TR-4 Filter Match
3
Okay, I need a little help from the real engineers here. When doind a TR-4 filter match adjustment, I invariably come up with having to redo the adjustment several times. T6 and T13 appear to be at opposite ends of the filters. I can see why you want to get the received strength the same by tuning the PTO to the one place where the signals on opposite sidebands have the same strength and I get using S3 as the signal before tweaking the transformers so that you're not overloading anything (overcoupling?) Why does it seem to take 3-5 cycles of this? The TR-4 I'm working on has a host of problems (and I'm about to set it aside for a couple of months, as the owner has told me to "take my time". and the filter match was way out of adjustment -- implying that someone else was "in there" and didn't do the procedure quite right. Do these filter match transformer adjustments interact? I am inclined to believe that they do. What happens if the adjustment is off? Simply reduced response on one sideband? This TR-4 has had 4 bad tubes, plus bad finals, and an intermittent fault that comes as the rig warms up -- but -- the problem also disappears with the rig warmed up. Voltage checks on some of the tubes have revealed some voltage differences that I'd largely chalk up to old resistors. They're in the ballpark. It's too bad, because this set is about an 8.5 cosmetically... 73, Steve Wedge, W1ES Time flies like an arrow. Fruit flies like a banana. Sent with Proton Mail secure email.
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Hamvention event, local restaurants
3
Fellow Drake Enthusiasts, Having been asked about where to eat come Hamvention time, I thought I'd throw out my favorite restaurants since I live in Greene County. Lumberton General Store is on Route 68 south between Xenia and Wilmington. It is family owned, great food, and excellent customer service, with reasonable prices. Open from 7:30 AM until 2 PM, but closed on Monday. Sam and Emma are the owners. Just tell them or the servers "Evan sent me". Cherry House in Beavercreek off of Dayton-Xenia Road. Also family owned, wide selection of great food with excellent staff. When you walk in don't be discouraged by the crowd, there is a whole section to the right, the overflow room, with fast service. Open from 7:30 AM until 8 PM, closed on Sunday. Bill and Annette are the owners. Just tell them or the servers "Evan sent me". Nick's Restaurant on Route 68 North out of Xenia, not far from the Hamvention. Fantastic, huge burgers and many other selections. Lisa and Nick are the owners I believe. All of the above have websites showing their menus and pricing. I have no financial benefits from these restaurants, I'm just a satisfied patron! Let's all enjoy Hamvention!!! Bring rain gear and sunscreen, you'll need both as in past years. 73, Evan, K9SQG
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Another TR7 Journey begins
186
I had a TR7 about 15 years ago and loved it but I sold it to help finance my K3 purchase, which I also love and still have. I acquired a TR7 today from an estate today with the PS7. It's S/N 2713. The thing was pretty dirty and will need a case repainting but seemed OK otherwise and the price was right. Here's what I have gleaned so far: 1. The PS7 doesn't work. I hear the transformer thunk when I turn on the rig and the fans on the PS and TR7 both come on but nothing else. The fuse is good and not blowing so I'll need to fix that at some point. 2. The rig came on fine with a different PS and seems to RX and TX fine but power out was around 170 watts and the ALC light was not coming on. I adjusted the control on the ALC board to about 150 watts on 20M at full drive and the ALC light now works but stays on no matter how low I adjust the drive. I know there's another adjustment for that on 10M on a diffferent board but I haven't gotten to that yet. Power doers adjust down to zero now. 3. The S-meter reads very low but signals sound fine so guess that's another adjustement I need to make. Forward and reflected hardly move the meter and adjusting the controls by the antenna socket make no difference. 4. Some good news is that all 4 filter slots are full which is great news for a CW op like me. 5. There's a big change in noise between USB and LSB looks like carrier balance is off. 6. The sidetone volume level is very low, I have to turn the volume control way up to hear it. I do have a PDF copy of the service manual. The big question is will I need the board extenders to fix all this and properly align the rig? If so wheer can I find some that won't cost me too much? My apologies in advance for the many stupid questions I'm sure I will ask as this project moves foward! 73, Bill NZ0T
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Sylvania 6JB6 tube - NOS
I am liquidating radio assets here (I have quit eBay selling after 27 years). I am selling the last new old stock Sylvania (rebooted, tested) 6JB6 that I have. The test data is in the photo. It tests as a new tube should. The tube is 3.15 inches tall, not counting the pins. Including the pins it is 3.52 inches tall. $30 shipped in CONUSA. Gary W0DVN PPS: If you¡¯d like to know WHY I quit eBay, drop me a direct note and I will tell you! It¡¯s not appropriate to post in this forum.
