Re: [drakelist] R8B Low Sensitivity?????
100 feet for a long-wire is not long compared to the wavelength at 60[kHz], which is appr. 5000[m] or appr. 16000 feet. So, the length of the antenna is appr. 1/160th of the wavelength - an indication, that it will not develop much voltage at this frequency. Maybe testing a magnetic antenna - like a loop with some windings and a diameter of 1...2[m] maybe a suggestion? The second suggestion will be, to measure the receivers sen- sivity. At this frequency, an reasonable function generator capable of a low-distortion sine output, followed by a home- brewn, shielded, multistage resistive attenuator (in the range of 80...100[dB], depending on the generators capability of output level variation), should do the job as a substitute for a calibrated signal generator. Amplitude caibration of the generator at it's output terminals should not be a problem with any common and cheap "20[MHz] style" analog oscilloscope with a accuracy that is sufficient for ham needs. vy73 de Herbert, DG7MCC Jim schrieb: Jim <[EMAIL PROTECTED]> made an utterence to the drakelist gang -- I am using a late serial number Drake R8B that the display shows it will tune down to 10kHz. Also the serial number is high enough that Drake says the radio will tune and receive below 100kHz. The issue is my R8B seems deaf below 100 kHz. I connect a long wire (100 feet) to the Hi-Z input and cannot even hear a whisper of WWVB at 60kHz. I have also tried a 40 meter dipole on the Lo-Z input and an active whip on the Lo-Z input with the same results. I can put the radio in the LSB mode and there is zero hint of a carrier on 60kHz. Do other Drake R8B owners have the same experience? I sent a mail to Drake and they came back saying the radio sensitivity is not spec'ed below 100kHz. That info is of little help. The did say I could send the radio into them for $25 per hour to have it checked out, but if the radio is poor (by design) below 100 kHz, why waste the money. Also, someone told me that they had a similar problem and it was a defective I.C. So...are there other Drake R8B owners that have a radio that can "hear" below 100 kHz (WWVB for example)?? I am located in the San Diego, Ca area. Thanks again. Jim -- On Behalf of Jim <[EMAIL PROTECTED]> Submissions: [EMAIL PROTECTED] Unsubscribe: [EMAIL PROTECTED] - unsubscribe drakelist in body Hopelessly Lost: [EMAIL PROTECTED] - help in body of message Zerobeat Web Page: http://www.zerobeat.net Brought to you courtesy of TLCHost.net http://www.tlchost.net/ --
Re: [drakelist] TR7
!!! This is a personal message for Don Cunningham, WB5HAK !!! Don, as i got the following error message from your mailserver / provider, i post my message public in order to get in touch with you (please see my personal message below after this error message): The original message was received at Thu, 2 Sep 2004 19:27:43 +0200 (MEST) from pD9E96971.dip.t-dialin.net [217.233.105.113] - The following addresses had permanent fatal errors - <[EMAIL PROTECTED]> (reason: 550 5.7.1 <[EMAIL PROTECTED]>... ACCESS DENIED to natnoddy.rzone.de by okrbl) - Transcript of session follows - ... while talking to mail.sirinet.net.: >>> DATA <<< 550 5.7.1 <[EMAIL PROTECTED]>... ACCESS DENIED to natnoddy.rzone.de by okrbl 550 5.1.1 <[EMAIL PROTECTED]>... User unknown <<< 503 5.0.0 Need RCPT (recipient) Here is my original message: Dear Don, i am interested in your offer and i'm willing to pay the US$ 600,-- four your offer without discussion, and additionally all shipment and handling costs that will arise from that deal. The "problem": I'm located in Germany. Are you willing to handle this deal with a german ham? I have regular experience in doing business with the United States (as i'm the boss of a company that frequently purchases goods from there), so the payment procedure and the else should not be a major problem. Thanks in advance for your answer. Kind regards and vy73 from Herbert Schulz, DG7MCC Don and Diana Cunningham schrieb: I have a very nice, loaded TR7/PS7 for sale or trade. It has 1800, 6kc, 600 cycle filters, FA7 on the transceiver, NB7 and AUX7, original manual. Serial number is 9854, so late one. Excellent condition electrically and cosmetically. Asking $600 plus some shipping or trade for Drake L4B amp in similar shape.Tks,Don, WB5HAK
Re: [drakelist] Herbert's letter
May i add a few last words to this topic "miracoleous inven- tions (antennas) and the follow ups" i forgot in my letter before: The design of the Drakes (i name the "4-line", to be honest, as i never have seen a "7" or it's successors in technical (schematic) detail) is straightforward and simplicity itself. O.k., this goes also for design details like the class "A" final audio amplifier in the R4-C or the very high-impedance AGC-line in the SPR-4, but there are a lot of reasonable modi- fication solutions available. Besides the drawing style of the schematics, everything associated with the working principle of this gear is relatively easy to understand if one is familiar with rf and electronics basics. Nevertheless, this kind of equipment could easily be main- tained and repaired by hams (and our license implies that we are allowed to build, modify and repair our equipment by ourselves) with a minimum of fancy test gear - and: at least for the semiconductors, there is always one drop in re- placement available. No "expensive and hard to get" spe- cial IC's, no "black functional block" in the schematic nobody understands, no tiny SMD-IC's with 120+ pins where one needs a magnification glass to distinguish the indi- vidual pins, no need for costly super-precise signal ge- nerators, spectrum analyzers, logic test stuff and the else. Evermore, you remove the top and bottom cover and have full access to every component while the unit still is fully operative - no special test cables, no extender boards or other special stuff that will cost you a for- tune - nothing. I have access to lab-grade test gear, however, i did all the work on my Drakes with a minimum of test equipment and some phantasy with full success - and i verified this work with the professional test gear. Result: Every- thing is meeting the specifications stated in the manuals. To my knowledge, there is not much more "modern" ham gear on the market, that could claim the same simplicitiy for itself. So long for this topic. Herbert, DG7MCC Mike Williams schrieb: Herbert, well said!
