What is needed are detailed specs on the radio before and after if TX use of the filter is planned. I don't see such information published anywhere. I am not saying that the filters are not good quality. I am sure they are. But in a world full of unintended consequences there is not enough information for the technical ham to make an informed decision. Dozens of eHam reviews and user testimonials that say "works great!" notwithstanding. 73 -Jim NU0C On Sun, 11 Apr 2021 17:23:38 +0000 "Tony Deprato" <tony.deprato@...> wrote: Myself and Dale W4OP of PAR Eng.check his restore work .have used Frank's filters.they work and work well. I have them in C lines and TR7 lines.Frank has Sweeps of all his filters on the website. Check them against the old Drake sweeps..73.Tony wa4jqs
Sent via the Samsung GALAXY S? 5, an AT&T 4G LTE smartphone
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Myself and Dale W4OP? of PAR Eng.check his restore work .have used Frank's filters.they work and work well. I have them in C lines and TR7 lines.Frank has Sweeps of all his filters on the website. Check them against the old Drake sweeps..73.Tony wa4jqs?
Sent via the Samsung GALAXY S? 5, an AT&T 4G LTE smartphone
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Exactly! 73 -Jim NU0C On Sun, 11 Apr 2021 09:18:19 -0700 "Jeff Herhold" <jrherhold@...> wrote: A final consideration, of course, is to ensure the filter center frequency is properly set in relation to the carrier frequency to make sure the lowest audio frequencies and opposite sideband are adequately suppressed by the filter skirts. Please do this correctly.
Thanks for all of us,
Jeff, WI7D
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Don¡¯t expect miracles with the NB ! It works on some noise and some it just don¡¯t care! I would eliminate all noise in and around house first!
I run a Timewave dsp599 ( works on audio ) which makes the radio much better to listen to.
My R4C I don¡¯t have a NB in it the first IF is to narrow for stock NB to work but using the Timewave , lightning isnt to bad and I don¡¯t make any rf noise in house or if I do I can turn that light off Hihi
73s Byron AC9PA
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On Apr 11, 2021, at 11:20 AM, wb6ogd <garywinblad@...> wrote: ?The Drake blanker is very effective... Like Richard says it works great on ignition noise. Back in the day it made the difference between being able to hear a station or not. Now a days, there isn't much ignition noise anymore so it really doesn't do much. 73, Gary WB6OGD On 4/11/2021 7:36 AM, Richard Knoppow wrote: I can talk about the R4B. The blanker works fine on ignition noise, which was what it was mostly designed for but does nothing for the grinding line noise that is much more common. I tested it using a Tektronix pulse generator. It does work but is not like the blankers found in some more modern receivers. The idea of the blanker is to prevent pulse noise like ignition noise from causing the AVC to reduce sensitivity. It also does not affect the sort of noise a conventional noise limiter of the sort found in boatanchor receivers will take out but the usual series valve limiter does not work for CW or SSB. I think there are after market noise removers that work pretty well.
On 4/11/2021 5:09 AM, David Lipson via groups.io wrote:
Hi
I,ve been trying to use my r4a recently. The pulse noise has been strong, and the blanker does not seem to be helpful. IS the experience of others similar?
73s
David
N9pvf
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The Drake blanker is very effective...? Like Richard says it works great on ignition noise.
Back in the day it made the difference between being able to hear a station or not.
Now a days, there isn't much ignition noise anymore so it really doesn't do much.
73,
Gary
WB6OGD
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On 4/11/2021 7:36 AM, Richard Knoppow wrote: ?? I can talk about the R4B. The blanker works fine on ignition noise, which was what it was mostly designed for but does nothing for the grinding line noise that is much more common. I tested it using a Tektronix pulse generator. It does work but is not like the blankers found in some more modern receivers. The idea of the blanker is to prevent pulse noise like ignition noise from causing the AVC to reduce sensitivity. It also does not affect the sort of noise a conventional noise limiter of the sort found in boatanchor receivers will take out but the usual series valve limiter does not work for CW or SSB. I think there are after market noise removers that work pretty well.
On 4/11/2021 5:09 AM, David Lipson via groups.io wrote:
Hi
I,ve been trying to use my r4a recently. The pulse noise has been strong, and the blanker does not seem to be helpful. IS the experience of others similar?
73s
David
N9pvf
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A final consideration, of course, is to ensure the filter center frequency is properly set in relation to the carrier frequency to make sure the lowest audio frequencies and opposite sideband are adequately suppressed by the filter skirts. Please do this correctly.
Thanks for all of us,
Jeff, WI7D
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Please disregard this message.? I posted to the wrong group.
Thanks Ryan Scott
The following files have been uploaded to
the Files area of the [email protected] group.
