Re: [Drakelist] 6HS6 Tube
On Jan 1, 2012, at 5:06 PM, Eddy Swynar wrote: Hi Garey, Yes, a VERY good point, indeed! Thanks for adding that "PS"... It never ceases to amaze me, whenever I'm looking for possible "subs" in my books like that here, at just how many tubes seem to be so very much alike---yet they have different numbers. You have to really examine their individual specs closely, & then act accordingly, dependent upon your specific application of the substitute tube... That's because most people don't understand the base concepts behind vacuum tube numbers. RCA for example would sell a specific tube for a function and use it in their radios and TV sets. GE would make a similar tube to do the same thing in theirs with a different model number. The same with Zenith and so on. European and Japanese manufacturers used different model numbers and numbering standards, but in the US, the substitution guides did not show them as they were not available anyway. TV repair people carried around, and stores, such as drug stores, etc, had tube testers and substitution guides. The testers were very simple, if the tube would heat up and conduct electrons it was good and if it did not it was bad. Some testers had neon lamps that would glow when the tube was "shorted", and most had meters, but neither were of much use. Many short circuit conditions did not light the lights and drug store testers were eventually set to show that a brand new tube of the manufacturer sold by that store showed good and all others showed "possibly bad" or bad. For normal use, in a radio or TV set, you could substitute a tube of similar kind from the same manufacturer or a different number from a different manufacturer and it would work. Maybe not as well, but most people had no idea of what was going on inside their TV or radio and as long as there was a picture on the screen and sound from the speaker, no one really cared. There were a few years when I was in high school I made pocket money by replacing tubes in TV sets and radios. The easy way was to look for tubes that did not glow, or were not warm and replace them. All you needed was a 1/4 inch nut driver and a "cheater cord". Then I went to the drug store and bought a new tube. The difficult ones required me to got to Lafayette or Radio Shack. Drake on the other hand did not make tubes and therefore did not make their radios to fit their tubes, they bought tubes to fit their radios. Therefore they actually did engineering to design their radios (instead of combining sample circuits from manufacturers) and in some cases need an exact replacement or changes to the circuit for a different tube, and some adjustment when using a new tube of the same model and manufacturer. They also "pushed the envelope" in tube usage, using them for things that happened to work, but they were not intended. I doubt that anyone who designed a TV sweep tube designed them to function as a high power 30mHz amplifier, but Drake (and others) found one that did. After all, from the point of view of building a radio using a tube designed for RF amplification there was the 807 and the 6146. I'm not sure of the dates, but I think that the 807 was first available in the the 1930's and the 6146 in the 1940's. It's just that TV sweep tubes, no matter how mistreated or misused they would be, were cheap and available in almost any drugstore, supermarket, hardware and department store and cheap. Geoff. -- Geoffrey S. Mendelson, N3OWJ/4X1GM My high blood pressure medicine reduces my midichlorian count. :-( ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] TX-4C 160 Mod ?
On Dec 21, 2011, at 12:26 PM, Ron wrote: I sold my incomplete set of HR mags when I purchased the entire PDF collection. The PDF of the page that the dial is on is not that great. OTOH you might be able to use it for a starting point to do image restoration and enhancement. Which set do you have? There are two "out there". The first set was produced by a ham on his own. It was sold as a set of two DVD-ROMs. I don't know his motivation, but based upon the price he charged I think he was trying to preserve a dying art. I don't think he understood that HR magazine did not simply cease to exist, they stopped publishing magazines and sold the rights to what they had published. Later the holder of the copyrights, CQ magazine, produced an official set on CD. The quality of the images from the other set was much better. Geoff. -- Geoffrey S. Mendelson, N3OWJ/4X1GM My high blood pressure medicine reduces my midichlorian count. :-( ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] TX-4C 160 Mod ?
On Dec 21, 2011, at 8:15 AM, Jim Shorney wrote: Cord marker, as on the interconnect cables for the twins? I don't know if he can do anything that small. His company started out doing traffic signs and stuff. I have a Brother P-Touch label maker. This is a small handheld device that prints stick on labels on 1/2 inch wide tape. The labels come in various colors and backgrounds. Brother also sells a USB printer that takes the same tape, anyone have one? I wonder if you can use it to print graphics instead of text. Then you could print scanned images of small tags, etc. Geoff. -- Geoffrey S. Mendelson, N3OWJ/4X1GM My high blood pressure medicine reduces my midichlorian count. :-( ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] dangerous spam maessages???
On Nov 28, 2011, at 11:01 PM, sebdesnCC wrote: Tom, I got one as well, It had a drakelist address on it but fortunately Norton got it and put it in the spam folder,How does it get the drakelist address on it and then to the list??, sorry if that is a dumb question… The infected computer sends emails to anyone the person has ever received an email from, and it uses random names from the list as the person the email is from. The list is not moderated (as in every post is read BEFORE it is posted), the email is checked to see if it comes from a registered user's email address and is posted. Because the infected computer has a list of everyone who ever posted an email to this list that was received by it, it is possible for the email sent to the list be from a randomly chosen list member and it gets through with an innocent bystander being blamed for it. Geoff. -- Geoffrey S. Mendelson, N3OWJ/4X1GM My high blood pressure medicine reduces my midichlorian count. :-( ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] I've got a job ahead of me.
On Nov 23, 2011, at 7:47 PM, Steve Wedge wrote: TNX to all for responding - this is my first SPR-4, so all comments are welcome! Here's the actual quote, from page 19 of the manual: "CARE SHOULD BE TAKEN NOT TO DISTURB THE LEAD DRESS IN THE SPR-4 SINCE THIS. IS CRITICAL IN SEVERAL CIRCUITS." Geoff. -- Geoffrey S. Mendelson, N3OWJ/4X1GM My high blood pressure medicine reduces my midichlorian count. :-( ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] I've got a job ahead of me.