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TR7 R7 left Endcap with photo
While cleaning, I found that I have a TR7 R7 left Endcap. It is in very good condition, no cracks near the screw holes. It is original, not a reproduction, so it will not shrink over time. $15 mailed in CONUSA. Gary W0DVN
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R7 "Cadaver"
I am liquidating radio assets here so I am posting my R7 ¡°Cadaver¡± (I have quit eBay selling after 27 years). It does not work. The PTO is gone. It does not have a case or knobs. It has all boards, but the DR7 is known to be bad with missing parts. The other boards were tested. In my other R7 before it went away. He power supply boards do not work, but ar not toasted so would easily be repaired. To my recollection, all of the other boards worked when tested in that same R7. I can sell it as complete as it is for $300 plus shipping. If no one wants it this way, I can sell off parts to those who need them. PS: The front panel extrusion and sub-panel are quite nice. Gary W0DVN PPS: If you¡¯d like to know WHY I quit eBay, drop me a direct note and I will tell you! It¡¯s not appropriate to post in this forum.
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TR7 R7 left Endcap
While cleaning, I found that I h ave a TR7 R7 left Endcap. It is in very good condition, no cracks near the screw holes. It is original, not a reproduction, so it will not shrink over time. $15 mailed in CONUSA. Gary W0DVN
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TR-4 : Constant tone with 100kHz Calibrator
19
When I switch on the 100kHz calibrator in my TR-4, I get a constant tone regardless of the frequency of the PTO. It's rather high-pitched, perhaps 4 kHz or 5 kHz in frequency. If I recall correctly, it seems more prevalent in one sideband setting or the other (not sure which at the moment). I presume this is not normal, correct? If it isn't, any suggestions as to what might be the problem? I know the crystal and tube are pretty close to the RF TUNE capacitor (which is in a metal cover) and am wondering if that may be where it's getting picked up but that might not have anything to do with it. I'm hoping someone else has seen this and might know where to look. Thanks, Barry - N4BUQ
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6EA8 - Brand Recommendations?
28
Still trying to troubleshoot my TR-4. I started checking the tube voltages and found a very weak 6EA8. I was getting about -1.7v at the test point so I tried swapping V1 and V3. That resulted in the test point dropping to about -0.5v. The Hickok 752A also showed the triode being only slightly above the minimum for that tube so I'm thinking of getting a pair where both halves of both tubes will be strong. Any recommendations on brands? Mine are RCA and I suspect that should be a good brand for them but I also figure that brand may not be as critical as for, say, the PA tubes. Thanks, Barry - N4BUQ
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WANTED: TR-4 SSB Filter
3
I'm looking for a TR-4 sideband filter and selector switch. There's a type that was supplied in the mid-production TR-4s that does not protrude through the chassis. Some are blue some are unpainted aluminum. Picture below is an example. I'll take the filter and selector switch or I might be open to buying a whole parts radio. I would be open to the later 8-pole filter as well (the one that protrudes through the chassis) but it's not ideal for my application. Not interested in the early 4-pole "soup can" filter. Thanks!
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SPR-4 xtal selector switch glass
11
The glass on the xtal selector switch in my SPR-4 was apparently broken and repaired. The result was miserable, so replacement is very much needed. Can anyone help? Thanks. Peter OZ8CTH
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SPR-4 tuning
7
The SPR-4 is new to me, and I am somewhat confused about tuning the radio, possibly due to the receiver being misaligned in the past. I am using the settings on the attached list provided by the previous owner, and they do not match the tuning instructions in the manual. Please see the pictures of the crystal selector and band range switch positions on 80, 40 and 20 meters. There are xtals in all 23 slots. Peter OZ8CTH
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Drakes at field day
7
Our county radio club is making plans for it's second field day event. We are still a new club with less than 20 active members, and last year was our first time out operating together. We do not compete in the contest, but instead use the event to make amateur radio visible to the public, and to gain experience in portable operation. We also only operate from 8:00 to 3:00 on Saturday. In addition, most of our members are newer, Technician-class operators, and this is an opportunity to show them the fun that can be had on HF. Last year I brought out a Yaesu FT-101E and FL-2100B, hooked to an 80m OCFD, and this setup was not only effective, but also very popular. It certainly stood out next to the more modern portable radios and go-boxes next to it. This year I would like to use my B-line, complete with a MN-4, connected to either a dipole or horizontal loop. The pavilion we will use for the event has power outlets, but I was thinking about running the twins using battery power. It seems like it would be more in keeping with the spirit of field day, and it would also be an interesting way to operate. I could use a generator of course, but they are noisy and smelly. I don't have a DC-4, but I do have an old 12v/110v power inverter, and can borrow a couple of group 31 batteries from work which should provide more than enough operating time. My concern is whether the inverter will handle the load of the transmitter and reciever, as it is rated for 230 watts peak, and 200 watts continuous at 110V AC. I have found that the R4-B draws 60 watts, but I have not been able to find how much power the T4X-B and AC-4 draw. Does anyone have experience using Drake twins in a portable setup, particularly on battery power? -- Jerry, WK4K
