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Re: Early Drake R7 missing Antenna switch
开云体育Gary:I'll let others with early R-7's answer that question (my remaining one is very late) ....but on a similar note....I do know that the RR-3, rack mounted version of the analog dial R-7, and its MR-3 variant, did not have that antenna switch, at least not in any of the three that I have owned.? The later, digital VFO versions, the R-4245, and the R-77, DID have the antenna switch, so seems possible that the early R-7's did not have it.? I have to admit though, by your description of the patch job on the front panel and the hole in the sub-panel, would suggest it was there at one time.? I also checked several different sales brochures and they all show the R-7 with that Antenna Selector switch. Not much help....but all I've got to offer. 73 Peter VE7PS On 2021-04-24 4:53 p.m., Gary Follett
wrote:
Does anyone know if I should be expecting my early Drake R7 (S/N 358) to be missing the Antenna selection switch? This one has no switch and no residual wiring that would have been associated with it. There is a hole in the front panel for it, but this was plugged with a polymer filler that was textured and painted to match the gray wrinkle finish that is on the cabinet. A very distant memory suggests to me that this might have been factory, but I could certainly be in error here. Also, does anyone have an Aluminum panel extrusion for either the TR7 or R7? They are the same and mine is hacked up by a previous owner. Gary W0DVNB |
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Early Drake R7 missing Antenna switch
Does anyone know if I should be expecting my early Drake R7 (S/N 358) to be missing the Antenna selection switch?
This one has no switch and no residual wiring that would have been associated with it. There is a hole in the front panel for it, but this was plugged with a polymer filler that was textured and painted to match the gray wrinkle finish that is on the cabinet. A very distant memory suggests to me that this might have been factory, but I could certainly be in error here. Also, does anyone have an Aluminum panel extrusion for either the TR7 or R7? They are the same and mine is hacked up by a previous owner. Gary W0DVNB |
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Re: Antenna selector switch R7
I use mine all the time. :) Could be the PO fried the splitter and pulled the assembly out to repair it but never got a round tuit....
73 -Jim NU0C On Fri, 23 Apr 2021 20:59:41 -0700 "VE7PS" <ve7ps@...> wrote: Why would somebody ever remove this switch????? OK - it is of little use |
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Re: Antenna selector switch R7
Gary;
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A long time ago, in a world far far away, John Kriner, aka "TR7-dude" on the Bay, had some of these switches.? I bought one for my R-4245 clone, which has been installed but never wired up.? You might check with him to see if he still has any left. Why would somebody ever remove this switch????? OK - it is of little use in most amateur applications....but again, why remove it? 73 Peter VE7PS On 2021-04-23 7:03 p.m., Gary Follett wrote:
Some chucklehead removed the antenna selector switch from this R7 I just acquired. Is there any chance anybody might have one? |
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Re: TR7 with handle on side, power fuse on back
Thank you, someone did send me the instructions.
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Gary W0DVN On Apr 23, 2021, at 6:44 PM, Jerry Kessler <N4JL.cw@...> wrote: |
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Re: TR7 with handle on side, power fuse on back
Keith Erickson
Hi Gary,
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The mobile mounting kit, had a replacement case with a handle. The power cable leads had at the end a enclosure similar to what you describe which indeed could prossibly mointed were the FA7 was intended. I have one. Keith K0gnw On Apr 23, 2021, at 5:21 PM, Gary Follett <xntrick1948@...> wrote: |
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Re: TR7 with handle on side, power fuse on back
Gary,
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I believe you are describing the MMK-7 Kit to make the TR-7 more portable for mobile operation. I may have the instructions somewhere. I'll look if you are have further interest. Jerry, N4JL At 06:27 PM 4/23/2021, you wrote:
I have a TR7 with a handle on its side and a module on the back holding a power fuse for the 13.8 volts. |
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Re: TR7 with handle on side, power fuse on back
Thank you very much. That is very helpful.
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Gary W0DVN On Apr 23, 2021, at 5:46 PM, Joe Pyles <epyles@...> wrote: |
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Re: TR7 with handle on side, power fuse on back
The case with the handle and the power filter were part of the MMK7 mobile mounting kit.
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73, Joe Pyles KC9LAD At 06:27 PM 4/23/2021, you wrote:
I have a TR7 with a handle on its side and a module on the back holding a power fuse for the 13.8 volts. --
This email has been checked for viruses by AVG. |
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TR7 with handle on side, power fuse on back
I have a TR7 with a handle on its side and a module on the back holding a power fuse for the 13.8 volts.