Re: Fw: [drakelist] Interesting? Not Really!
I think, the best thing to treat unbelievable inventions is to judge them with common sense. And then it easily would appear, that the laws of physics apply even in today's modern times (o.k., Einstein changed some views of the Newton based physics theory, but the general concepts - like wavelenght, propagation time of a wave in a medium and the else - are still in place - also for antennas). To me it appears pretty much the same like with those "audiophiles" that claim to have invented the ultimate bass loudspeaker producing substantial sound pressure at 20 hertz yet having only 5 liters in cubical volume - something, that is hard to proove by physics. Back to the issue of our Drake's: What Bob Drake did, is simple yet very necessary serious thinking: He applied the laws of physics - maybe also intuitive - to the gear he designed. And that means in example: Only a inductor of substantial mechanical size and proper mechanical construction will have a high Q - and there are a lot of them to be found in an R4-C or an SPR-4, for example. That means, that receivers and transmitters need a sturdy mechanical construction in order to maintain some frequency stability. That means, that one have to close the window as much as possible for unwanted signals (to preselect them) by means of passive high-quality devices before the first active nonlinear device (preamp or, even worse, the mixer) sees them. In todays money-driven world, however, this is a expensive con- struction and manufacturing technique because it can not be pro- duced on a fully automated assembly line - it needs human interven- tion. Furthermore, it is believed, that it could not be expected from the modern ham to manually tune a preselector because it is a lack of comfort. So, how are receivers designed nowadays? Preselection - if present in any serious way - is done by means of octave-band-bass filters or something similar, which worst case may be tuned by varac- tor diodes (inherent nonlinear devices). The large signal behaviour of such a receiver is then tried to be optimized by running the preamp and the mixer at high bias currents and with high LO-levels (+20 dBm LO-level or so is nothing exotic in some of todays gear that claims to have high IP values - with the same 100 mW one could build a nice QRP transmitter). If the equipment is battery operated, this consequently contributes to power consumption. I own a SPR-4, which has a total power consumption of less than 2.5W at 12V DC, and more than half of this power is consumed by the dial-light bulbs (which could be turned off by means of a switch). In the moment, i'm in the construction phase of a (modern) kit for a shortwave transceiver, which is respected for it's performance data, yet the transistors of the preamplifier as well as the one for the post mixer amp draw large amounts of collector current (one of them really carries a heat sink) to overcome the large-signal IP-problems due to the lack of a sharply tuned preselector. This transmitter draws around 250 mA at 12V DC in receive - this is appr. 3.25W, and it does not even have power hungry dial-light bulbs! O.k., it's smaller, lightweight, has more fancy knobs to use (and misuse!) and so on - the basic job of a good to excellent shortwave receiver, however, has been performed by the SPR-4 and maybe others (which i do not know from personal experience) much the same way for now more than 30 years very well - a real improvement in technology, isn't it? And this discussion could be endlessly continued - as an example only named the efforts to get the phase noise level of synthesized local oscillators down to a reasonable value - this was not even a matter of discussion in the days of high quality, temperature compensated, L or C tuned free running VFO's, because the spectral purity of the signal of such a (proper constructed) VFO was and is excellent. I'm pretty sure, that if Bob Drake would have lived nowadays (and if the economy and the market of his business would have allowed him to do so), we would have seen some very reasonable and high- quality ham stuff from his company - for sure he would have applied recent technology like double balanced mixers, DSP's etc., but in a down-to-earth way. I'm in no way a uncritically fighter for yesterdays technology - it is only my intention, to sharpen the view for things and techni- ques that have proven to be good and funtional in the past - and maybe to apply those methods with today's abilities in terms of components, materials, techniques etc. So, this was a lot of stuff to read - thanks to all of the Drake gang for the patience to follow my long and detouring thoughts Herbert, DG7MCC Lee Bahr schrieb: "Lee Bahr" <[EMAIL PROTECTED]> made an utterence to the drakelist gang -- I have no interest in the author or his contraption. This is just like the auto inventions that gets you 100 miles per gallon by just in
Re: [drakelist] Interesting
One small comment from my side: As the article notes, the "...antenna melted while increasing power up to 100 watts". To melt something, there is a need for substantial power to do so, or in other words: power dissi- pation in the antenna. This stands in clear contrast to the other statement in that article, that tells us about a miracle- ous "...80 to 100 percent efficiency of the antenna...". So, i would not spend too much hope into this article as long as i have not seen a comprehensive technical documentation including serious near- and far-field measurement data. Herbert, DG7MCC richard radke schrieb: richard radke <[EMAIL PROTECTED]> made an utterence to the drakelist gang -- Yeah, I know what your saying LeeWon't be sending him a check any time soon...But, sometimes "truth is stranger than fiction" hi,hi Rick -- On Behalf of richard radke <[EMAIL PROTECTED]> Submissions: [EMAIL PROTECTED] Unsubscribe: [EMAIL PROTECTED] - unsubscribe drakelist in body Hopelessly Lost: [EMAIL PROTECTED] - help in body of message Zerobeat Web Page: http://www.zerobeat.net Brought to you courtesy of TLCHost.net http://www.tlchost.net/ --
Re: [drakelist] am band
