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TR7 Audio

jerry-KF6VB All Messages By This Member #81494 One minor audio annoyance with the TR7 - the volume control doesn't go all the way to zero. Instead of a tradition voltage divider pot, they do something with the AGC. So to get the thing to quiet down, I also turn down the RF gain. - Jerry, KF6VB toggle quoted message Show quoted text On 2025-01-01 08:06, Jim Shorney via groups.io wrote: FWIW the TR7 uses an LM380. It works pretty well. On Wed, 1 Jan 2025 10:45:24 -0500 "Mike Bryce via groups.io" <prosolar@...> wrote: FYI… I designed an audio amp board for the R4C that used a LM380. Worked great and had plenty of humph to drive the MS4 speaker to room filling volume -- 73 -Jim NU0C
Frank KG9H Member Profile All Messages By This Member #81495 开云体育 Jerry, When I sold potentiometers with Stackpole Carbon Company, that issue is specified as “hop-off” and specified as a percentage of the resistance. When we sold them to Heath, Electrovoice, Zenith, etc., ?the engineer needed to specify a percentage of hop-off or nothing”. The hop-off actually protected the potentiometer so you never dialed in a zero with current flowing through the resistive area. ? ? ?Frank Krozel ? ? ? ? ? ?KG9H Life Member, ARRL ? ? (630) 924-1600 kg9hfrank@... toggle quoted message Show quoted text On Jan 2, 2025, at 12:14?PM, jerry-KF6VB via groups.io <jerry@...> wrote: One minor audio annoyance with the TR7 - the volume control doesn't go all the way to zero. Instead of a tradition voltage divider pot, they do something with the AGC. ?So to get the thing to quiet down, I also turn down the RF gain. ????????????????- Jerry, KF6VB On 2025-01-01 08:06, Jim Shorney via groups.io wrote: FWIW the TR7 uses an LM380. It works pretty well. On Wed, 1 Jan 2025 10:45:24 -0500 "Mike Bryce via groups.io" <prosolar@...> wrote: FYI… I designed an audio amp board for the R4C that used a LM380. Worked great and had plenty of humph to drive the MS4 speaker to room filling volume -- 73 -Jim NU0C
Steve Wedge, W1ES/4 All Messages By This Member #81496 I thought that the AF pot didn't go all the way to zero.? Back in the day, it would have been easy to sub a different pot set. I like the idea of the RF gain and can't for the life of me understand why I didn't think of that.? I got my ticket in 1982, so the days of most hams "riding the RF gain" were long past and I have my RF gain almost always set to max.? Drake, to a certain extent, also went this way by the C Line (though the TR3/4 was set up the same way) by putting the RF gain on the puny little metal control concentric to the AF gain knob. Steve Wedge, W1ES Time flies like an arrow.? Fruit flies like a banana. Sent with secure email. On Thursday, January 2nd, 2025 at 1:25 PM, kg9hfrank@... via groups.io <kg9hfrank@...> wrote: toggle quoted message Show quoted text Jerry, When I sold potentiometers with Stackpole Carbon Company, that issue is specified as “hop-off” and specified as a percentage of the resistance. When we sold them to Heath, Electrovoice, Zenith, etc., ?the engineer needed to specify a percentage of hop-off or nothing”. The hop-off actually protected the potentiometer so you never dialed in a zero with current flowing through the resistive area. ? ? ?Frank Krozel ? ? ? ? ? ?KG9H Life Member, ARRL ? ? (630) 924-1600 kg9hfrank@... On Jan 2, 2025, at 12:14?PM, jerry-KF6VB via groups.io <jerry@...> wrote: One minor audio annoyance with the TR7 - the volume control doesn't go all the way to zero. Instead of a tradition voltage divider pot, they do something with the AGC. ?So to get the thing to quiet down, I also turn down the RF gain. ????????????????- Jerry, KF6VB On 2025-01-01 08:06, Jim Shorney via groups.io wrote: FWIW the TR7 uses an LM380. It works pretty well. On Wed, 1 Jan 2025 10:45:24 -0500 "Mike Bryce via groups.io" <prosolar@...> wrote: FYI… I designed an audio amp board for the R4C that used a LM380. Worked great and had plenty of humph to drive the MS4 speaker to room filling volume -- 73 -Jim NU0C
Rob Sherwood All Messages By This Member #81508 The R-4C has the same problem. It may go clear back to my original R-4. Rob, NC0B toggle quoted message Show quoted text -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of jerry-KF6VB Sent: Thursday, January 02, 2025 11:15 AM To: [email protected] Cc: Jim Shorney via groups.io Subject: [DRAKE-RADIO] TR7 Audio One minor audio annoyance with the TR7 - the volume control doesn't go all the way to zero. Instead of a tradition voltage divider pot, they do something with the AGC. So to get the thing to quiet down, I also turn down the RF gain. - Jerry, KF6VB On 2025-01-01 08:06, Jim Shorney via groups.io wrote: FWIW the TR7 uses an LM380. It works pretty well. On Wed, 1 Jan 2025 10:45:24 -0500 "Mike Bryce via groups.io" <prosolar@...> wrote: FYI… I designed an audio amp board for the R4C that used a LM380. Worked great and had plenty of humph to drive the MS4 speaker to room filling volume -- 73 -Jim NU0C