This is factory original but I have never seen this version before. The side handle is the same as that seen on the pS7. The rear fuse module is installed where the FA7 would go. Anyone heard of this version? Gary W0DVN PS: The radio works fine! |
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Re: R4C BFO leakage into 50Khz IF
What a great article!? I've owned several R-4C's -- two of which had strong third mixer problems and it has been obvious to me that the engineers had been chasing a noise problem in that 6EJ7 circuit. One comment, though: he mentions an "early" R-4C but the truly early ones had one less filter position and used a 6BE6 -- much closer to the original designs of the earlier 4-Line.? The first thing I had noticed when I bought a late R-4C was all of that noise from the third mixer of the later one!? The early design didn't have that issue (that I noticed). It would be interesting to see if the earlier, 6BE6 version's specs are, using the same test equipment. Steve Wedge, W1ES/4 Time flies like an arrow.? Fruit flies like a banana. Sent with Secure Email. ‐‐‐‐‐‐‐ Original Message ‐‐‐‐‐‐‐ On Friday, April 23, 2021 10:55 AM, Martin Sole <hs0zed@...> wrote:
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Re: R4C BFO leakage into 50Khz IF
开云体育Lionel:It IS possible that those early 6EJ7 models are prone to this issue.? I just ran out and checked my 22,3xx R-4C and I do see about 2 to 2-1/2 S-units rise on the meter at mid-scale on the passband, relative to the 9 and 3 o'clock positions on that radio.? I do not see ANY change on either the mid-25K or mid-28 K receivers.? I no longer have an early 6HS6 radio, which I miss terribly!? I liked it better than any of them! I have no plans to pull this radio and start dickering with the lead dress - just too many other priorities, and it's a bit of a bear to pull apart as it is part of a TR-44C Comm station.? I do need to work on the late R-4C, as it seems to be suffering from really bad 3rd mixer issues, among others. 73 Peter VE7PS On 2021-04-23 8:43 a.m., Lionel B
wrote:
Peter, the AR forum thread is interesting, and I wonder if I am correct in assuming all 21xxx - 23xxx have the same issue.? |
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Re: R4C BFO leakage into 50Khz IF
开云体育Paul:I don't disagree with you.? Drama is the polite way of putting it.? Rob is not the only one who will turn away a radio.? Ron, WB4HFN, will not work on a modified radio, even if those mods are Sherwood boards.? I don't blame them.? A mis-wired modification can chew up a lot of bench time....hence charges.....in a big hurry, and sometimes with no positive results. His rant did point out that leakage article, which I found quite interesting. 73 Peter VE7PS On 2021-04-23 8:51 a.m., Paul
Christensen wrote:
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Re: R4C BFO leakage into 50Khz IF
开云体育
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Re: R4C BFO leakage into 50Khz IF
Peter, the AR forum thread is interesting, and I wonder if I am correct in assuming all 21xxx - 23xxx have the same issue.?
It seems to be very sensitive to any wiring being moved, like the design is right on the edge where proper design would suggest not using wire placement as a "tuneup" aid.? I like the IF filter leakage article as the blow by around the CW filters has always been annoying, enough so that I talked to Bill Frost long ago (78?) about this issue.? He told me that this was how the design worked and there was no update or mod suggested.? An abundance of food Peter.? tnx. |
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Re: R4C BFO leakage into 50Khz IF
开云体育A very interesting article, but it doesn't address the problem I think Lionel is talking about. The 50 kHz BFO leakage manifests itself as a strong zero-beat signal that peaks as you tune the passband tuning control through the center of its range. My late model R-4C, S/N 28792, certainly shows that problem. I've rewired the 3rd Mixer 6EJ7 to use series feed for the BFO signal as suggested by W5DA many years ago. That mod did seem to help some of the problems with the stage, but also seemed to have the effect of aggravating the BFO leakage. I also installed one of the old Solid Tubes at the third mixer and that seems to have a little more gain, which further exacerbates the problem. I've worked on this on and off for many years, and haven't really found a good solution. I've done a lot of fooling around (scientific term) with the lead dress in the area of the BFO and the 3rd Mixer to mitigate the effect, but it's certainly still there. The good news is that it's only really a problem if you're trying to listen to CW signals with a very low beat note. The crystal filters have sharp enough skirts that tuning the PBT away from zero beat even a little will drop the BFO leakage signal into the noise.On 4/23/2021 10:55 AM, Martin Sole
wrote:
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Re: R4C BFO leakage into 50Khz IF
Martin, this is interesting and I've looked at the work when considering 5695 filter ultimate stopband.? I have also read. yesterday, one ham's report indicating the BFO leakage was actually the much maligned 3rd mixer's products at 5695 (5645 +/- BFO) getting back into the 2nd mixer or via the crystal filter switch wiring. This I have not seen documented except in this one report and if it is the case then it would seem to be much more difficult to fix without SM7EQL's work.
I'm wondering if in the past I just accepted the rise in S-meter at passband control center.? It's been a looong time. |
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Re: R4C BFO leakage into 50Khz IF
开云体育Ha ha:Martin beat me to it as I was writing! 73 Peter VE7PS On 2021-04-23 8:23 a.m., VE7PS via
groups.io wrote:
Lionel: |
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Re: R4C BFO leakage into 50Khz IF
开云体育Lionel:Thanks for the info.....this one got me snooping around a bit. Check out this link first: I cannot reproduce what you see (rise in S-meter reading with passband tuning at 12 o'clock in SSB modes) on my 25,xxx and 28,xxx R-4C's.? I have one more earlier one yet to try.? It IS reported in that thread in another R-4C in the 23,xxx range, which is closer to yours. The really interesting part comes later in the lengthy "Sherwood bashing" dissertation by "Noddy", but he refers to an article I had not seen before here: This article goes into what appears to me as a potential solution to the leakage problem, which you could do in small steps, with measurable results along the way, taking it only as far as one needs to in order to achieve satisfactory performance.? It does get pretty complicated and invasive by the end.? After reading this, I have to wonder if Drake moved some components around to reduce leakage in later production, possibly explaining why I do not see it in my two relatively high serial # radios. Hope that gives you some food for thought. 73, Peter VE7PS On 2021-04-22 12:56 p.m., Lionel B
wrote:
I've seen an article about this topic and unfortunately cannot find the document. The receiver has been "on the shelf" in an air conditioned shack for about 20 years and now I've been going through and aligning per the manual.? When rotating the passband tuning from LSB to USB there is a peak at center that moves the S meter up to about S4 while on either end it falls to S0.? I've had this rx since 1976 and have aligned many times, but this seems new. |
Jim Shorney
Paul Christensen
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