Ok, sounds that i have triggered a discussion that is touching emotions...so, some words to clear up the issue: Of course, i am also a fan of analog transmission (and the well built vintage radios associated with it - otherwise i would not be here), anyhow: technology is progressing, and, hopefully, the advantage in digitizing AM-radio transmission is not only falling into the hands of the money makers (by the way: besides the modula- tor itself it should be possible to also use existing analog AM-transmitters - even the very small and local ones - for di- gital QAM-based transmission modes...so, maybe the financial efforts are not too big...). And, to meet the topic of this forum: i'm currently in the development and design of an IF- downconverter to the digital radio final IF of 12[kHz], that is able to produce a clean signal with constant group delay out of either the 5.645[MHz] or the 50[kHz] IF of the Drake gear, that we all love...anyone interested in the results sooner or later? vy73 de DG7MCC, Herbert Schulz Greg Putrich schrieb: I believe you're correct. According to some searching, IBOC was rolled out to a handful of markets, including Chicago. Here's a link that talks about the Chicago stations a bit. http://antiqueradios.com/forums/Forum5/HTML/001776.html More info on IBOC: http://www.ibiquity.com/ Greg Herbert Schulz said: > I'm not an US-citizen, so my following statement is a wild guess, > anyhow: Maybe this signal is not an interference, but a transmis- > sion of the emerging, new AM-broadcast mode called "DRM" (Digital > Radio Mondiale) which uses QAM32 or QAM64 as a modulation method > and delivers crystal-clear audio, which is close to FM-hifi-qua- > lity - in some cases (at least here in Europe) even in stereo. If > that is a transmission of that kind, i would suggest to listen to > it (a IF-downconverter to a final IF of 12[kHz] and a PC with sound- > blaster and demodulator software is needed) - the audio quality will > for sure surprise anybody. Those transmissions could be easily identi- > fied, because they have sharp bandwith limits: 10[kHz] (+/-5[kHz] at > shortwave and 9[kHz] (+/-4.5[kHz]) at medium wave (AM) and long > wave. > > vy73 de DG7MCC, Herbert Schulz > > > > > > > DAN COTSIRILOS schrieb: > > > Has anyone else in the Chicago area noticed the digital signal on both > > sides of WIND 560? If that is the kind of interference that broadband > > is going to make uh oh Dan > --
Re: [drakelist] am band
I'm not an US-citizen, so my following statement is a wild guess, anyhow: Maybe this signal is not an interference, but a transmis- sion of the emerging, new AM-broadcast mode called "DRM" (Digital Radio Mondiale) which uses QAM32 or QAM64 as a modulation method and delivers crystal-clear audio, which is close to FM-hifi-qua- lity - in some cases (at least here in Europe) even in stereo. If that is a transmission of that kind, i would suggest to listen to it (a IF-downconverter to a final IF of 12[kHz] and a PC with sound- blaster and demodulator software is needed) - the audio quality will for sure surprise anybody. Those transmissions could be easily identi- fied, because they have sharp bandwith limits: 10[kHz] (+/-5[kHz] at shortwave and 9[kHz] (+/-4.5[kHz]) at medium wave (AM) and long wave. vy73 de DG7MCC, Herbert Schulz DAN COTSIRILOS schrieb: Has anyone else in the Chicago area noticed the digital signal on both sides of WIND 560? If that is the kind of interference that broadband is going to make uh oh Dan
Re: R: [drakelist] RIF: S meter to be or not to be
t; > As a final thought, I had thought about changing the S meter circuit > by adding a FET meter drive circuit to actually measure the AGC > voltage itself. Another consideration was to also add a PIC > microcontroller to not only measure the voltage but also correct it > and drive the meter movement and calibrate the thing. > > rob - K2CU > > > >Herbert Schulz <[EMAIL PROTECTED]> wrote: > > >Months ago, i have read in a publication, that "S9" in the US > >corresponds to 50[µV] into 50[Ohms] and that one S-unit is 5[dB]. In > >Europe, "S9" is equal to 100[µV] into 50[Ohms] and one S-unit > >corresponds to 6[dB]. I have to double check, if my remembrance > >according this article is right, but i think so. > > > >Now, assume three cases (let's assume, that the S-meters are > >displaying a perfect log scale, which is almost never the case in > >reality; furthermore let's assume, that Drake's "S9 = 30[µV] into > >50[Ohms]" statement is based on the "5[dB] per S-unit" > >definition): > > > >- S9 = 100[µV] into 50[Ohms] / 6[dB]: S1 then equals to 0.39[µV] > >- S9 = 50[µV] into 50[Ohms] / 5[dB]: S1 then equalt to 0.50[µV] > >- S9 = 30[µV] into 50[Ohms] / 5[dB]: S1 then equals to 0.30[µV] > > > >The manual of my R-4C states a sensivity of better than 0.25[µV] at a > >noise ratio (S+N)/N = 10[dB] in the ham bands and better than > >0.50[µV] at noise ratio (S+N)/N = 10[dB] on other frequencies. > > > >As S1 normally is a indication of the receivers sensivity at its > >noise limit, and this readout should be given at the receivers worst- > >case sensivity value (which is "0.50[µV] on other frequencies" accor- > >ding to the R-4C specification), i would suggest to use the > >US-defini- tion "S9 = 50[µV] into 50[Ohms] at a 5[dB] per S-unit scale" here. > > > >Regards and 73 from > > > > > >Herbert, DG7MCC > > > > > > > > > >mailbox55122 schrieb: > > > >> Hi friends, > >> on the R4C manual is stated that S9 on the S meter means 30 > >> microvolts of RF > signal at the antenna input. It looks that the standard S9 signal are > 100 microvolts of RF signal (on 50 ohm). > >> > >> Where is the true? Or better, what is the real S9 value? > >> > >> 73 > >> de > >> IOKPL, Pietro > >> > >> > >> > >> -- > >> Submissions: [EMAIL PROTECTED] > >> Subscribe: [EMAIL PROTECTED] - subscribe drakelist in body > >> Unsubscribe: [EMAIL PROTECTED] - unsubscribe drakelist in > body > >> Hopelessly Lost: [EMAIL PROTECTED] - help in body of message > >> Brought to you courtesy of TLCHost.net http://www.tlchost.net/ > >> --- > >> --- > > > > __ > Introducing the New Netscape Internet Service. > Only $9.95 a month -- Sign up today at > http://isp.netscape.com/register > > Netscape. Just the Net You Need. > > New! Netscape Toolbar for Internet Explorer Search from anywhere on > the Web and block those annoying pop-ups. > Download now at http://channels.netscape.com/ns/search/install.jsp > -- > Submissions: [EMAIL PROTECTED] > Subscribe: [EMAIL PROTECTED] - subscribe drakelist in body > Unsubscribe: [EMAIL PROTECTED] - unsubscribe drakelist in body > Hopelessly Lost: [EMAIL PROTECTED] - help in body of message > Brought to you courtesy of TLCHost.net http://www.tlchost.net/ > -- -- Submissions: [EMAIL PROTECTED] Subscribe: [EMAIL PROTECTED] - subscribe drakelist in body Unsubscribe: [EMAIL PROTECTED] - unsubscribe drakelist in body Hopelessly Lost: [EMAIL PROTECTED] - help in body of message Brought to you courtesy of TLCHost.net http://www.tlchost.net/ -- -- Submissions: [EMAIL PROTECTED] Subscribe: [EMAIL PROTECTED] - subscribe drakelist in body Unsubscribe: [EMAIL PROTECTED] - unsubscribe drakelist in body Hopelessly Lost: [EMAIL PROTECTED] - help in body of message Brought to you courtesy of TLCHost.net http://www.tlchost.net/ --