On Nov 23, 2011, at 7:47 PM, Steve Wedge wrote: My first scan of this board has revealed to me that much of it is the power supply for the entire receiver. I'm wondering just how much ALC circuitry is on the same board. If many of those 18 or so 26 AWG wires are just powering other small boards, their connection locations may be less critical. Again, I'll have to rack my brains a bit on the drawings to figure out where all the wires go. Before you do anything, take a lot of pictures. There is a comment buried in the manual (I'm paraphrasing from memory) that the way the wires are run affects performance. I have an SPR-4. It's one of the best sounding AM shortwave receivers I've ever owned. I hate the ergonomics, but one can put up with them for the performance. Geoff. -- Geoffrey S. Mendelson, N3OWJ/4X1GM My high blood pressure medicine reduces my midichlorian count. :-( ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
[Drakelist] Radios for sale in Israel
I'm selling the following radios in ISRAEL. It is impossible to for me to ship them, so before you make an offer on them, you need to arrange for someone to collect them in Jerusalem and ship them to you. Payment is in cash/paypal when picked up. The radios are in good condition but may need to be dusted off and used to achieve their full potential. Prices are in "new" Israeli shequels. Current rate is one shequel is $0.27 (twenty seven cents). Geoff. Drake TR-5 with CW filter. Matching power supply (230/120 volt) RV-75 (digital, very rare) 8,000 NIS. Drake SPR-4 recevier, needs repair, extra crystals. Includes noise blanker and calibrator (extras) 800 NIS. License not required. -- Geoffrey S. Mendelson, N3OWJ/4X1GM My high blood pressure medicine reduces my midichlorian count. :-( ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] R-4b
On Oct 30, 2011, at 12:53 AM, Ron Ries wrote: 3) Last question: With RF gain fully CW on the R4B the ambient (no signal) noise level is 3-4 S units above where the TS-850 and TS-480 indicate the noise level is for the same antenna system (trap dipole up 27') and RF gain full on. Is this an indication that tube radios have a higher sensitivity to atmospheric noise? With the RF gain fully CCW the indicated noise level on the R4B is comparable to the newer radios with RF gain full on. Not sure what to make of this. Between the time Kenwood made the TS-430 and the TS-450, the Japanese standard for S meter readings changed. Assume that the Drake was calibrated to a different standard. Geoff. -- Geoffrey S. Mendelson, N3OWJ/4X1GM My high blood pressure medicine reduces my midichlorian count. :-( ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] Watch those ball bearings!
On Oct 23, 2011, at 7:46 PM, Steve Wedge wrote:
I was quite fortunate, Evan, in that I was working over the granite
countertop of my kitchen island. I heard them hit and knew
immediately (after issuing a few expletives). I'm lucky they didn't
go bouncing and then rolling onto the floor. I honestly wasn't
expecting them to come out at all.
Many years ago I apprenticed for 6 months in the camera repair
business. We used sheets of wet suit material, inside side up to cover
our work surfaces. You can get scraps cheaply at dive shops that make
custom wet suits and cut them to fit.
Little parts don't bounce on them. They bounce on the outer side, so
make sure you've got the right one up. :-) ("green side up, green side
up, green side up")
A small magnet is good to pick up those steel parts that fall and are
missed.
Geoff.
--
Geoffrey S. Mendelson, N3OWJ/4X1GM
My high blood pressure medicine reduces my midichlorian count. :-(
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[Drakelist] Fwd: Re Diversity Reception
On Aug 8, 2011, at 8:58 AM, John Brown wrote: Probably need two antennas, two receivers and a multiplexer that can switch between either receiver as the signal on each antenna fades in and out. It was called "Diversity Reception" and was used for commercial RRTY (among others uses)in order to maintain a constant signal feed to the RTTY machines. The 2 antennas that were typically used were 4 acre Rhombics or similar, so they were spread out over a relatively broad area of land able to react to the ionospheric changes causing the fading. Don't see how you can do it with just two antennas without having them reasonably separated and some way of detecting the change in signal strength to select the appropriate antenna. It was also used during WWII in Europe to hear the BBC over jamming. The jamming signals varied in strength and noise from band to band, so it was popular when they had them to use two receivers each on a different frequency near each side of the head. The stereo effect put the jammers off to the sides and the main signal in the middle, reducing the effect of the jammers. You can do something similar with modern receivers on the ham bands by using a computer controlled set of receivers each with a different antenna. For example if you use a computer controlled transceiver as you tune it, the computer monitors the frequency and adjusts the secondary receiver as needed. Then you listen to the two receivers with stereo headphones one with each ear. I don't know much about them, but one of the more famous tube receivers used by the US military could be modifed for diversity reception (it may have been a factory mod) combining two of them, but that was for fixed frequency reception, you tuned them both, by hand, to the same "channel". This was probably what John wrote about above. I believe MFJ has some sort of diversity reception antenna, but I know nothing about it other than they sold/sell it. Geoff. -- Geoffrey S. Mendelson, N3OWJ/4X1GM ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] R-4A PTO: It wasn't the transistors (entirely)
Eddy, This does NOT seem right to me, and leads me to suspect---in my case, anyway---that another complete tear-down of the PTO "works" is in my future, to be followed by a THOROUGH cleansing of everything in sight that moves with a wash of isopropyl rubbing alcohol & Q- tips...no guarantees that this'll work, either, of course---but hope springs eternal. On another list, with another brand of radios, some people have had good luck fixing "sticky" (but not stuck) PTOs using a bicylce lubricant. It's not sold where I live, so I did not pay attention to the name, it's something like "tri-flow" (or maybe not). It's a spray lubricant with little bits of teflon in it. Anyone with any experience or knowledge care to comment? Is it a good idea or a bad one? Any success or failures? Geoff. -- Geoffrey S. Mendelson, N3OWJ/4X1GM Making your enemy reliant on software you support is the best revenge. ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] SW Crystals Suggestions for the R-4B?