By: Ryan Scott <tweeker42000@...>
Description:
For any of you who attended Stan's sale last month. Here is a detailed inventory list provided to me by Valerie. It will tell you the state of the instrument you received. Thanks, Ryan Scott
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The following files have been uploaded to
the Files area of the [email protected] group.
By: Ryan Scott <tweeker42000@...>
Description:
For any of you who attended Stan's sale last month. Here is a detailed inventory list provided to me by Valerie. It will tell you the state of the instrument you received. Thanks, Ryan Scott
|
I can talk about the R4B. The blanker works fine on ignition noise, which was what it was mostly designed for but does nothing for the grinding line noise that is much more common. I tested it using a Tektronix pulse generator. It does work but is not like the blankers found in some more modern receivers. The idea of the blanker is to prevent pulse noise like ignition noise from causing the AVC to reduce sensitivity. It also does not affect the sort of noise a conventional noise limiter of the sort found in boatanchor receivers will take out but the usual series valve limiter does not work for CW or SSB. I think there are after market noise removers that work pretty well.
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Show quoted text
On 4/11/2021 5:09 AM, David Lipson via groups.io wrote: Hi
I,ve been trying to use my r4a recently. The pulse noise has been strong, and the blanker does not seem to be helpful. IS the experience of others similar?
73s
David
N9pvf
--
Richard Knoppow
1oldlens1@...
WB6KBL
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Hi
I,ve been trying to use my r4a recently. The pulse noise has been strong, and the blanker does not seem to be helpful. IS the experience of others similar?
73s
David?
N9pvf
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I am using the Noble 2K8 filter on my R-4C for several months now and couldn't be happier.
On SSB there is no fiddling on the BFO anymore to decide whether you want it sound optimal on the low or high audio.
The Noble filter brings out everything of human voices and makes the original MS-4 speaker sound very rich.
73 Mark PA5MW
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John, I too ordered from Frank, for the 2.8khz filter and couldn't be happier, I get Great Reports and the Audio I hear is Great! Actually sounds Better (too Me) than my FTDX5000. I also got the W2IHY? EQ plus, hooked it up today and my friends (TV, RF Engineer) and another Drake Nut, told me it was hard to tell the Difference between the TR7A and my 5000 using a ALS?1300 amp and also switching to a L4B and Ten Tec 425 Titan all by flipping a Switch!? That's using a 781 Heil on all radio's. Woody
-- ?  ?Of?all?the things I've Lost, I miss my Mind the Most~~~???
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The same problem can arise with a
DIN socket. Poking a piece of copper wire into
each pin-socket in turn and using a hot iron quickly on a clean
tag worked well.
Michael 2E0IHW
On 10/04/2021 18:04, Evan via groups.io
wrote:
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One "trick" I have ?used is to put a "heatsink clip"
(pointed nose) on each pin that I soldered and that seemed to
help. ?I clipped it on the base if there was room, from ?the
end if there wasn't. ?Worked for me.
Evan, K9SQG
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I should stay out of this and will not comment on either posters statements. However I will add this:
?? The necessary bandwidth for speech and music transmission was studied in detail by Harvey Fletcher and his associates at Bell Labs in the 1930s. Much of that research was published in Harvey's book "Speech and Hearing" which ran several editions. In it he shows charts showing the distribution of power in speech, the effect of frequency bandwidth and cut off on intelligibility and on naturalness. All this was of vital importance to the telephone service. The labs found that the bandwidth for intelligibility was narrower than the bandwidth for "natural" sounding speech. The naturalness was necessary because telephone subscribers demanded it. Somewhat later research published by the Russians found that the bandwidth and dynamic range of speech could be limited to the point where it was no longer possible to distinguish one speaker from another without destroying the intelligence.
?? Minimum bandwidth and minimum power use is often desirable but not always. The desired limits also depend on the amount of noise in the circuit. In quiet circuits wider bandwidth and wider dynamic range generally go with higher articulation but the presence of noise changes this.
?? The statistical nature of speech has been covered in many publications, I think it is worth some study.
--
Richard Knoppow
1oldlens1@...
WB6KBL
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And my post was to caution *all* users that just slamming in a wide filter without giving it any thought is not a good idea. If you don't like that, just delete the message. It's your radio and your neck, you will do what you want. I'm used to technical advice being ignored. That doesn't mean I will stop giving it. Or that it is incorrect and "does not hold water". If you can find a problem with the Drake math, feel free to have at it. It's not rocket science, but it _is_ radio science. Your signal will be wide. That is a fact. 73 -Jim NU0C On Sat, 10 Apr 2021 11:12:26 -0700 "John McGrath" <solutions884@...> wrote: Well Jim you can do your policing to someone else, I knows better there is zero problem with using this as a tx filter. Matter of fact I might even put a 4K in the other one for some ESSB. Your argument is old and holds no water except for transmission on 60 meters which I never operate the rig on anyhow.? So, I will certainly sleep just fine with this filter knowing its one of the best sounding TR7s on ssb. Heck I might even put a small EQ on it.