Gary Follett All Messages By This Member #81510 开云体育 Later TR7’s did not suffer this problem. It seems the pot was changed to one which got to zero ohms before the click.? Gary W0DVN toggle quoted message Show quoted text On Jan 2, 2025, at 3:44?PM, Rob Sherwood via groups.io <rob@...> wrote: The R-4C has the same problem. It may go clear back to my original R-4. ?Rob, NC0B -----Original Message----- From:?[email protected]?[mailto:[email protected]] On Behalf Of jerry-KF6VB Sent: Thursday, January 02, 2025 11:15 AM To:?[email protected] Cc: Jim Shorney via? Subject: [DRAKE-RADIO] TR7 Audio One minor audio annoyance with the TR7 - the volume control doesn't go? all the way to zero. Instead of a tradition voltage divider pot, they do something with the? AGC. ?So to get the thing to quiet down, I also turn down the RF gain. ?????????????????- Jerry, KF6VB On 2025-01-01 08:06, Jim Shorney via groups.io wrote: FWIW the TR7 uses an LM380. It works pretty well. On Wed, 1 Jan 2025 10:45:24 -0500 "Mike Bryce via groups.io" <prosolar@...> wrote: FYI… I designed an audio amp board for the R4C that used a LM380.? Worked great and had plenty of humph to drive the MS4 speaker to room? filling volume -- 73 -Jim NU0C
Steve Wedge, W1ES/4 All Messages By This Member #81516 My TR7A still has the annoying feature of not going to no signal. Steve Wedge, W1ES Time flies like an arrow.? Fruit flies like a banana. Sent with secure email. On Thursday, January 2nd, 2025 at 4:48 PM, Gary Follett via groups.io <xntrick1948@...> wrote: toggle quoted message Show quoted text Later TR7’s did not suffer this problem. It seems the pot was changed to one which got to zero ohms before the click.? Gary W0DVN On Jan 2, 2025, at 3:44?PM, Rob Sherwood via groups.io <rob@...> wrote: The R-4C has the same problem. It may go clear back to my original R-4. ?Rob, NC0B -----Original Message----- From:?[email protected]?[mailto:[email protected]] On Behalf Of jerry-KF6VB Sent: Thursday, January 02, 2025 11:15 AM To:?[email protected] Cc: Jim Shorney via? Subject: [DRAKE-RADIO] TR7 Audio One minor audio annoyance with the TR7 - the volume control doesn't go? all the way to zero. Instead of a tradition voltage divider pot, they do something with the? AGC. ?So to get the thing to quiet down, I also turn down the RF gain. ?????????????????- Jerry, KF6VB On 2025-01-01 08:06, Jim Shorney via groups.io wrote: FWIW the TR7 uses an LM380. It works pretty well. On Wed, 1 Jan 2025 10:45:24 -0500 "Mike Bryce via groups.io" <prosolar@...> wrote: FYI… I designed an audio amp board for the R4C that used a LM380.? Worked great and had plenty of humph to drive the MS4 speaker to room? filling volume -- 73 -Jim NU0C
Jim Shorney All Messages By This Member #81525 In the commercial 2-way radio business this was a feature, not a bug. Kept the dispatcher from turning the volume all the way down either accidentally or on purpose. On Thu, 2 Jan 2025 15:48:10 -0600 "Gary Follett via groups.io" <xntrick1948@...> wrote: Later TR7’s did not suffer this problem. It seems the pot was changed to one which got to zero ohms before the click. Gary W0DVN On Jan 2, 2025, at 3:44?PM, Rob Sherwood via groups.io <rob@...> wrote: The R-4C has the same problem. It may go clear back to my original R-4. Rob, NC0B -----Original Message----- From: [email protected] <mailto:[email protected]> [mailto:[email protected]] On Behalf Of jerry-KF6VB Sent: Thursday, January 02, 2025 11:15 AM To: [email protected] <mailto:[email protected]> Cc: Jim Shorney via groups.io <> Subject: [DRAKE-RADIO] TR7 Audio One minor audio annoyance with the TR7 - the volume control doesn't go all the way to zero. Instead of a tradition voltage divider pot, they do something with the AGC. So to get the thing to quiet down, I also turn down the RF gain. - Jerry, KF6VB -- 73 -Jim NU0C
Tony Yamin All Messages By This Member #81527 I've seen instruction manuals where you adjust the AF gain to a 'comfortable' level and use the RF gain as a volume knob.? I learned to operate this way in my early days and, as I understand, it helps keep the RF noise out-of-the-radio! ? -- TNX-n-73's fer now.... KF6JS - Tony
Evan All Messages By This Member #81535 I learned this as a new novice from my mentor, since "Elmer" was out of style. ?It helps to reduce the effects of lightning and QRM. 73, Evan, ?K9SQG On Friday, January 3, 2025 at 12:21:28 AM EST, Tony Yamin <tony92646@...> wrote: I've seen instruction manuals where you adjust the AF gain to a 'comfortable' level and use the RF gain as a volume knob.? I learned to operate this way in my early days and, as I understand, it helps keep the RF noise out-of-the-radio! ? -- TNX-n-73's fer now.... KF6JS - Tony