On Jul 26, 2011, at 9:08 PM, Don Cunningham wrote: I notice that no one has really answered your question. For my listening enjoyment, I like the ranges 5.5 to 6.0, 6.0 to 6.5, 9.0 to 9.5, 9.5 to 10, 11.5 to 12, 15.0 to 15.5 and 17.5 to 18. If that's to many crystals, the grouping around 9 to 12 megs in the evening brings the most international broadcast in. The 6 meg ones are becoming largely "shortwave evangelists", both living and dead, hi. Hope that helps!! Old time shortwave listeners on Drake gear have found a crystal frequency that gives like 5.7 or 5.8 to 500 kc up from that and solved having to have two crystals in the 6 meg range. If I run across mine in a drawer, I'll let you know what they did. Don't forget the 40m band. 7.100-7.200 is still shared with SWBC although most stations have left it. Even when they are gone, 7.300-7.500 will still be heavily used. I agree with Don's suggestions, but here's my take specifed by RECEIVE frequency, not crystal frequency: 1. 7.000-7.500 (should already be in the rig) 2. 11.700-12.200 (although a 11.500-12.000 crystal would probably do) Those would be my choices if I had to get them made. Bry Carling should be able to help you, he has a big stock of crystals, reasonable prices and good service. My second choices would be (in order): 17.500-18.000 6.000-6.500 15.000-15.500 9.000-10.000 (2 crystals) 3.500-4.000 (3.850-4.000 is an SWBC band) Note I am NOT in the US, and propigation, etc is different. Geoff. -- Geoffrey S. Mendelson, N3OWJ/4X1GM Making your enemy reliant on software you support is the best revenge. ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] R4A on an inverter
On Jul 20, 2011, at 7:55 AM, Neil M Califano wrote: The power consumption of the R4a is 60 watts and I'd like to run the radio off my 12 volt car cigarette lighter using a 130 watt PSW inverter. I think the fuse is 10 amps. So 12.5 volts x 10 amps=125 watts. But I heard of fuses blowing running only laptops. It looks good on paper, but practically will this work? Probably not. 1. The inverter is rated 130VA (you can look up the reason why, and what a VA (volt amp) is, but suffice it to say that a 130VA inverter will max out (and possibly go "fizzle pop" without a good fuse or overload protection at 91 watts. That is of course assuming that it's a 130VA inverter in the first place, based on the specs you gave it it's 130VA INPUT. 2. The inverter is barely 50% efficient. If you are lucky, you can run a 65 watt laptop off of it, but probably not. My GUESS is that it's 91 Watts input and 30-40 watts out. 3. The R4a uses 60 Watts (or so) with the volume set at a reasonable level. That's how things were rated in those days. It may draw a little more with a loud station, and often draws less BUT it's a tube radio. Tubes draw lots of current when cold and as they warm up draw a lot less. So if for a short time the tubes draw 100 watts, or 200 watts, or even 300 watts, no fuse will protect your inverter, it will be toast. 4. Inverters are just switching power supplies. They put out lots of noise and so on. The really cheap ones put out square waves instead of smooth sine waves, and you won't be able to hear anything over the noise. Geoff. -- Geoffrey S. Mendelson, N3OWJ/4X1GM Making your enemy reliant on software you support is the best revenge. ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] TR-4 Redux
On Jun 23, 2011, at 12:36 AM, Richard Knoppow wrote: > One other thing, the blue filters in the dials were not the correct gel. > When dimmed the dials became unreadable and were pretty dim even with the > dial lamps at full brightness. I took the filters out and will eventually > replace them with the correct Lee gelatins. > I know it's a matter of taste and correctness, but I have good luck replacing blubs with LED "bulbs". These look like bulbs, and plug into the same sockets. I used a white one and two blue ones in my SPR-4. It probably does not look "right", but I never saw it in the first place, I got it when it was 35 years old. The white bulb is too blue compared to a #47. There is a place in Pennsylvania that sells "warm" white LED bulbs to replace #47s, but they don't ship overseas, so I'll just suffer with what I have. :-) It's slightly off topic, I've also replaced them in TEN-TEC rigs too. My ARGO 509 has an LED bulb illuminating its S-meter and I have LED's waiting to replace the dial lights. If I had them when I restrung the dial cord, I would of replaced them then, but I did not, and I see no need to replace working bulbs, especially when it requires removing the front cover. 73, Geoff. -- Geoffrey S. Mendelson, N3OWJ/4X1GM Making your enemy reliant on software you support is the best revenge. ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] Ten-Tec and Drake Compared
On Jun 19, 2011, at 8:05 PM, rhule...@comcast.net wrote: Dial light for the 509 no longer available from any source. Huh? The dial light is just two grain of wheat bulbs in series that glow a dull red with 12 volts, and slightly brighter on 13.8v. You could replace them with anything including the (relatively) new 180 degree LEDs. The S meter light is just a 12 volt long/life low brightness bulb with the usual bayonet end. I replaced mine with a drop in LED white replacement. I have LEDs for the dial lights, and decided that since mine still work, it was not worth my time to replace them. Eventually I will. Geoff. -- Geoffrey S. Mendelson, N3OWJ/4X1GM Making your enemy reliant on software you support is the best revenge. ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] Ten-Tec and Drake Compared
On Jun 17, 2011, at 7:51 AM, Darrell Bellerive wrote: In the 70's Ten-Tec had the Tritons, and early Omni's, with the Corsairs in the early 80's. Before the Corsairs, with the Tritons, Argos, early OMNIs and Century (21,22, 22 digital display) rigs Ten-Tec went for simplicity of design and good sound. Compared to the design of the Colins (sophistocated and no expense spared), the Drake (near genius), the Ten-Tec rigs look like they were designed by copying pages from Doug DeMaw's books. I am NOT saying that the Ten-Tec rigs are poor performers, far from it. For casual rag chewing, I'd put my Argo 509 or Trition IV Digital (display, not oscillator) against any modern rig. In the Drake rigs I've seen every part is carefully placed, every wire carefully run, every joint carefully soldered. My SPR-4 manual warns against changing the length or route of wires as it may affect performance. I don't know if it would affect the Ten-Tec rigs in the same way, but it does not seem so. The designs seem to be simple circuits. The Century rigs have direct coversion receivers. Geoff. -- Geoffrey S. Mendelson, N3OWJ/4X1GM Making your enemy reliant on software you support is the best revenge. ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] Smoke damaged TR-4CW
On May 16, 2011, at 4:30 PM, Charles Ring wrote: Does compressed air have any advantage over suction from a shop vacuum with a small paint brush? I've never liked to blow the dirt around. You never get the pressure and fine control of a blast of compressed air with a vacuum hose. It is better to vacumm as much as you can, because it is a lower force method and less likely to jam particles of dirt, smoke, etc into things. There are places where a vacuum is not strong enough, nor a brush able to reach, and for those a short blast of compressed air from a small source will do wonders. The trick is to look first and make sure you are pushing things out, not farther in. Geoff. -- Geoffrey S. Mendelson, N3OWJ/4X1GM Occam's Razor does not apply to electronics. If something won't turn on, it's not likely to be the power switch. ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] Deoxit at Musician's Friend
On Apr 2, 2011, at 3:16 PM, Woody wrote: Since I started back on my Drakes I couldn't find a source for Deoxit locally, when I found it on the net they wanted as much for shipping as the 5 oz can cost. I found it at Musician's Friend for $14.98 and FREE shipping. I'm not plugging them just thought you might like a source for it and not have to pay an arm and half a leg to get it shipped. Being outside the US, I have a problem with it getting shipped here at all. I found a company on eBay that sells it and ships it out of the US. They are called PhoneKings.com and have their own website too. I ordered Deoxit 100 in the little tube, and they stuffed them (I ordered 3) in a little padded envelope so it came here in a week. If found that I needed "fader lube" too and they did not sell it alone, so I ordered a combination set which was on sale that week. I also sent them an email saying I would of preferred just the fader lube. They added just the fader lube to their website. My order of the combination packages never arrived, so I emailed them and they sent me a new set. That came in slightly over a week. Geoff. -- Geoffrey S. Mendelson, N3OWJ/4X1GM Those who cannot remember the past are condemned to misquote it. ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] restoring
On Feb 25, 2011, at 9:44 AM, John Hudson wrote: then the unit is power washed with clean distilled water ^ So the dishwasher is not a bad idea provided you don't use the soap, and not sure how simple green would work in a dishwasher. Actually it's a horrible idea. Dishwasher water is municipal water loaded with minerals, chlorine and that favorite of the commies, flouride. (just joking about the commie part). I read on one of these lists that the water used by Techtronics to wash their repairs was naturally pure well water and almost the same as de-ionized water. A far cry from municipal water. Geoff. -- Geoffrey S. Mendelson, N3OWJ/4X1GM Those who cannot remember the past are condemned to misquote it. ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
[Drakelist] SPR-4 medium wave antenna?
