Re: [Drakelist] TR-7 Question
I think a foolproof way to identify a real TR7A is to look at the cable from the mic input to the spare phono plug at the back.When this is done at the factory this cable is well and truly embedded in the wiring harness and is certainly not a last minute add on. John GI3KDR. From: Ron Baker wb4...@comcast.net To: RadiosRUs radiogu...@hotmail.com; drakelist@zerobeat.net Sent: Thursday, 25 June, 2009 3:48:06 PM Subject: Re: [Drakelist] TR-7 Question Pete, the quick answer to both questions is yes. Unfortunately Drake, when they were liquidating their inventory, sold to anyone that wanted them, the top front panel section which indicated the TR-7A. I have personally seen those panels placed on very early TR7's with serial numbers in the 1000 range and we know the TR7A appeared around serial number 10,600. So in some cases purchasing a TR7A is a buyer beware. I wrote an article on how to identify the model differences for that very reason. Drake did in fact put the serial number in two places, on the rear panel and on the inside, front side of the front sub panel. It is major surgery to get to that area which is why most folks would not attempt. But to prove a point, it is one of several way to identify the exact model. Ron / WB4HFN From: drakelist-boun...@zerobeat.net [mailto:drakelist-boun...@zerobeat.net] On Behalf Of RadiosRUs Sent: Thursday, June 25, 2009 10:14 AM To: drakelist@zerobeat.net Subject: [Drakelist] TR-7 Question In looking at one of the recent auction sites I note that a TR-7A is listed as being authentic. The proof was to take off the front panel and demonstrate that a S/N behind the panel matched the S/N on the back of the radio. Just a curiosity and perhaps for those of us new to the list, has there been a case of counterfeit TR-7A's? Is that something that those of us unfamiliar with past history should be aware of. Has there been some attempt to pass off bogus TR-7A'a as genuine? Thanks Pete N6QW___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] TR-7 Question
Wow, Jim, with that fine idea, and a laser to cut the s/n through the front panel to the extrusion, hummm maybe we can finance both our retirements HI HI 73, Don, WB5HAK ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
[Drakelist] TR-7 Question
In looking at one of the recent auction sites I note that a TR-7A is listed as being authentic. The proof was to take off the front panel and demonstrate that a S/N behind the panel matched the S/N on the back of the radio. Just a curiosity and perhaps for those of us new to the list, has there been a case of counterfeit TR-7A's? Is that something that those of us unfamiliar with past history should be aware of. Has there been some attempt to pass off bogus TR-7A'a as genuine? Thanks Pete N6QW___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] TR-7 Question
Pete, the quick answer to both questions is yes. Unfortunately Drake, when they were liquidating their inventory, sold to anyone that wanted them, the top front panel section which indicated the TR-7A.I have personally seen those panels placed on very early TR7's with serial numbers in the 1000 range and we know the TR7A appeared around serial number 10,600. So in some cases purchasing a TR7A is a buyer beware. I wrote an article on how to identify the model differences for that very reason. Drake did in fact put the serial number in two places, on the rear panel and on the inside, front side of the front sub panel. It is major surgery to get to that area which is why most folks would not attempt. But to prove a point, it is one of several way to identify the exact model. Ron / WB4HFN _ From: drakelist-boun...@zerobeat.net [mailto:drakelist-boun...@zerobeat.net] On Behalf Of RadiosRUs Sent: Thursday, June 25, 2009 10:14 AM To: drakelist@zerobeat.net Subject: [Drakelist] TR-7 Question In looking at one of the recent auction sites I note that a TR-7A is listed as being authentic. The proof was to take off the front panel and demonstrate that a S/N behind the panel matched the S/N on the back of the radio. Just a curiosity and perhaps for those of us new to the list, has there been a case of counterfeit TR-7A's? Is that something that those of us unfamiliar with past history should be aware of. Has there been some attempt to pass off bogus TR-7A'a as genuine? Thanks Pete N6QW ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] TR-7 Question
Ron, I don't disagree with in some cases purchasing a TR7A is a buyer beware. But I must say that IF the TR-7 has had all the modifications that upgrade a TR-7 to a TR-7A, the only remaining significant difference is the use of a '1496 balanced modulator in the 2nd IF/Audio board rather than the diode detector. For all the other changes, Drake supplied the components and installation instructions free of charge. What a company! 73, Tom, AG9X On Thu, Jun 25, 2009 at 9:48 AM, Ron Bakerwb4...@comcast.net wrote: Pete, the quick answer to both questions is yes. Unfortunately Drake, when they were liquidating their inventory, sold to anyone that wanted them, the top front panel section which indicated the TR-7A. I have personally seen those panels placed on very early TR7's with serial numbers in the 1000 range and we know the TR7A appeared around serial number 10,600. So in some cases purchasing a TR7A is a buyer beware. I wrote an article on how to identify the model differences for that very reason. Drake did in fact put the serial number in two places, on the rear panel and on the inside, front side of the front sub panel. It is major surgery to get to that area which is why most folks would not attempt. But to prove a point, it is one of several way to identify the exact model. Ron / WB4HFN ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] TR-7 Question