Re: [drakelist] Cleaner for Equipment
Richard, in case you can and will disassemble the front panel totally from the rest of the chassis that way, that you have the single front panel and the knobs available as single part, my experience is: Clean it with a stiff-bristled handbrush in warm to hot water with lot's of soap and lot's of water by heavily brushing it, so that you can obtain lots of soap-foam. If you do that several times with the front panel as well as the knobs, then most of the nikotine-residue will disappear. I have nothing but the best experience with that method, and i applied that to several different equipment (Drake, HP, Rohde & Schwarz, Tektronix etc.). Lots of success in your cleaning action and 73 from Herbert, DG7MCC Richard Holder schrieb: I have just purchased a Drake set of rigs, R-4C, T-4XC, AC-4, MS-4, and FS-4. The transmitter front is relatively clean but the receiver and associated units hae been used by a heavy smoker. There is a considerable difference in color bwteen the front of the receiver and the transmitter. Also the FS-4 shows considerable smode residue on it. What would the best cleaner be? I have used 'Fantastik' with good results on other equipment but how would that affect the plastic on the front of the FS-4. I think it might be a good move to clean all the wafer switches in the RX and FS-4 as it has been used in a smoky environment and has been stored for some years without being used at all. Any suggestions would be appreciated. 73 Dick VE4QK --- Outgoing mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.639 / Virus Database: 408 - Release Date: 3/22/2004
Re: [drakelist] RIF: S meter to be or not to be
Months ago, i have read in a publication, that "S9" in the US corresponds to 50[µV] into 50[Ohms] and that one S-unit is 5[dB]. In Europe, "S9" is equal to 100[µV] into 50[Ohms] and one S-unit corresponds to 6[dB]. I have to double check, if my remembrance according this article is right, but i think so. Now, assume three cases (let's assume, that the S-meters are displaying a perfect log scale, which is almost never the case in reality; furthermore let's assume, that Drake's "S9 = 30[µV] into 50[Ohms]" statement is based on the "5[dB] per S-unit" definition): - S9 = 100[µV] into 50[Ohms] / 6[dB]: S1 then equals to 0.39[µV] - S9 = 50[µV] into 50[Ohms] / 5[dB]: S1 then equalt to 0.50[µV] - S9 = 30[µV] into 50[Ohms] / 5[dB]: S1 then equals to 0.30[µV] The manual of my R-4C states a sensivity of better than 0.25[µV] at a noise ratio (S+N)/N = 10[dB] in the ham bands and better than 0.50[µV] at noise ratio (S+N)/N = 10[dB] on other frequencies. As S1 normally is a indication of the receivers sensivity at its noise limit, and this readout should be given at the receivers worst- case sensivity value (which is "0.50[µV] on other frequencies" accor- ding to the R-4C specification), i would suggest to use the US-defini- tion "S9 = 50[µV] into 50[Ohms] at a 5[dB] per S-unit scale" here. Regards and 73 from Herbert, DG7MCC mailbox55122 schrieb: Hi friends, on the R4C manual is stated that S9 on the S meter means 30 microvolts of RF signal at the antenna input. It looks that the standard S9 signal are 100 microvolts of RF signal (on 50 ohm). Where is the true? Or better, what is the real S9 value? 73 de IOKPL, Pietro -- Submissions: [EMAIL PROTECTED] Subscribe: [EMAIL PROTECTED] - subscribe drakelist in body Unsubscribe: [EMAIL PROTECTED] - unsubscribe drakelist in body Hopelessly Lost: [EMAIL PROTECTED] - help in body of message Brought to you courtesy of TLCHost.net http://www.tlchost.net/ --
[drakelist] email-blockers / spam
Hi to everyone on the list, i do not like to write this, however: As it appears now, internet robots have detected my companies internet domain (where i'm running my emails from) and are using general, public known email-adresses from this domain (like: [EMAIL PROTECTED] or [EMAIL PROTECTED]) for distribution of spam (and, possibly, maybe viruses) by faking the sender email adress. Clear statement: I or my company have NOTHING to do with the distribution of any type of this malware. Furthermore (even while not being the origin of that annoyance in any case) i want to apologize for any inconvenience, that may arise or may have arosen out of this criminal misuse of our internet domain. This fact came to my knowledge due to the simple fact, that a ever increasing number of mail servers are declining my emails with the error message "black list - we do not accept spam" or a refuse message similar to that. This seems to be mainly the case with mail- servers located in the US, as i can see now. So, if anybody on this list is expecting answers, comments, respon- ses or whatever from me, that she or he has not received yet, please email me again, then i will respond from another email account. And, please do me an additional favour: If possible, please inform your email provider, that we (the domain listed in the "sender" or "from" header-section of this email) do not distribute any spam mail or viruses on our own - our internet-domain simply became and becomes misused in a criminal way from somebody, that i / we do not know and that is uncontrollable by us / me. If possible, it would be nice, if the email provider could remove our domain from the blacklist. This should not elevate the level of danger, as all major email providers (to my knowledge) are running up-to-date virus-checkers. Thanks for your patience and understanding in reading this lines. Kind regards and vy73 Herbert Schulz, DG7MCC
[drakelist] email-blockers / spam