rls19 All Messages By This Member #81537 开云体育 This technique was developed originally for receivers that did not?have product detectors. Envelope detection is much?more sensitive to the ratio of local oscillator level versus signal level,?so the signal level going into the second mixer had to?be kept low enough?for proper demodulation by "riding" the RF gain control. 73, Bob AD3K toggle quoted message Show quoted text From: [email protected] <[email protected]> on behalf of Evan via groups.io <k9sqg@...> Sent: Friday, January 3, 2025 11:05 AM To: [email protected] <[email protected]> Subject: Re: [DRAKE-RADIO] TR7 Audio ? I learned this as a new novice from my mentor, since "Elmer" was out of style. ?It helps to reduce the effects of lightning and QRM. 73, Evan, ?K9SQG On Friday, January 3, 2025 at 12:21:28 AM EST, Tony Yamin <tony92646@...> wrote: I've seen instruction manuals where you adjust the AF gain to a 'comfortable' level and use the RF gain as a volume knob.? I learned to operate this way in my early days and, as I understand, it helps keep the RF noise out-of-the-radio! ? -- TNX-n-73's fer now.... KF6JS - Tony
Steve Wedge, W1ES/4 All Messages By This Member #81539 Yes. The RFG control isn’t nearly as important on most receivers that were purpose-built for SSB — i.e., with product detectors.? I’ll sometimes play with the RFG during contests but rarely otherwise.? Steve Wedge, W1ES Time flies like an arrow. Fruit flies like a banana. Sent from for iOS toggle quoted message Show quoted text On Fri, Jan 3, 2025 at 11:46, rls19 via groups.io <rls19@...> wrote: This technique was developed originally for receivers that did not?have product detectors. Envelope detection is much?more sensitive to the ratio of local oscillator level versus signal level,?so the signal level going into the second mixer had to?be kept low enough?for proper demodulation by "riding" the RF gain control. 73, Bob AD3K From: [email protected] <[email protected]> on behalf of Evan via groups.io <k9sqg@...> Sent: Friday, January 3, 2025 11:05 AM To: [email protected] <[email protected]> Subject: Re: [DRAKE-RADIO] TR7 Audio ? I learned this as a new novice from my mentor, since "Elmer" was out of style. ?It helps to reduce the effects of lightning and QRM. 73, Evan, ?K9SQG On Friday, January 3, 2025 at 12:21:28 AM EST, Tony Yamin <tony92646@...> wrote: I've seen instruction manuals where you adjust the AF gain to a 'comfortable' level and use the RF gain as a volume knob.? I learned to operate this way in my early days and, as I understand, it helps keep the RF noise out-of-the-radio! ? -- TNX-n-73's fer now.... KF6JS - Tony
Jim Shorney All Messages By This Member #81563 Well, it actually does make a signal more listenable by reducing the noise floor. On Fri, 03 Jan 2025 17:04:01 +0000 "Steve Wedge, W1ES/4 via groups.io" <w1es@...> wrote: Yes. The RFG control isn’t nearly as important on most receivers that were purpose-built for SSB — i.e., with product detectors. I’ll sometimes play with the RFG during contests but rarely otherwise. Steve Wedge, W1ES Time flies like an arrow. Fruit flies like a banana. Sent from [Proton Mail]() for iOS On Fri, Jan 3, 2025 at 11:46, rls19 via groups.io <[rls19@...](mailto:On Fri, Jan 3, 2025 at 11:46, rls19 via groups.io <<a href=)> wrote: This technique was developed originally for receivers that did not have product detectors. Envelope detection is much more sensitive to the ratio of local oscillator level versus signal level, so the signal level going into the second mixer had to be kept low enough for proper demodulation by "riding" the RF gain control. 73, Bob AD3K --------------------------------------------------------------- From: [email protected] <[email protected]> on behalf of Evan via groups.io <k9sqg@...> Sent: Friday, January 3, 2025 11:05 AM To: [email protected] <[email protected]> Subject: Re: [DRAKE-RADIO] TR7 Audio I learned this as a new novice from my mentor, since "Elmer" was out of style. It helps to reduce the effects of lightning and QRM. 73, Evan, K9SQG On Friday, January 3, 2025 at 12:21:28 AM EST, Tony Yamin <tony92646@...> wrote: I've seen instruction manuals where you adjust the AF gain to a 'comfortable' level and use the RF gain as a volume knob. I learned to operate this way in my early days and, as I understand, it helps keep the RF noise out-of-the-radio! -- TNX-n-73's fer now.... KF6JS - Tony -- 73 -Jim NU0C
John K5MO All Messages By This Member #81566 40m cw at night in a big contest is a good time to rediscover the rf gain. :) John k5mo

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