I live in a "sea" of electrical noise and need an antenna for the SPR-4 for AM broadcasts. I tried to duplicate the loop that was made for the SPR-4 using RG-6 and it simply did not work. The broadcasts were weaker than the noise. Even using the loop (with my HF antenna disconnected) the noise was stronger than the calibrator. So I need to locate antenna outside the noise, which means I need to use about 10 meters of coax. Due to availability and price, I've decided to use RG-6 coax. I can run an antenna at about 6 feet above ground level (in a valley) and a maxiumum of 11 meters long. What should I use? A dipole? An end fed wire? If I use an end-fed wire what do I ground? Should I make a 9:1 or other transformer? I have several sizes of Russian made ferrite rods with a permeability spec of 400. I only have #24 stranded plastic insulated and 1mm solid plastic insulated wire. Should I connect the coax to the antenna input or the loop input? The receiver is on the second floor. At the far end of the antenna is an HF vertical that goes to the first floor, and there is a ground rod there. If I do ground the coax or use a transformer, I can either run an extra 10 meters or so and put it near the ground rod (and other antenna), or put it closer and run a 10 meter 1mm solid wire to the ground rod. Thanks in advance for any advice. 73, Geoff. -- Geoffrey S. Mendelson, N3OWJ/4X1GM Those who cannot remember the past are condemned to misquote it. ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] Blue LED Bulbs for Drakes
On Feb 3, 2011, at 7:47 AM, Dennis Monticelli wrote: The LEDs in this product look just like the ones that come in the XMAS lite strings. That market probably drove mass production and low prices, which in turn enabled this outfit to build a bulb. It would probably benefit from a diffuser in some applicatons. I have not seen the ones you are discussing. I bought mine elsewhere. The ones that I have bought are not like old fashioned LEDs. The LEDs themselves seem to be some sort of plstic diffuser, so they radiate light in almost all directions (the light is blocked by the leads). They actually radiate more evenly than a real bulb does. In some cases, I've thought of making a reflector from aluminum foil to focus the light more. The bulbs are the LEDs stuck into a base with some circuitry that allows them to run on the same voltage as the bulbs they replaced did, and they can run on AC or either polarity DC. They function in series and the #47 replacements work with a dropping resistor designed to run a #47 on 12 volts. I've also bought 12 volt versions, which work perfectly in radios that run them directly off of a 12v (13.8v) supply. I'm not sure if a purist would want them. The white ones are too blue to match a #47 exactly. On my SPR-4, it does not matter, the one bulb which is unfiltered shows up fine, and the other two which are blue filtered I replaced with blue ones anyway. It may not look like Drake intended, but the look is IMHO "good". Geoff. -- Geoffrey S. Mendelson, N3OWJ/4X1GM Those who cannot remember the past are condemned to misquote it. ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] Blue LED Bulbs for Drakes
On Feb 3, 2011, at 1:42 AM, Kevin Elliott wrote: First I want to say I am sorry if this upsets the person that is making and selling the blue LED bulbs on Ebay and other web sites. I just can't afford to pay $30.00 plus shipping for 2 bulbs. So I went looking for a different source and I found one that was much cheaper. The company sells #47 Blue (or other color) LED bulbs. The best thing is the price... $1.58 each. The worked perfect on the main dial but were not quite bright enough for the meters until I took the reflector off and scrubbed it white again. Now for $3.18 I can but the blue bulbs in the TR-4 or even opt for red since I ordered some of them and they look very nice as well. I got them for around that, possibly less (depends upon color) from . They have really good technical support, I was trying to figure out how to replace the grain of wheat bulbs in a Ten-Tec Argonaut 409, and we had a fairly long email conversation about it. I used them to replace the bulbs in my SPR-4, blue bulbs for the meter and VFO dial, and a white one for the crystal switch. It looks good, but I would prefer a little more read in the white one. They ship small quantities in a flat envelope which makes international shipments go faster. My orders came in a week, except for when I ordered too many (actually less cost, they were "bare" LEDs instead of bulbs) and they sent them in a box. That took almost three weeks. Geoff. -- Geoffrey S. Mendelson, N3OWJ/4X1GM Those who cannot remember the past are condemned to misquote it. ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] TR7A no AM modulation
On Jan 9, 2011, at 12:00 AM, Joe Pyles wrote: You do not need the AM filter to transmit AM. It does not matter what mode you transmit in, on a TR7 it always uses the 2.3khz sideband filter. When you transmit AM, you transmit carrier plus upper sideband (A3- H). Thanks for correcting me. The TR-7 I owned had no filter, nor the mod, so I was uable to receive AM with it. I had never tried to transmit in AM, since I had no way of receiving any response. Thanks, and 73, Geoff. -- Geoffrey S. Mendelson, N3OWJ/4X1GM Those who cannot remember the past are condemned to misquote it. ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] TR7A no AM modulation
On Jan 8, 2011, at 10:38 PM, Demis Bertoni wrote: Hi All, I have buyed on ebay a TR7A in good condition, but not functioning the AM modulation. LSB and USB no problem. I have replaced the transmit exciter board without result... Do you have a solution to this problem? I have not owned a TR-7 in 14 years, so I may be wrong, but: Does it actually have an AM filter in the IF? (6kHz). The TR-7 would not transmit nor receive AM without the filter. Someone figured out that a simple resistor in place of the filter would make AM reception possible (but not as good as with the filter). The "mod" was incorporated by Drake in the TR-7a, giving all of them AM reception. However, you still need the filter to transmit. Geoff. -- Geoffrey S. Mendelson, N3OWJ/4X1GM Those who cannot remember the past are condemned to misquote it. ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
[Drakelist] SPR-4 without noise blanker nor jumper cable.