The post was meant to help folks out if they were looking for some filter options and not pay stupid prices people want for the "drake" filters on ebay or elsewhere.
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Similar?to Evan's procedure, I have used narrow-tipped locking forceps. I've also used those "third hand" helpers with the dual alligator clips.?
One "trick" I have ?used is to put a "heatsink clip" (pointed nose) on each pin that I soldered and that seemed to help.? I clipped it on the base if there was room, from ?the end if there wasn't.? Worked for me.
73,
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Good luck John. I hope it works out for you.
Mike / KE5YTV
On Friday, April 9, 2021, 2:38:05 PM CDT, John Limbach, K8NN <john@...> wrote:
Mike:
Thanks for that.? They're not fully up and running on the site but I did e-mail requesting a quote on the 18Mz 3rd overtone xtal.
de John K8NN
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?Well Jim you can do your policing to someone else, I knows better there is zero problem with using this as a tx filter. Matter of fact I might even put a 4K in the other one for some ESSB. Your argument is old and holds no water except for transmission on 60 meters which I never operate the rig on anyhow.? So, I will certainly sleep just fine with this filter knowing its one of the best sounding TR7s on ssb. Heck I might even put a small EQ on it.?
The post was meant to help folks out if they were looking for some filter options and not pay stupid prices people want for the "drake" filters on ebay or elsewhere.?
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Re: Drake Transmitting Convertors
Tony,
I have bit of? history with problems of getting people to properly "tune" in an SSB signal!
From 1981 to about 2000 I operated the HF radios in a USAF C-141-A/B & C-17B? aircraft? and later (2009-2018)? the HF radios in the Boeing 737-800/900 ETOPS (overwater)? aircraft!.?
The C-141 was equipped with Collins 618T HF radios that operated from 2.000 to 29.999 MHz (USB only) and the Boeing aircraft were equipped with (among others ) the Collins HFS-900 HF radios. (also 2.000 - 29.999 MHz USB-only )?
?
They only "tuned" 1kHz steps and only worked on USB .....LSB was available but not needed because "no one" uses LSB in Aviation/Marine/Military/commercial service,? so it is not provided for selection on the control head.
[Actually the C-17B was equipped with a Collins HF (ARC-190 I think) that would "tune" in 100Hz steps and also had cockpit selectable LSB (WOOHOO!!) ]
All those years (aside from the hassle of getting people on 75 and 40 to actually talk to me on USB ......"What're you doing on the "WRONG" sideband???" )? I had one heck of a time when someone was using an older analog radio getting them to "tune" me in. (there's only one "frequency" where an SSB signal sounds "right"......I can probably tell + or minus about 20-30Hz "off"t)? I routinely had people 50-100Hz off that couldn't or wouldn't try to get closer!!?
It was sometimes a little frustrating!
73/Rick
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John,
Your perception is on track. ?Considering a passive LCR equivalent circuit model of a Quartz crystal mounted in a holder with wire connection leads, the third overtone, the next highest possible resonance after the fundamental, has a lower impedance, purely resistive at resonance, and much, much lower than the nearby parallel resonance, w.r.t. frequency. ?The series resonance occurs first, then as frequency increases slightly beyond series resonance, the crystal becomes inductive with a very high impedance at parallel resonance (again purely resistive), occurring at the fundamental and each valid overtone. ?With increasing overtones, the series resonant impedance (resistance) drops somewhat linearly. ?With the voltage across the crystal being proportional to the crystal impedance, the third overtone will (normally) result in a lower voltage.
Apparently when this radio was designed, these ¡°higher¡± crystal frequencies were generally only available for third overtone. ?Hence, the Colpitts oscillator, using parallel inductance, was used for greater output. ?The third overtone series resonance crystal creates a low impedance in the cathode circuit, only at third overtone resonance resonance to lower negative feedback and increase the gain. ?With the tuned tank circuit in the feedback path, the Colpitts oscillator configuration is realized. ?The 2-B manual couldn¡¯t accurately call this a Colpitts oscillator, because of the use of the low impedance path created by the crystal in the cathode circuit, and apparently didn¡¯t what to take the manual-space to explain it thoroughly (alright with me). ?Even though fundamental frequency crystals are available at these higher frequencies these days, you what to use what the circuit was designed for, the third overtone series resonance (using AT-cut Quartz). ?I will be interested to know the difference in price between an HC-48/U holder and an HC-49/U holder, with 10 ppm crystal frequency accuracy, depending on how WD8DAS quotes your crystal.
Let¡¯s see what the L10 adjustment will do, after checking the circuit wiring. ?Make sure someone before you did not modify the circuit.
73,
Michael Smith, N4KZO
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Jim Shorney
Gary WB6OGD
Ryan Scott