Re: R4C 1500hz crystal filter damaged
Lionel, Possible solution FWIW:
Pull the pin out of the case to the position you want it
Do some careful horizontal surface scoring near the base of the pin (small file, nail file, etc.) - don't go too deep and compromise the integrity of the pin!
Epoxy around the base of the pin over the horizontal scoring with JB Weld
Let the JB Weld cure for the full recommended time.
The goal is to have the JB Weld fill into the scoring and "grip" the pin from receding back into the filter case.
I have used this on pin replacements, using brass nails, in classic car dashboard circuit boards that serviced plug in connectors and have had 100% success.
- Steve? W7SJT "Always look for a positive solution then Improvise, Adapt, and Overcome" - Adaptation of the U.S. Marine Corps motto
"There are no rules here!...We're trying to accomplish something!!"
- Thomas Edison
"Success is not final, failure is not fatal.? It is the courage to continue that counts." -?Winston Churchill
On Monday, March 20, 2023 at 03:10:06 PM MDT, Lionel B <n5lb@...> wrote:
One of the pins is pushed back into the filter case. I can gently pull it back into position but have found no way to secure the pin from outside of the case.
I have tried various cements, epoxy, super glue without success.? The pin will always push in as the filter is plugged into the socket.? It seems a lost cause.??
Has anyone encountered this problem?? Is it now a throw away filter???
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Re: R4C 1500hz crystal filter damaged
Which OEM made the filter? ?Rob, NC0B
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On Mar 20, 2023, at 3:09 PM, Lionel B <N5LB@...> wrote:
?One of the pins is pushed back into the filter case. I can gently pull it back into position but have found no way to secure the pin from outside of the case.
I have tried various cements, epoxy, super glue without success.? The pin will always push in as the filter is plugged into the socket.? It seems a lost cause.??
Has anyone encountered this problem?? Is it now a throw away filter???
|
R4C 1500hz crystal filter damaged
One of the pins is pushed back into the filter case. I can gently pull it back into position but have found no way to secure the pin from outside of the case.
I have tried various cements, epoxy, super glue without success.? The pin will always push in as the filter is plugged into the socket.? It seems a lost cause.??
Has anyone encountered this problem?? Is it now a throw away filter???
|
Gary,
?I did the same thing but I found the bright white to look the best in my 4C line. However, I was not using the same style bulb. It is convenient to use the bayonet style though as it is just a bulb swap. I bought both warm and white LED's and I have generally used the white. Although the original incandescent bulbs were very yellow, the white LED's filtered through the blue seemed to look better. I guess it is a matter of taste and also most are used to what the incandescent looked like.
Here is something similar to what I used -
https://www.amazon.com/EverBright-10-Pack-Replacement-Pinball-Chipsets/dp/B084RMC8CL/ref=sr_1_15
?
Doug, WA3DSP
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Re: DRAKE TECHNICAL NET UPDATE ( March 19, 2023 )
I'm in south central Montana and can only hear the net down in the noise on 40 - unintelligible.
The Collins group has a weekly net on 20 meters that I can easily copy on the high end of 20.
Suggestion: How about a 20 meter Drake Tech Net on 14.238 Mhz (or somewhere close)? Same day, same time or same day, different time?
- Steve? W7SJT "Always look for a positive solution then Improvise, Adapt, and Overcome" - adaptation of the U.S. Marine Corps motto
"There are no rules here!...We're trying to accomplish something!!"
- Thomas Edison
"Success is not final, failure is not fatal.? It is the courage to continue that counts." -?Winston Churchill
?
On Monday, March 20, 2023 at 01:01:41 PM MDT, Rick WA6III <myr748@...> wrote:
On Sun, Mar 19, 2023 at 02:11 PM, M Gilger wrote:
WB0IQK
I would sure like to participate in a 40m "Drake Net" but I cannot hear anyone on the above net. There doesn't seem to be one (40M) reachable from the West Coast.? There is some sort of a Drake net on 75m but they all seem to be SOCAL based.? Usually pretty weak and noisy in the pacific Northwest. Has anyone considered a late afternoon 40m group/net that might be more accessable to the NW (UT, ID, MT, WA, OR) etc? --
73/Rick
WA6III
*Every post is created using Linux
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Re: DRAKE TECHNICAL NET UPDATE ( March 19, 2023 )
On Sun, Mar 19, 2023 at 02:11 PM, M Gilger wrote:
WB0IQK
I would sure like to participate in a 40m "Drake Net" but I cannot hear anyone on the above net. There doesn't seem to be one (40M) reachable from the West Coast.? There is some sort of a Drake net on 75m but they all seem to be SOCAL based.? Usually pretty weak and noisy in the pacific Northwest. Has anyone considered a late afternoon 40m group/net that might be more accessable to the NW (UT, ID, MT, WA, OR) etc? --
73/Rick
WA6III
*Every post is created using Linux
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I was really disappointed in the looks of my old #47 bulbs in my 4A line so I changed the bulbs out for LEDs finally.