Hi to everyone on the list, i do not like to write this, however: As it appears now, internet robots have detected my companies internet domain (where i'm running my emails from) and are using general, public known email-adresses from this domain (like: [EMAIL PROTECTED] or [EMAIL PROTECTED]) for distribution of spam (and, possibly, maybe viruses) by faking the sender email adress. Clear statement: I or my company have NOTHING to do with the distribution of any type of this malware. Furthermore (even while not being the origin of that annoyance in any case) i want to apologize for any inconvenience, that may arise or may have arosen out of this criminal misuse of our internet domain. This fact came to my knowledge due to the simple fact, that a ever increasing number of mail servers are declining my emails with the error message "black list - we do not accept spam" or a refuse message similar to that. This seems to be mainly the case with mail- servers located in the US, as i can see now. So, if anybody on this list is expecting answers, comments, respon- ses or whatever from me, that she or he has not received yet, please email me again, then i will respond from another email account. And, please do me an additional favour: If possible, please inform your email provider, that we (the domain listed in the "sender" or "from" header-section of this email) do not distribute any spam mail or viruses on our own - our internet-domain simply became and becomes misused in a criminal way from somebody, that i / we do not know and that is uncontrollable by us / me. If possible, it would be nice, if the email provider could remove our domain from the blacklist. This should not elevate the level of danger, as all major email providers (to my knowledge) are running up-to-date virus-checkers. Thanks for your patience and understanding in reading this lines. Kind regards and vy73 Herbert Schulz, DG7MCC
Re: [drakelist] Filter Cap on Drake R4A
Peter, i do not own a R-4A, but i may have some practical comments: 1.) A large ripple voltage combined with excessive trans- former heating may also point to an overload condition, not necessarly may it only be one or more failed cap's. So, before doing any repair, i would suggest to look for that first. The voltage chart usually stated in Drake's manuals could be of some help here. 2.) It may also be, that one of the two rectifying diodes has failed. This could also lead to transformer heating (dependent on the type of diode failure). Anyhow, in that case the ripple should be asymmetric in the appearance of the waveshape with respect to the positive and negative portion of the mains-sine-waveshape. In that case i would suggest to replace both diodes against 1N4007's. 3.) A ripple voltage in the range of several [Vpp] seems to be normal direct at the rectifier and the first cap. The ripple voltage of more interest would be the one on the final HV-DC-supply line. In my R-4C, this ripple vol- tage on the +150[V] line is very significantly below 1[Vpp]. I do not know, how the power-supply of the R-4A is made up, but i assume, that there are not too much differences. 4.) As long as one of the cap's has no short circuit (which is usually not the case, they simply dry out), the cap's should not be the reason for your power-transformer to heat more than normal. Maybe this "more than normal" heating has another reason? 5.) If the cap's only have low capacity and no shorts, i would recommend to parallel them on the bottom of the chassis with the approbriate capacity values. 100[uf] 250[V]DC are really small capacitors today compared to the time the R-4A was built. And a 22[uF]/25[V] cap may be so small nowadays, that it may be hard to see. In this way you do not tamper with the origi- nal state of the receiver in a irreversible way. I did exactly this type of repair with my SPR-4. 6.) As dried-out electrolytics also may exhibit contact pro- blems between the foil and its associated electrode connection to the outside world, i would suggest to parallel each paralleled electrolytic named under topic 2.) with an 0.1[uF] ceramic capacitor with approbriate voltage rating. The reason for this is to supress any possible contact noise of this dried-out-electrolytics at the source by shorting it to ground. The new, paral- lelled electrolytics can not do this job because they exhibit significant ESR (equivalent series resistance) at higher frequencies which they have not been made for. 7.) In case of space problems, i would not see it as a pro- blem, to place the new, paralleled electrolytics at a place under the chassis, where it is approbriate and where the corresponding DC-wiring is runing to. At least in my R-4C the +150[V] DC wiring is distributed nearly all over the bottom of the chassis, so that it should be possible to find an comfortable mounting place. Due to the small currents, that are drawn from the HV-DC-supplies, i would not expect the wiring resistances to generate any serious problem. Much success in repairing your R-4A, kind regards and 73 Herbert, DG7MCC Peter Hoon schrieb: R4A: It appears that one or more sections of the Sangamo power supply filter cap are defective, since I measure 5.2 volts p - p with a scope at the junction of diodes D4 and D5 (156 VDC). And my power transformer gets very hot. The cap is in a single aluminum Sangamo chassis mount with: 100 MFD 200 VDC 100 MFD 200 VDC 100 MFD 200 VDC 20 MFD 20 VDC 1) Anyone have a spare from an R4A they are parting out? 2) Suggestions for a source for this filter cap from others who have gone before me. 3) Have improvisors found discrete caps from a source (pse recommend one), left the chassis mount unit alone, and mounted these discrete caps under the chassis? 4) Has anyone actually drilled out this filter cap shell, and mounted discrete components inside? Any other ideas or comments appreciated. Peter, VE1CHS -- Submissions: [EMAIL PROTECTED] Subscribe: [EMAIL PROTECTED] - subscribe drakelist in body Unsubscribe: [EMAIL PROTECTED] - unsubscribe drakelist in body Hopelessly Lost: [EMAIL PROTECTED] - help in body of message Brought to you courtesy of TLCHost.net http://www.tlchost.net/ --
[drakelist] FS-4, Contact Cleaners, Bulbs & Knobs for the 4-Line