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A Tale of Two TR7s
3
It was the best of times. It was the worst of times. I had been off the air for 35 years. I purchased the complete station of a silent key that included a TR7 (serial #3900). I worked 49 states and 39 countries with that radio as I slowly acquired the rest of the equipment which today makes up my Drake 7-line station. Then, the display went haywire. Thinking this would be a good time to get the rig ¡°spec¡¯d up¡±, I sent it to a recognized Drake ¡°guru¡±, who worked on it and pronounced it ¡°good¡±. Sadly, it was not and after two more attempts, one of which involved driving to his residence with all of my gear, I gave up. Fortunately, I came across The Radiosmith online and sent ¡°3900¡± to him. Here¡¯s what he did to the radio previously proclaimed to be ¡°up to spec¡±: Work Performed (TR7 Serial #3900) Reworked completely mis-wired ALC LED circuit Repaired 26V and -5V power supply sections Repaired 5645 KHz oscillator on PBT board Attempted to repair damaged PA block, but still had low output on 10m Display spontaneously began erratic operation **Note** Customer elected to not pursue further repairs and sent us another TR7 ¡°7359¡± proved to be a gem; easily brought up to spec and now enjoying pride of place in my shack. Perhaps you have room in your heart for ¡°3900¡±. Consider it a rescue. At $450 plus $100 for shipping via FedEx (I¡¯ll refund any difference immediately), it¡¯s makes for an attractive project. Need a power supply to go with it? PS7 #5028 is available for an additional $175 plus shipping and PS75 #706 is available for $125 plus shipping. Both come with a handy stand that promotes generous air circulation. Photos of ¡°3900¡± are attached. Photos of the PS7 and PS75 will be sent shortly. Please contact me privately with any questions or requests for more photos or information. Best 73, Joe K4JNG
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Remaining items for sale
Fellow Drake Enthusiasts, Remaining items for sale and pickup near Hamvention: New in the box Drake RCS-4 remote coax switch with indoor control box and outside switch, $150. Heath SB-200 linear, mint, with Harbach PS upgrade, soft key, and faster changeover relay, $388.73. ME26 D/U professionally refurbished military VTVM, with amplifying/isolating probe, $50. Variac, 240V (goes to 280) 12A (very conservative), has knob but no case, $25. Johnson Ranger, "8+" on outside, operation unknown, $50. New, pocket DTMF phone dialers, produces DTMF or single tone, for testing linears, etc. $5 each. If interested please contact me off list. Enjoy Hamvention! 73, Evan, K9SQG K9SQG@... 937-426-1986
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TR-4 - Change to PA Circuits
4
In the early versions of the TR-4, for each of the PA tubes, both of the screen grid connections (pins 1 and 7) had a 470pF capacitor to GND. Starting at serial number 27500 (Version 5), Drake removed the capacitor at pin 7 on each of the three PA tubes and replaced it with a 68 ohm resistor between pin 1 and pin 7. Does anyone know why that was done? Thanks, Barry - N4BUQ
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Dayton Stuff, TR7, PS7, and MN75
2
Bringing to Dayton / Xenia my TR7, PS7 and MN75 Tuner. All in very good condition, a few scratchs on to of radio, but case repainted by Ron Ron Barker WB4HFN went thru the radio for me a few years back, power out is 110w-1.900Mhz, 120w-3.800, 131w-7.200, 132w-14.200, 110w-21.200, and 102w-28.200. Has the AUX-7 board., no xtals installed. Has all band transmit mod, and SSB variable power mod. Also have the full extender board kit to go with it My spaces 9208, 9209. Come by and look it over, Price will be reasonable......I don't think its made of Gold. Thanks, Steve KM4V
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Tr7 Refurb
10
Hi Everyone It did fire up but moving on to its side, went out of lock. It has a wire off, white and green, comes from the area under the vfo can and was lying near the front of the can. Going to upload a picture Does anyone have any idea where it goes. Thanks Mike G3ZCC Ps spent 4 hrs trying to find where it goes to. Tried putting a bright light print side. There is what looks like a pin diode going to an rfc in the space under the PTO. The white green wire, reads,continuity to the RFC. The length of the wire reaches almost to the switch area but I can't see where it could have detached from. See my pictures and you can see where on the print the wire is connected to. There is like a U shape by it. Looking at the schematic I am hazarding a guess that as the VCO is out of lock the wire connects PTO signal to the digital side. Thanks Mike G3ZCC
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Factory Original TR3 service documents
7
This is a long short but what the heck, I thought I'd ask anyway. Does anyone know where the original factory Drake TR3 service manuals/documents might be found? I would like to get a hold of the factory TR3 service manual(s). I'm not referring to the TR3 operating manual, I already have 3 copies of that manual and schematics. I could be wrong but most likely Drake destroyed those documents when they stopped producing and selling ham gear and closed up shop. My interest is NOT to make copies and sell them but rater to use them to service my Drake TR3 transceiver I recently picked up on eBay. 73 Mike W5RKL https://www.w5rkl.com
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R4-A Antenna
8
I posted this a short time ago but it seems to have disappeared. I have an R4-a but no antenna. I have the pigtail which terminated in a PL 259 so need some type of single wire antenna terminating in a SO 239. Anyone know anything available or have suggestions. Thanks. Dave
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