My SPR-4 has neither a noise blanker nor a jumper cable in it's place. From what I can see it looks like it never had either of them. Is it necessary? If it is where do I get one? Can I just replace it with a length of plastic insulated unshielded wire? Does it have to be shielded? Is the lenght important? TIA, Geoff. -- Geoffrey S. Mendelson, N3OWJ/4X1GM Those who cannot remember the past are condemned to misquote it. ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] Blue LEDs
On Dec 3, 2010, at 10:47 PM, Bob Jackson wrote: What's the general opinion of the replacement pilot lights that are actually blue LEDs? Someone (I think it was on this list, may have been on another) suggested superbrightleds.com. They have LED replacement blubs for standard bayonet bulbs, which will work with either DC or AC and will work in series. They provide light in 180 degrees, so they really do replace regular bulbs. I replaced two of the #47 bulbs in my SPR-4 with blue bulbs and the other with a white bulb. The white bulb is a bluer than a #47, but still useable, and the blue bulbs give it a very nice "look" IMHO. The main advantage of them is that there is no more effort required than changing a light bulb, and you can change them back at any time. Geoff. -- Geoffrey S. Mendelson, N3OWJ/4X1GM Those who cannot remember the past are condemned to misquote it. ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] Drake Accy's
On Oct 28, 2010, at 9:11 PM, Bob Jackson wrote: For an SPR-4, I'm looking for: • 5-NB noise blanker • SCC-4 Crystal Calib. Failing that, does anyone know if there's PCBs available to HB my own? I have not actually done it, but I bought a $10 crystal calibrator from eBay with the intention of putting it in my SPR-4. I'm torn between surgery on my radio and mounting it in an external box. Eventually I may track down a plug and do it that way. I'm not in the US, so I can't just go to a surplus store (the only one in the country is an hour by car and I don't have one), and I can't order from the usual places without paying $35-$50 in postage. This was discussed here in the past, with Garey giving full details on how to connect it. • Also looking for a roll of decals for the preselector dial. That's a hard item to find. Someone here mentioned using a Brother P- Touch type device and clear tape to make them. While I am at it, I replaced the #47 bulbs in mine with LED bulbs. I used blue bulbs for the tuning dial and s-meter and a white one for the band switch. Geoff. -- Geoffrey S. Mendelson, N3OWJ/4X1GM To help restaurants, as part of the "stimulus package", everyone must order dessert. As part of the socialized health plan, you are forbidden to eat it. :-) ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] Blue Filters for B and C lines
On Oct 19, 2010, at 3:43 PM, Garey Barrell wrote: Sorry guys. Fingers faster than brain. The correct number is # 172, 'Lagoon Blue' from Lee Lighting. Do the filters cover the entire part you want lit? I had good results with my SPR-4 replacing the two blue filtered lamps with blue LEDs "bulbs". They look and work just like #47 (although they have 12 volt ones too) bulbs. I replaced the middle one with a white "bulb". I got them from superbrightleds.com. Geoff. -- Geoffrey S. Mendelson, N3OWJ/4X1GM To help restaurants, as part of the "stimulus package", everyone must order dessert. As part of the socialized health plan, you are forbidden to eat it. :-) ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] Preselector lube
On Aug 26, 2010, at 12:29 PM, Ron wrote: Paul, Last time I did one, I used a small amount of kerosene to thin out the old lube. In my case the kerosene seemed to restore the old lube enough that there was no need to remove the old lube and replace with new. I would agree with Garey about that system being a "bit mechanical" when it comes to removal and re-installation and the like. There are many articles on rebuilding Ten-Tec PTO's on the web. Most of them discuss various greases and lubricants you can use. A quick search for "ten-tec PTO rebuild" should give you lots of ideas. Geoff. -- Geoffrey S. Mendelson, N3OWJ/4X1GM To help restaurants, as part of the "stimulus package", everyone must order dessert. As part of the socialized health plan, you are forbidden to eat it. :-) ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
[Drakelist] SPR-4 crystal calibrator wiring
I recently got an SPR4 and while as a receiver I am very happy with it, I always have been disapointed with the dial calibration. The crystal calibrator seems to be way off and wanders all over the place. I looked at the radio itself and found that there is no crystal calibrator in the radio (it was an option), what I thought was the calibrator was random carriers and noise. (oops). I just purchased from eBay a simple crystal calibrator. I'll have it in about 2 weeks. I looked at the schematic of the radio and there are 4 wires that come from the original calibrator. One is ground, one is the signal to the antenna section of the radio. The other two I really don't understand. One goes to the on off switch for the calibrator and the other I'm not sure about. The calibrator I bought has 3 connections, ground, +9 to 12 volts DC, and a signal out. Looking at the picture in the eBay ad, I probably have to add a small capacitor from the output to the radio, so it does not load down the input. Ground is obvious. What do I do with the +DC? The schematic for the radio does not show what actually is switched by on off switch. My guess is that the other wire I'm not sure about provides the DC input, and the on/off switch either grounds or "floats" a buffer circuit on the calibrator board. This makes a lot of sense to me, as it would keep the calibrator on all the time, but only injecting a signal when needed. Of course, I could be completely wrong and the on/off switch turns on and off the calibrator and I have no clue about what the fourth wire does. Any advice would be appreciated. Thanks in advance, Geoff. -- Geoffrey S. Mendelson, N3OWJ/4X1GM To help restaurants, as part of the "stimulus package", everyone must order dessert. As part of the socialized health plan, you are forbidden to eat it. :-) ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] Hamvention Drake Forum