Hello to all of the list, the following text is a little bit longer then usual and therefore it may be some lines to read, but as i had some requests to hold my FS-4 related comments public rather that private, i will do so. For the readers that are uninterested in the one or other topic, i apologize in advance for stressing your patience - in no way it's my intention to be annoying or intrusive. First, thanks to the various comments on the contact cleaner, it de- finitely will try to get DeOxit in England. My personal experiences with some products from the former "Kontakt Chemie" company are not the best in professional circuits. Especially equipment treated with "Kontakt 60" showed the trend to reappear with exactly the same pro- blems appr. half a year after the cleaning. "Tuner 600" worked a little better with this respect, but also not 100% satisfying. I cleary have to point out, that my personal experience with this two products is now laying years behind - and in the meantime the com- pany may have changed the receipe of this products significantly without changing the name. My best experience with contact cleaners in the past has been the product "Rivolta SLX1000" from a company named "Bremer & Leguil", but due to more stringent environmental regulations in Europe, this product no longer is on the market, and the successor of this product by far does not match the per- formance of "SLX1000" for RF and other electronics stuff. So, if you should have the one or other can from "SLX1000", keep them like gold. To my knowledge, this also in the past was the pre- ferred product by a bunch of professional companies like R&S, amongst others - and the usually select very careful, what they use. In Germany, there is another product available, which looks very promising and which will undergo a detailed test by me, if it finally will arrive here (i have ordered five cans). The name of this product is "EML200F" from "Electrolube". If of any interest, i will post the results of my tests here in this forum - please let me know. In Germany this contact cleaner (it is labeled to be a "con- tact cleaning oil") is sold by the company "Rainer-Förtig Elektronik". A 200[ml] can goes for EUR 7,95. The link to their homepage is (you have to scroll down to the bottom of this page): http://www.rainer-foertig.de/Bastler-Geraete.htm Please note, that i do not have any affiliations nor do i have any other commercial interest in / with the companies i mentioned above. I just wanted to make live easier for the readers of this lines by providing "where to get" information. The same statements goes also for the companies that i am naming below in the FS-4 section. So, now for some FS-4 comments: First of all, it may be a tricky job, to obtain some of the semicon- ductor parts for this synthesizer. So, i will do some comments on the individual parts: - MC1733 (U1): Obsolete part from former "Motorola Semiconductor", now "ON semiconductor". This is a 200[MHz] differential amplifier with some selectable, fixed gain settings. If of any interest, i can scan the datasheet and dis- tribute it as a PDF-file. This part may be obtained from "Rochester Electronics" (www.rocelec.com), where ONSemi / Motorola states that they would be their official source for obsolete parts. The location of this IC is on the "A100 VCO-Board" - MC4044 (U2): Obsolete part from former "Motorola Semiconductor", now "ON semiconductor". This is the phase detector for the PLL. If of any interest, i can scan the datasheet and dis- tribute it as a PDF-file. A 1:1 drop-in-replacement is the MC4344, which, however, is also obsolete. This part may be obtained from "Rochester Electronics" (www.rocelec.com), where ONSemi / Motorola states that they would be their official source for obsolete parts. A reason for this chip to die may be a minor design flaw of the FS-4: The pins 5 and 10 of this chip are tied together without any current limiting resistors which is in clear contrast to the Motorola application note "AN535" (although this apps-note is using a MC4344). Thus, these both ouputs may "fight" against each other, possibly resulting in substantial short circuit currents at this point. A suggested cure here will be: - open the connection between pin 5 and 10 of this IC. - leave R319 (8.2[K]) connected to pin 5. - connect an additional resistor with 8.2[K] to pin 10 and the other end of that resistor to the base of Q303 (2N3392). All this stuff is located on the "A300 Digital Board" Pleas
Re: [drakelist] FS-4
Good morning, Gene, you are absolutely right, this is the point to start with. In my previous answer, i just assumed without naming it ex- plicitely, that all the obvious checks and repairs for equipment of that maturity still have been performed - namely such things like contact cleaning, looking for and fixing any broken wires, faulty connectors etc., as this kind of stuff by experience generally makes up to 50% or more of typical equipment faults. Keyword DeOxit: As this appears to be a close-to-miracle con- tact cleaner according to all the reports, i'm looking to ob- tain some spray cans etc. of this particular brand. Does any- body know, where in Germany or in Europe i can get some of them (as far is i know, DeOxit will not ship to end users in Europe because of the danger for the air transport, that the explosivity of that material exhibits). Thanks a lot for all of your comments. Best regards Herbert, DG7MCC Gene McCalmont schrieb: Hello Dan; I have had problems with my FS-4 that were similar to the symptoms you describe and the repair was rather simple, which may (or may not) mirror your situation. The FS-4 uses wafer switches similar to those found in our other classic Drake rigs. Over the years, these wafer switches build up oxidation which interferes with the switch's operation. Before I would try any advanced diagnostic/repair techniques as offered by Herbert Schulz, I suggest you clean the wafer switches with DeXoit and see if this clears up your problem. Disassembling the FS-4 is rather easy and all of the components are readily accessible. Be sure to remove the top inner shield to gain access to the wafer switches under the shield. I use DeXoit D-100 in the small dispenser bottle rather than the spray can, so that I can concentrate the cleaner on the switch contacts rather than spray down the whole assembly. If this does not solve your problem, I personally would appreciate you and Herbert posting your discovery and repair techniques to the reflector rather than go private. We can all benefit from Herbert's considerable expertise in this matter. Best regards; Gene W5DDW Gene McCalmont 270 Oakridge Road Argyle Texas 76226 -Original Message- Does anyone have any experience with fixing a FS-4? I have one that puts out erratic freq.'s and the 0-5 does not change anything. Any ideas? Dan -- Submissions: [EMAIL PROTECTED] Subscribe: [EMAIL PROTECTED] - subscribe drakelist in body Unsubscribe: [EMAIL PROTECTED] - unsubscribe drakelist in body Hopelessly Lost: [EMAIL PROTECTED] - help in body of message Brought to you courtesy of TLCHost.net http://www.tlchost.net/ --