Tom, You are right, physically there is no real difference between a late, loaded TR7 and TR7A, but the dealers get a real premium for that A label, so one should get what he pays for, hi. I liked Drake's policy of an old front panel replace with the identical, so that wasn't a problem till late. 73, Don, WB5HAK ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] TR-7 Question
On Thu, 25 Jun 2009 21:32:05 -0500, Don Cunningham wrote: You are right, physically there is no real difference between a late, loaded TR7 and TR7A, but the dealers get a real premium for that A label, so one should get what he pays for, hi. I wonder why no one is selling a mini-silkscreen kit on e-pay, with just the letter A in the proper font size with a little bottle of white paint. Hmmm, maybe I'm on to something here. -Jim -- Ham Radio NU0C Lincoln, Nebraska, U.S.S.A. TR7/RV7/R7A/L7, TR6/RV6, T4XC/R4C/L4B, NCL2000, SB104A, R390A, GT550A/RV550A, HyGain 3750, IBM PS/2 - all vintage, all the time! Give a man a URL, and he will learn for an hour; teach him to Google, and he will learn for a lifetime. HyGain 3750 User's Group - http://groups.yahoo.com/group/HyGain_3750/ http://radiojim.exofire.net http://incolor.inetnebr.com/jshorney http://www.nebraskaghosts.org ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] TR-7 Question
Dave - T/R problems are often associated with the 10R and 10T control lines and their fuses, Q306 and Q307. Check both busses, marked on the parent board traces. Each must be very close to +10 when receiving or transmitting respectively AND very close to 0V inversely. You'll probably find that the 10R bus does NOT go to zero in transmit as it should. Q306 and Q307 are on the Transmit Exciter board. If you don't have a Service Manual, you'll need help finding them. Let us know. 73, Garey - K4OAH Glen Allen, VA Drake 2-B, 4-B, C-Line TR-4/C Service Supplement CDs www.k4oah.com [EMAIL PROTECTED] wrote: Hi Gents, I recently acquired my first TR-7 (thank you Evan K9SQG for sharing and thank you Gary W8PU for some technical guidance in finding a shorted pin diode). When I transmit on phone, I'm getting some garbled audio fed back into both the headphones and the external speaker connected via the rear panel. It's very distracting and makes it difficult to talk normally. Audio reports from distant stations say my transmitted audio (Shure 444D) is fine. I'm using a Steppir 2L, so I don't have a bunch of RF running around the shack and the mic gain is set to just kick the ALC in on peaks. The garbled audio is also present transmitting into a dummy load. I'm using an Astron 35A power supply. Using the same exact set-up (coax cable, speaker, speaker connection cable, power supply, etc.) with my Tentec Orion, it's perfectly clean. Any thoughts/suggestions? 73, Dave / K8JDC ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
[Drakelist] TR-7 Question
Hi Gents, I recently acquired my first TR-7 (thank you Evan K9SQG for sharing and thank you Gary W8PU for some technical guidance in finding a shorted pin diode). When I transmit on phone, I'm getting some garbled audio fed back into both the headphones and the external speaker connected via the rear panel. It's very distracting and makes it difficult to talk normally. Audio reports from distant stations say my transmitted audio (Shure 444D) is fine. I'm using a Steppir 2L, so I don't have a bunch of RF running around the shack and the mic gain is set to just kick the ALC in on peaks. The garbled audio is also present transmitting into a dummy load. I'm using an Astron 35A power supply. Using the same exact set-up (coax cable, speaker, speaker connection cable, power supply, etc.) with my Tentec Orion, it's perfectly clean. Any thoughts/suggestions? 73, Dave / K8JDC ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] TR-7 Question
Dave, Has anyone answered your question?? It sounds like the transmit/receive switch transistor problem that Garey Barrell helped me through with a couple of TR7's. If you haven't received any answers, I'll dig out my service manual and guide you through the checks and fix. 73, Don, WB5HAK ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] TR-7 Question
On Wed, 10 Dec 2008 15:33:08 -0500, [EMAIL PROTECTED] wrote: When I transmit on phone, I'm getting some garbled audio fed back into both the headphones and the external speaker connected via the rear panel. It might help a little if you better define garbled - is it distorted but understandable, or does it sound like SSB as recieved on an AM-only reciever? Does it happen on a dummy load as well as an antenna? Is your station well grounded, low VSWR, etc.? Different rigs have different sensitivities to RF in the shack, so comparing it to the Tentec isn't really that helpful :) In the meantime, have a look here: http://www.zerobeat.net/drakelist/tr7moremods.html Item #1, and possibly #4, may have some bearing on this issue. 73 -Jim NU0C ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