On May 16, 2010, at 7:10 AM, LEE BAHR wrote: Why don't you give a run down as to what is on the DVD? Without knowing what was covered, I among others may have no idea if they want the DVD. Isn't that what YouTube is for? If you want to restirct distribution, you could put it on rapidshare, megupload, hotfile for filefactory and then only give out the url on request. If you really want to restrict distribution, upload it as an encrypted RAR file and only give out the password as necessary. Geoff. -- geoffrey mendelson N3OWJ/4X1GM Jerusalem Israel geoffreymendel...@gmail.com New word I coined 12/13/09, "Sub-Wikipedia" adj, describing knowledge or understanding, as in he has a sub-wikipedia understanding of the situation. i.e possessing less facts or information than can be found in the Wikipedia. ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
[Drakelist] Relamping an SPR-4, the conclusion
I'd like to thank everyone who helped me with my problem of relamping my SPR-4. I found what may have been the last box of #47 bulbs in the country and put them in. Someone on another list used replacement bulbs from http://www.superbrightleds.com/ and was happy with them. I went to their website and found they had a direct replacement for the #47 bulb. It is a white LED, with the same output (180 degree) as an incandescent bulb, works with AC or DC and has about the same resistance, so you can use them where you have two of them in series. They were $2 each, with a $25 minimum order. The good news is that they ship USPS, so for under $6 shipping, they arrived in my mailbox in a week. For comparison, a regular bulb store I found that would ship overseas wanted $13 for the bulbs and $15 shipping, and Farnell has $35 minimum shipping fee. I put them in my SPR-4 and I am happy with them. They are white as in daylight (5500K color temp) versus the #47 bulbs which were white as in regular incandescent bulbs (3200K or less, much more red). The SPR-4 uses them in two ways. One is with a blue(ish) filter for the S- Meter and tuning dial, and they work fine. The third bulb is more complicated, it is used to show the frequency range, and bandswitch and preselector settings. The filter it goes through is clear in the center to highlight the correct settings in "white" and the edges in blue. This also works perfectly. They also have 12 and 24 volt versions, and blue, green and red colors. 73, Geoff. -- geoffrey mendelson N3OWJ/4X1GM Jerusalem Israel geoffreymendel...@gmail.com New word I coined 12/13/09, "Sub-Wikipedia" adj, describing knowledge or understanding, as in he has a sub-wikipedia understanding of the situation. i.e possessing less facts or information than can be found in the Wikipedia. ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] TR7 zener diode noise
On Apr 26, 2010, at 12:40 AM, Garey Barrell wrote: The Fairchild data sheet I looked at for the LM78XX series showed a 0.33 uF on the output. Drake seems to have used a 1 uF tantalum (solid) on ALL the "ins" and "outs". The tantalum cap should be ok for 3-30 MHz, but is that TOO much capacitance. My experience says that a 0.33 disc ceramic would be less expensive than the tantalums, so I would assume that Drake thought it would be better. I remember when the consumer magazines starting writing about the LM78xx regulators. They all wrote that one MUST have a 1uF tantalum capacitor bypassing the input and output. I had never heard of a tantalum capacitor, and had never seen a 1uF capacitor that small. I don't know where the concept came from, but my data books had them in the application notes. It's quite likely that someone decided that a 1uF tantalum capacitor was what someone thought would be "bulletproof", i.e. it would never be too little capacitance, and it was better to specify something much too big, than to let people figure it out on their own and get it wrong. As far as I can remember, circa 1975, the concept of making things as small and as cheaply as possible with as few components as close to their limits as you could specify them had not yet arrived in consumer electronics. After all consider the parts that were replaced by one, and the extra cost of the capacitors was trivial. Geoff. -- geoffrey mendelson N3OWJ/4X1GM Jerusalem Israel geoffreymendel...@gmail.com New word I coined 12/13/09, "Sub-Wikipedia" adj, describing knowledge or understanding, as in he has a sub-wikipedia understanding of the situation. i.e possessing less facts or information than can be found in the Wikipedia. ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] 220V vs 240V power - it's not just the voltage...
On Mar 25, 2010, at 2:34 PM, iz oos wrote: that is interesting! I've learnt today that in Italy we use 50Hz. My AC-4 runs quite warm indeed. Actually its "230" Volts 50Hz. I put the 230 volts in quotes because due to EU normalization, the power grids in all EU countries which used to be either 220 (continental Europe) and 240 volts (UK) were normalized to 230 volts. The specification was wide enough that the normalization was a formality, no one actually changed anything. So your 230 volt EU normalized electrical outlet gives you 220 volts, while an Englishman's 230 volt normalized electrical outlet gives him 240. The short time effect of this is that electrical goods sold in the EU no longer could be adjustable for 220 or 240 volts, they had to be "230 volt" and work equally as welll (and as safely) on anything from 220 to 240. The long term effect will be that the contiental power grid will slowly be raised to 230 volts, the UK lowered to match it, and then they will interconnected. It may not happen in our lifetimes, but it might, one never knows. As for the frequency, the difference in power is 20% and it's radiated by the transformer as heat. Geoff. -- geoffrey mendelson N3OWJ/4X1GM Jerusalem Israel geoffreymendel...@gmail.com New word I coined 12/13/09, "Sub-Wikipedia" adj, describing knowledge or understanding, as in he has a sub-wikipedia understanding of the situation. i.e possessing less facts or information than can be found in the Wikipedia. ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] receiver xformer
