www.astatic.com/cb/d104.htm It should be pretty simple to duplicate if you have one of the older mics. Just about any NPN transistor can be used (2N, etc). Ron AC7AC -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of W3FPR - Don Wilhelm Sent: Tuesday, September 27, 2005 5:13 PM To: [EMAIL PROTECTED]; elecraft@mailman.qth.net Subject: RE: [Elecraft] D 104 mic with K2 The D 104 mic (unamplified version) needs to look into a very high impedance (50k ohms or greater). That mic was developed in the days of vacuum tubes with mic amplifier input inpedances in the 50k to 1 megohm range. Modern transceivers present an impedance of something close ot 600 ohms at the mic input jack, so to properly use a D 104 with modern transceivers, you will need an amplifier stage - the gain can be low, but the input impedance must be very high and the design output impedance should be in the vicinity of 600 ohms. A few circuits to do that have been published in QST over the past 2 or 3 years. Sorry, but I don't have a specific issue reference. I took a different route with my D 104, I put a Heil HC-5 element in the D 104 head - it works FB, but the Heil elements need about 3 to 6 dB of gain to properly drive the K2, so a preamp stage is still needed (or the KI6WX increased gain mod of the KSB2 - which is what I use). 73, Don W3FPR ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com -- John [K7SVV] ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
Re: [Elecraft] D 104 mic with K2
In message [EMAIL PROTECTED], John [K7SVV] [EMAIL PROTECTED] writes On their Web page, Astatic does not give the value of the Base to Collector resistor value in the first stage of the the preamp but they do for the same resistor in the second stage. Have you any idea what it might be? It is 1.5 Megohms on the D.104 that I have. 73 de David G4DMP ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
[Elecraft] D 104 mic with K2
I would like to try the D 104 Mic. (crystal element ) in the K2 . I remember a circuit posted on the reflector on this , can anyone help ? Thanks ,72, 73, Jerry Uhte K9UT K2 # 1273 ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
RE: [Elecraft] D 104 mic with K2
The D 104 mic (unamplified version) needs to look into a very high impedance (50k ohms or greater). That mic was developed in the days of vacuum tubes with mic amplifier input inpedances in the 50k to 1 megohm range. Modern transceivers present an impedance of something close ot 600 ohms at the mic input jack, so to properly use a D 104 with modern transceivers, you will need an amplifier stage - the gain can be low, but the input impedance must be very high and the design output impedance should be in the vicinity of 600 ohms. A few circuits to do that have been published in QST over the past 2 or 3 years. Sorry, but I don't have a specific issue reference. I took a different route with my D 104, I put a Heil HC-5 element in the D 104 head - it works FB, but the Heil elements need about 3 to 6 dB of gain to properly drive the K2, so a preamp stage is still needed (or the KI6WX increased gain mod of the KSB2 - which is what I use). 73, Don W3FPR -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of [EMAIL PROTECTED] Sent: Tuesday, September 27, 2005 7:39 PM To: elecraft@mailman.qth.net Subject: [Elecraft] D 104 mic with K2 I would like to try the D 104 Mic. (crystal element ) in the K2 . I remember a circuit posted on the reflector on this , can anyone help ? Thanks ,72, 73, Jerry Uhte K9UT K2 # 1273 ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com -- No virus found in this incoming message. Checked by AVG Anti-Virus. Version: 7.0.344 / Virus Database: 267.11.6/111 - Release Date: 9/23/2005 -- No virus found in this outgoing message. Checked by AVG Anti-Virus. Version: 7.0.344 / Virus Database: 267.11.6/111 - Release Date: 9/23/2005 ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
RE: [Elecraft] D 104 mic with K2
Don has it right, but it depends upon how new the D-104 is. The versions made the last 20 years or so, using the same D-104 high-impedance crystal element we hooked to our tube transmitters half a century back, now has a transistor amplifier/impedance matching unit in the base. If your unit has a base plate in the stand that takes a battery, you have one of the newer units designed for modern rigs. The schematic of the D-104 amplifier and a nice graph of what a great communications microphone frequency response curve looks like are at the Astatic site: http://www.astatic.com/cb/d104.htm It should be pretty simple to duplicate if you have one of the older mics. Just about any NPN transistor can be used (2N, etc). Ron AC7AC -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of W3FPR - Don Wilhelm Sent: Tuesday, September 27, 2005 5:13 PM To: [EMAIL PROTECTED]; elecraft@mailman.qth.net Subject: RE: [Elecraft] D 104 mic with K2 The D 104 mic (unamplified version) needs to look into a very high impedance (50k ohms or greater). That mic was developed in the days of vacuum tubes with mic amplifier input inpedances in the 50k to 1 megohm range. Modern transceivers present an impedance of something close ot 600 ohms at the mic input jack, so to properly use a D 104 with modern transceivers, you will need an amplifier stage - the gain can be low, but the input impedance must be very high and the design output impedance should be in the vicinity of 600 ohms. A few circuits to do that have been published in QST over the past 2 or 3 years. Sorry, but I don't have a specific issue reference. I took a different route with my D 104, I put a Heil HC-5 element in the D 104 head - it works FB, but the Heil elements need about 3 to 6 dB of gain to properly drive the K2, so a preamp stage is still needed (or the KI6WX increased gain mod of the KSB2 - which is what I use). 73, Don W3FPR ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
[Elecraft] D-104 sold other various off-topic comments
Thanks for the many replies; mic is sold. To the M who can't find the parts locations: I have the same problem. But, it gets logarithmically easier as you populate the board! Once a location is filled your eyes/brain don't have to 'scan' there any more, and so finding the missing places gets MUCH easier as you go along. Not unlike a jigsaw puzzle. To the K who likes the SWL PSKxx rigs but laments their being rockbound and sans tuner: someone else already commented you don't need a VFO, by design, and I'll add ... because they are monoband units, field operations with these rigs are ENHANCED because you can BRING a pre-built monoband antenna with you. I think it'd be daft for Aptos to cook up a rig that competes with something already mightily well done, and the new versions from K1SWL require no serial port. For the PSK20, I suggest a sloper made of a folded dipole. You can make one from some 300 ohm twinlead. Use a piece for a phasing line, and with just one small capacitor, you can get it to a 50 ohm point VERY easily. Quick to roll up, a snap to deploy, only 1 vertical support needed, cheap, always works like a champ. ___ Do you Yahoo!? Declare Yourself - Register online to vote today! http://vote.yahoo.com ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