[drakelist] Re: FS-4 Synthesizer
This email is for: DAN COTSIRILOS" <[EMAIL PROTECTED]> Dan, as i got the below respond from your email provider (for whatever reason, i do not know - i use a serious german email account powered by an t-online server, which is not suspected to distribute junk or spam-mail), i post my answer back to you on this public platform - if you want to go private, please give me an email adress that works without such annoying refusement messages). The original message was received at Wed, 10 Mar 2004 22:27:27 +0100 (MET) from pD9E95A31.dip.t-dialin.net [217.233.90.49] - The following addresses had permanent fatal errors - <[EMAIL PROTECTED]> (reason: 550-81.169.145.165 blocked by blacklist.mail.ops.worldnet.att.net.) - Transcript of session follows - ... while talking to gateway2.worldnet.att.net.: >>> MAIL From:<[EMAIL PROTECTED]> SIZE=9009 BODY=8BITMIME <<< 550-81.169.145.165 blocked by blacklist.mail.ops.worldnet.att.net. <<< 550 Blocked for abuse. Please contact the administrator of your ISP or sending mail service. 554 5.0.0 Service unavailable Reporting-MTA: dns; post.webmailer.de Received-From-MTA: DNS; pD9E95A31.dip.t-dialin.net Arrival-Date: Wed, 10 Mar 2004 22:27:27 +0100 (MET) Final-Recipient: RFC822; [EMAIL PROTECTED] Action: failed Status: 5.0.0 Diagnostic-Code: SMTP; 550-81.169.145.165 blocked by blacklist.mail.ops.worldnet.att.net. Last-Attempt-Date: Wed, 10 Mar 2004 22:27:29 +0100 (MET) Betreff: Re: [drakelist] FS-4 Datum: Wed, 10 Mar 2004 22:26:49 +0100 Von: Herbert Schulz <[EMAIL PROTECTED]> An: DAN COTSIRILOS <[EMAIL PROTECTED]> Referenzen: 1 Dan, for first, there is a question: are you well eqipped with measure- ment tools for fixing that problem? It is likely, that you need some advanced measurement rig's - the minumum i would recommend is an analog scope with a MINIMUM bandwith of 150[MHz] (like vin- tage Tektronix or HP scopes) with approbriate, high frequency and low capacity 10:1 probes as well as a reliable, accurate frequency counter with a minimum of 80[Mhz] measurement rangethe second point is, that most of the integrated circuit stuff used in the FS-4 is no longer available today, but you may need the one or other chip just for cross checking Now, for the details: - Is the +5[V] and +12[V] DC supply really stable with no more than appr. 50...100[mVpp] max. ripple and noise? - Can you measure a stable sine-wave signal of 9.600[MHz] on test- point "A" (testpoint "A" is the junction between R416 (470[Ohm]) and C418(0.001[µF])? What is the amplitude (pk-pk) of that signal? You have to measure it with a 10:1 probe with no more than appr. 5[pF] load capacity. This measurement should be independent of any switch setting. - Can you measure a stable sine wave signal of 5.000[MHz] at the junction of C301 and C302? Or, as an alternative, measure this signal at the base of Q302 (2N3563). This signal should be in the range of several ten's to hundred's [mVpp]. However, please note, that capacitive loading of the probe is even more critical at that points, so that i would recommend a probe with a capa- citive load of no more then appr. 2[pf]. This measurement also should be independent of any switch setting. This measurement point is located on the "A300 digital board". - What does the input signal of U1(SN7490) at pin 1 look alike? Ideally, it should be a waveform shape that at low goes well beyond appr. 700[mV] and where the high exceeds significantly over appr. 2.4[V]. Also here, measure with a very low capacity probe and a SHORT ground lead, otherwise you will see ringing and other "hard to read" effects in the signal. This measurement also should be independent of any switch setting. This measurement point is also located on the "A300 digital board". - Does the output signal of U1(SN7490) - a 10:1 frequency divider - present a true TTL-square-wave-signal (1:1 duty cycle) with a frequency of 500.00[kHz] and a amplitude low of 400[mV] maximum as well as a amplitude high of 2.8[V] minimum? Again, also here a low capacitance probe as well as a short ground lead is man- datory. Also here, this is a measurement that is independent of any switch setting. As well as the above, also this measurement point is located on the "A300 digital board". - What is the voltage on the collector of Q202 (2N3563) are looking alike in terms of frequency and amplitude? THIS IS A CRITICAL POINT TO MEASURE IN TERMS OF LOADING THROUGH THE PROBE! This measurement point is located on the "A200 Locked Oscillator Board". These are the tests for the moment. We will go one step further if these tests are in all details prove to be o.k. Kind regards and enjoy your evening as well as 73 Herbert, DG7MCC
[drakelist] R4-C and SPR-4
This eMail is for: Paul Rubin, N8NOV Houston, TX Paul, could you please give me an email adress, where i can send my responses regarding this project to. If i respond to the email-adress that you sent me your email from, the email-server refuses to take my reply because of some sort of "blocking"-mechanism (it appears, as this mailserver is thinking that i'm sending spam, which is not the case). Thanks for your efforts. Kind regards and 73 Herbert Schulz, DG7MCC
[drakelist] R-4C and SPR-4