On Mar 11, 2010, at 8:36 PM, Garey Barrell wrote: Yeah, they all run hot. I don't know if they are short on iron, or copper, or what. They are epoxy sealed, which I guess makes them run a little hotter. All that aside, I have yet to see one fail unless a cap shorted and someone had replaced the fuse with a piece of #000 wire (I've seen both :-) ) Don't forget that a transformer is not 100% efficient. At 60Hz about 15% to 20% of the electricty in comes out as heat. So if your receiver draws an amp at 115 volts, around 20 watts of heat are coming out of it. Some "solid state" receivers are notorius for "running hot", the Kenwood r5000 and Drake R8 for example. As an aside, you would be surprised to find out how many people move here (or to other countires with 220/230/240 volt 50Hz power) and bring their old appliances because they were told it is easy to get a transformer for them. Easy yes, cheap no. Someone I know just paid $150 for a custom made transformer for her vacuum cleaner which will put out almost 200 watts of heat on its own. :-( Geoff. -- geoffrey mendelson N3OWJ/4X1GM Jerusalem Israel geoffreymendel...@gmail.com New word I coined 12/13/09, "Sub-Wikipedia" adj, describing knowledge or understanding, as in he has a sub-wikipedia understanding of the situation. i.e possessing less facts or information than can be found in the Wikipedia. ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] T-4X Audio Question
On Feb 28, 2010, at 10:13 PM, Hulett, Russell wrote: Trying out my T-4X on SSB, using an old D-104 microphone with T-UG8 stand. Comments were audio was ok but sounded like I was "in a tunnel". Another mentioned that the audio was higher pitched than my other rigs. My T-4XB never received any similar reports, though the microphone used with that rig is a D-104 on a G base Since they are easily swapped, try changing the heads and see what happens. There were two versions of the D-104 head, and a pin compatible dynamic mic, the 10-DA. The 10-DA looks like a bullet head, the D-104's are the lollypops. The 10-DA has much better bass response, and works well for me, having a very low voice. The D-104's two versions have much higher response and less bass. One is the usual crystal one, which is the most popular and the best sounding. There was also a ceramic version which had a narrower response, but was harder to damage and had less problems with humidity. The D-104 inside had a black grill cloth and then a layer of fiberglass insulation. These adjusted the frequency response of the microphone. There are lots of "improvement" mods floating around, some modify the cartridge itself, others replace or remove the grill cloth and the fiberglass. AFAIK, removing the grill cloth does nothing to (or for) the sound, modifying the fiberglass has a big effect. There were also many D-104 "clones" or similar microphones in D-104 cases, etc. It's possible that one mic is a stock D-104, the other has a crystal or modified head, or a "clone". Then there is the issue of the amplifer. From what I understand (Garey help!!) the impedance of the D-104 is a good match to the impedance of any of the Drake tube gear and no amplifer is needed. The amplifer was designed as an impedance matching device, not a gain producing device, although it does have some gain. If you have an amplified stand, make sure the battery is fresh and the gain is relatively low (1/2 way or less). Even better, remove the battery and jumper out the amplifer completely. I can't guarentee that it works for all Drake rigs, I've only owned transistorized ones. I hope that helps. Good luck and 73, Geoff. -- geoffrey mendelson N3OWJ/4X1GM Jerusalem Israel geoffreymendel...@gmail.com New word I coined 12/13/09, "Sub-Wikipedia" adj, describing knowledge or understanding, as in he has a sub-wikipedia understanding of the situation. i.e possessing less facts or information than can be found in the Wikipedia. ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] Unsubscribe from email:
On Feb 23, 2010, at 2:43 PM, Nigel Gunn G8IFF/W8IFF wrote: You go to the URL at the end of every e-mail you receive from the group, log on and edit your preferences. One of the options is to disable (turn off) email delivery, also known as vacation mode. That way you can read the postings on line without getting any emails, but still be able to post. Considering that you have to sign up and be approved to post, this can reduce the time and effort if you have a question and need an answer. You could also chose digest mode, where you get one email a day. On busy days you can just delete it, on slow days, take a look at it. A friend of mine calls it "New York mode", because you can shout without listening. :-) Geoff. -- geoffrey mendelson N3OWJ/4X1GM Jerusalem Israel geoffreymendel...@gmail.com New word I coined 12/13/09, "Sub-Wikipedia" adj, describing knowledge or understanding, as in he has a sub-wikipedia understanding of the situation. i.e possessing less facts or information than can be found in the Wikipedia. ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] Could I ask any of you D-104 owners to perform a load pull test?
On Dec 21, 2009, at 12:41 AM, Dave Haupt wrote: I borrowed two D-104s locally - turns out that later production used either a ceramic or a high-Z dynamic element, and both were quite insensitive to load. Dave, Around 1995, I was rebuilding several Astatic microphones and called the factory and spoke to an engineer there. There were two versions of the D-104 made. One had a crystal cartridge, which is the standard D-104 we all know and love. The other had an optional ceramic cartridge, which was used not because of its sound quality, but it's ability to withstand a wider temperature and humidity range. As he put it, the memory key was "crystal clear". Astatic never made a D-104 with a dynamic cartridge. The closest they came to it was (is?) the 10-DA, which instead of the round head has a bullet shaped head. They fit the D-104 stand and that may be where the confusion comes from. The 10-DA has an internal transformer, which is probably why they had the bullet shape, it had to go somewhere. :-) If you have a round, flat head D-104 with a magnetic element in it, it was probably a modification done by someone who did not either like the response of the crystal cartridge (I find they don't have enough low frequency response for my voice), or rebuilt it and decided it was much cheaper to tear the mike out of a CB handheld and put it in than to buy a new cartridge from Astatic. I don't remember the price, but they were not cheap. In any case, I'm not sure what kind of low frequency response you are going to get out of a crystal cartridge anyway. Bear in mind that they were communication and PA microphones, not for music. People with low voices that wanted that part of their voice to come through used the 10-DA instead. 73, Geoff. -- geoffrey mendelson N3OWJ/4X1GM Jerusalem Israel geoffreymendel...@gmail.com New word I coined 12/13/09, "Sub-Wikipedia" adj, describing knowledge or understanding, as in he has a sub-wikipedia understanding of the situation. i.e possessing less facts or information than can be found in the Wikipedia. ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
[Drakelist] ham radio magazine article on drake, redux.