Hi to all of the list, i'm in the moment in the phase of refurbishing some of Drake's 4-line equipment, actually it's an R-4C and SPR-4. A part of this private project will be to equip these receivers with modifications, that will be done in a way, that does the minimum possible change to the original state of these receivers. The planning incorporates the following: - Buffered output of the premixer into a 50[Ohm] jack in order to connect a external digital frequency coun- ter (which is already commercially available from a third party for a very affordable amount of money). - Buffered output of the final IF (50[kHz]) into a 50[Ohm] jack. The purpose for this is to run this IF output to an external mixer, which does a final downconversion to the 10...18[kHz] freqquency range. - Design of this external mixer, that does this final downconversion from 50[kHz] to 10...18[kHz]. The pur- pose of this mixer is to provide a signal for a power- ful filter/demodulator software (for AM/SSB/CW), that is DSP-based (it uses the DSP that is already present on PC-based soundblasters). This (Windows-based) soft- ware) is already present for download at the internet free of charge for HAM's and noncommercial use. - An extensive (PDF) documentation including images, sche- matics and measurement results for all the refurbishing/ repair/restauration/alignment work done to these two re- ceivers. In order to plan the efforts and grade of professionalism i will incorporate into this, i kindly ask the list members, if this may be of any interest for you. In case of suffi- cient interest, i will do a set of universal usable printed- circuit boards including extensive documentation, which will be available for a nominal fee that covers my cost-of-goods. The planned timeline for the availability of all results in- cluding bare printed-circuit-boards and documentation will be appr. 6 months from now on. So, if anyone is interested in also duplicating this stuff or in any other participation, please let me know. Kind regards and vy73 Herbert Schulz DG7MCC
[drakelist] R4-C versus SPR-4 crystal frequencies and others
Hi all, i may have a silly question, but even reading the manuals carefully several times, i have not been able to find out what i'm asking for now: I'm owning an R4-C and an SPR-4 as well. Both appear to have exactly the same frequency scheme up to the 1st IF-frequency (PTO tuning range 4955[kHz] to 5455[kHz], 1st-IF frequency 5645[kHz]). For me that leads to the assumption, that the crys- tal frequencies for the premixer-xtal-oscillator for the various bands should be absolutely identical in both receivers. However, in reality, the crystal frequencies in the SPR-4 appear to have a -10[kHz] offset with respect to the R4-C (i.e. for 80[m], the XTAL in the R4-C is a 14.600[MHz] type and in the SPR-4 it's a 14.590[MHz] type). Does anybody know, where this -10[kHz] offset results from? Has anybody experience in intermixing the xtal's (of course, after placing them on socket adapters for HC6/U <> HC18/U) for both of these receiver types? Furthermore i ask, if anybody has done the majority or all modifications on an R4-C as documented by VE3EFJ and is willing to tell me about the experiences? I want to par- ticipate from any experience before starting this big mo- dification project, as my R4-C actually is in an absolutely unmodified, original condition. Additionally, i'm looking for some parts to buy: - SPR-4: crystal calibrator, model SCC-4. - SPR-4: transceive adapter, model TA-4. - R4-C: 8-pole-crystal filter for AM, frequency 5645[kHz] (may be of the same type as for the R7/R7A, but i don't know that for sure). - MS-4 speaker in mint condition. - FS-4 frequency synthesizer. If somebody has something to offer, please let me know (if possible, including the approximate estimated shipping charges to Germany). Latest: Does anybody know, if there is a GOOD (i.e. low phase noise) DDS-based frequency synthesizer for the R4-C/SPR-4 etc. on the market? I'm looking either for a well documented sche- matic, or a kit, or a affordable ready-to-use unit. The only thing i found regarding this item is a japanese home page, but besides the schematic and the photo's, i - obviously - did not unterstand one word. This was a lot of stuff - thank you all for your attention and patience. Thanks in advance for all your answers and respon- ses and the associated efforts. vy73, DG7MCC Herbert
[drakelist] R4-C versus SPR-4 crystal frequencies and others
Hi all, i may have a silly question, but even reading the manuals carefully several times, i have not been able to find out what i'm asking for now: I'm owning an R4-C and an SPR-4 as well. Both appear to have exactly the same frequency scheme up to the 1st IF-frequency (PTO tuning range 4955[kHz] to 5455[kHz], 1st-IF frequency 5645[kHz]). For me that leads to the assumption, that the crys- tal frequencies for the premixer-xtal-oscillator for the various bands should be absolutely identical in both receivers. However, in reality, the crystal frequencies in the SPR-4 appear to have a -10[kHz] offset with respect to the R4-C (i.e. for 80[m], the XTAL in the R4-C is a 14.600[MHz] type and in the SPR-4 it's a 14.590[MHz] type). Does anybody know, where this -10[kHz] offset results from? Has anybody experience in intermixing the xtal's (of course, after placing them on socket adapters for HC6/U <> HC18/U) for both of these receiver types? Furthermore i ask, if anybody has done the majority or all modifications on an R4-C as documented by VE3EFJ and is willing to tell me about the experiences? I want to par- ticipate from any experience before starting this big mo- dification project, as my R4-C actually is in an absolutely unmodified, original condition. Additionally, i'm looking for some parts to buy: - SPR-4: crystal calibrator, model SCC-4. - SPR-4: transceive adapter, model TA-4. - R4-C: 8-pole-crystal filter for AM, frequency 5645[kHz] (may be of the same type as for the R7/R7A, but i don't know that for sure). - MS-4 speaker in mint condition. - FS-4 frequency synthesizer. If somebody has something to offer, please let me know (if possible, including the approximate estimated shipping charges to Germany). Latest: Does anybody know, if there is a GOOD (i.e. low phase noise) DDS-based frequency synthesizer for the R4-C/SPR-4 etc. on the market? I'm looking either for a well documented sche- matic, or a kit, or a affordable ready-to-use unit. The only thing i found regarding this item is a japanese home page, but besides the schematic and the photo's, i - obviously - did not unterstand one word. This was a lot of stuff - thank you all for your attention and patience. Thanks in advance for all your answers and respon- ses and the associated efforts. vy73, DG7MCC Herbert