I have the magazine as a pdf file of scanned images. I looked in the table of contents and could not find it. However you can download an index of the articles in the entire series from: http://webhome.idirect.com/~griffith/hrindex.htm Searching the index for Drake, I found a reference to page 81, January 1979. "Improved tuning on 160 meters with the t4x transmitters". Enclosed was a pdf file of the single page, assuming it goes through. It did not, at 160k it was to big for the list, so I'll email it to anyone who asks. 73, Geoff. -- geoffrey mendelson N3OWJ/4X1GM Jerusalem Israel geoffreymendel...@gmail.com New word I coined 12/13/09, "Sub-Wikipedia" adj, describing knowledge or understanding, as in he has a sub-wikipedia understanding of the situation. i.e possessing less facts or information than can be found in the Wikipedia. ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] TR7 questions
On Dec 8, 2009, at 7:40 PM, Garey Barrell wrote: Geoff - That's what had me confused. The RV-75 is the synthesized VFO, and has the greatly improved stability. The base TR-5 is the same PTO as the rest. OOPS, I should have said it was more noticable IN COMPARISON TO, or BY USING an R-75. Sorry for any confusion. Geoff. -- geoffrey mendelson N3OWJ/4X1GM Jerusalem Israel geoffreymendel...@gmail.com ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] TR7 questions
On Dec 8, 2009, at 5:29 PM, Garey Barrell wrote: Carl - I've been corrected on the '5 PTO. I wonder how the much improved stability of the '5 is accomplished.? I'm sure it is, for the first hour or so, my TR-5 wanders from a "cold start". It's really noticable with the RV-75. 73, Geoff. -- geoffrey mendelson N3OWJ/4X1GM Jerusalem Israel geoffreymendel...@gmail.com ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
[Drakelist] relamping an SPR-4 with LEDs.
According to the manual, the SPR-4 itself uses about 1/3 of the electricity of the three #47 lamps in it. This IMHO makes it a prime candidate for replacing them with LEDs. Mine are burnt out and I don't have any spares. There are several problems with doing so. The first is that when the receiver is run on AC the lamps are powered by the main power transformer, before the rectifiers. Two of them are in series. The third lamp is in series with a resistor which approximates the load of the "missing" fourth bulb. The other more obvious problem is color. If you look at the pictures of an SPR-4 with the "lights on", on the Universal Radio web page, you can see that the S-Meter and Tuning displays are blue, while the crystal switch (in the middle) is clear for the selected crystal and blue around it. I assume that I can use white or blue LEDs for the S- Meter and Tuning, but what do I do for the crystal switch? A blue LED would not do, it would just be blue on blue, which would be almost impossible to see. A white LED, which all the ones I can get are very blue, would be similar. Maybe a white and red LED together? Are the such things as "warm" white LEDs? Since I plan on using it soley on AC power, should I just give up and try to find some bulbs? It's in good shape electricaly, but it looks like it sat in a dusty storage area for 20 years. I've cleaned it up but it will never be a collector's display item. Geoff. -- geoffrey mendelson N3OWJ/4X1GM Jerusalem Israel geoffreymendel...@gmail.com ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
[Drakelist] SPR-4 crystals
I've been thinking about getting more crystals for my (new to me) SPR-4. I know I can get custom crystals cut, but that may be too expensive. I found someone who sells reasonably priced crystals for the 4 line radios, however, his crystals are listed as being slightly different than the ones in the SPR-4 manual. For example, his is listed as the one for 10 mHz reception is 21.100 mHz, the manual lists it as 21.09 mHz. (note the difference in decimal places) Is this just a rounding error? Is there really a difference? Will 10kHz make a lot of difference? These would be for adding ham band reception, which except for 40m is missing. Thanks in advance? Geoff. -- geoffrey mendelson N3OWJ/4X1GM Jerusalem Israel geoffreymendel...@gmail.com ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
[Drakelist] SPR-4
I am now the proud owner of an SPR-4, serial number 5676. It looks like it sat on a dusty shelf for a while, it is dusty and the ends of some things, such as the screws, rf gain knob (if you can call it a knob), are rusty. It has two problems. One is the dial sometimes "sticks". The other is a loud hum from the speaker no matter what setting of the audo gain control. Looking at the schematic, all of the power supply filtering is a 1000mf/25 volt capacitor. Is this the source of the hum? Is it likely that it will reform by leaving the radio on for a few days? Thanks in advance, Geoff. -- geoffrey mendelson N3OWJ/4X1GM Jerusalem Israel geoffreymendel...@gmail.com ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] Drake separates
On Sep 14, 2009, at 5:07 PM, AirRadio wrote: Right then, this will I am sure occur lively debate, I have a couple of L-4B (B&C versions) linears and MN-2000's that I regularly use with 'other' radios, it has occured to me at various times to maybe get a tx & rx of Drake manufacture to go with them, however there are a great variety to choose from and not being well versed with Drake radios other than the amp and atu, I am a little lost as to what I should look for. Basically I would like to have something that covers 160-6m inc warc cw/ssb now the TR-6 will do the 6m but is it good and do I need other bits to go with it, maybe some mods or other is required? the 160-10m side then a seperate tx and rx maybe better than a transceiver? please guide me on this as I have heard one or two of the Drake receivers give even modern radios a run for their money. Obviously power units, speakers, mics, Sherwood mods etc need to be considered too. First of all, top of the line modern radios are far better than anything Drake made, with any mods anyone has thought of IN SOME SITUATIONS. If you want the features and performance of a TenTec Orion, an Elcraft, or the new $10,000 Icom rig, buy one and be happy. If you want something that has the look and feel, as it were, of a radio, then that is another story. For example, I could never warm up to the R-8 because IMHO it is more like a stereo or satellite TV receiver than a ham/shortwave radio. I'm very happy with my TR-5. As for bands, Drake never AFAIK made a 6 meter radio with HF too. The TR-6 was it. WARC bands are another problem. The TR-5 had them included, the TR-7 could be modified to transmit anywhere in the 160-10m range, but the tube radios won't. You probably can modify them to work, but mods are expensive, and do not always give you what you expect. Depending upon the mod, the quality of the work, how much it changes the performace and appearance, it may reduce the value of the radio, something you probably won't want. The US ham radio market was pretty much on the way down when the transistor rigs were made (TR-5 and TR-7), so not many were sold in comparison to the tube rigs. This raises price and lowers availability. The digital VFO (RV-75) for them is extremely rare and can go for as much as a whole station of older rigs. Note that they look different than the older rigs and if you want something with matching paint, they are out. On the other hand, a TR-5 or TR-7 will do what you want out of the box, as it were, is a nice radio, and likely to work with no mods, repairs, clean-up etc. My guess is the last thing you do right now is to buy an "education" as opposed to a working radio. 73, Geoff. -- geoffrey mendelson N3OWJ/4X1GM Jerusalem Israel geoffreymendel...@gmail.com ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