Not only do they keep the front of the radio so much cooler, the looks are so much improved.
I bought the wrong LEDs, they were cool white and not frosted.? A few minutes with some sandpaper and a yellow
Sharpie fixed them up though.
My iPhone didn't capture the look very well, they look even better in person.? All the original Lagoon Blue filters
are still fine.
73,
Gary
WB6OGD
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Re: R4B 50 Khz I.F. sweep.
Hi Dave!
I use an Elecraft K3 with a P3 daily, and when I refurbished my old(ish) B-twins a few years ago I wanted to see the effect of the variable passband filtering, so that meant looking at the 50 kHz IF.? I used a small impedance buffer preamp mounted under the chassis of the R-4B near the 50 kHz amp V5 feeding an SMA in the 'Spare' jack position on the rear skirt and feed an .? It was the only one I could find which went below 100 kHz, indeed it will receive as low as 500 Hz.
Of course there are issues: the 50 kHz LO feeds through to V5 and shows up as a constant peak in the display, but that is a minor complaint.? In general it works well, but those of us spoiled by steep crystal filters and DSP IFs, or in my case the will find the resulting passband shape factor to be somewhat...lumpy may be a good word?? I have been a broadcast engineer for 40 years and have serviced more FM transmitters (I love my old Gates FM-1H!), receivers and ham gear than I care to remember so although I will not claim to be the most expert RF aligner, I do have a passing familiarity with RF and IF alignment.? This being said, I ran through a full alignment as per the manual and the receiver works gangbusters.? Sensitivity is on par with my K3 but sounds SOOOO much better and the analog passband tuner is a thing of beauty compared to the DSP filtering in the K3 which gets harsher the more narrow you squeeze it.? Despite this fine performance, the 50 kHz IF passband shape is still not as nice as a crystal filter...I'll bet NC0B would see much better results on his modded R-4C, still it is nice to be able to see the band activity on my PC, it is usable and fun to see.
Cheers & 73,
Howie / WA4PSC
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Re: R4B 50 Khz I.F. sweep.
Boy that was a fast response thanks guys for the tips. The SA I have is a Rigol 815TG? which is the same unit WA8SAJ uses so figured I was good to go unfortunately I'm a little new to spectrum analyzers' operation. The first test I did was the 5645 Khz sweep with the SA connected through a blocking cap to pin1-V2 then used a small coil of insulated wire to basically sniff on the underside of V3. There was enough signal to draw a pattern on the SA seemed to work really well. Think I will revisit the 5645 test again without a direct connection to see if there's any difference in SA response.?
?In regards to the 50Khz test, I was directly connecting the TG through a blocking cap in multiple places without success, and from what you all said this is the wrong test setup to use. Was also using a blocking cap for the SA input as well I will refine my connections and report back as long as I can find the right test points for TG and SA input.
Dave
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Re: R4B 50 Khz I.F. sweep.
For my single conversion Hammarlund alignments I make extensive use of an SA - the Hammarlund folks at the factory were funny about that. Anyway, any of the new generation SA's like Siglent, Rigol, etc., will sweep +/- 50 kHz.
For the HQ's I loosely couple in around the insulated wire feeding the mixer and sample out by connecting around an insulated wire feeding the detector. No direct probe to tube pin connections. Safe and minimal to no loading of the circuit.
Don't have an R-4B nor a schematic but, in general, I'd repeat my Hammarlund connection scheme and suggest injecting 50 kHz at the 2nd mixer and tapping off the return signal at the diode detectors? Should work.
Loose coupling as Rob suggests is the goal, like clamping around an insulated wire.
I'd never make a direct metal to probe connection with a sensitive SA, or at least not without a very good reason and first thoroughly characterizing the connection point with a multimeter.
Dan
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On Mar 19, 2023, at 8:39 PM, Rob Sherwood <rob@...> wrote:
?
When I sweep something like this I feed in the tracking generator signal, preferably a stage before, through with around a 10k resistor. ?The I preferably use an FET probe to pick off the signal that goes back into the spectrum analyzer. ?A 10X passive probe
may work but the termination will be wrong. ?
You likely won’t be able to measure the ultimate rejection of the filter, but you can see the passband shape you are possibly tweaking. ?
Rob, NC0B
On Mar 19, 2023, at 6:25 PM, W6MQI via groups.io <w6mqi@...> wrote:
?Guess I should mention I have the exact same spectrum analyzer as WA8SAJ used in his test.
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Re: R4B 50 Khz I.F. sweep.
I have a 3585B. A beautiful instrument. I also have a 8594E with TG and narrowband options that is a bit more portable. It's spec-ed down to 9 KHz but I've never pushed it that low. My NanoVNA claims coverage to 50KHz. Might work OK on a Drake low IF. 73 -Jim NU0C On Mon, 20 Mar 2023 00:39:54 +0000 "Rob Sherwood" <rob@...> wrote: I use an HP 3585A which is good from audio through 40 MHz. Rob, NC0B
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Re: R4B 50 Khz I.F. sweep.
I use an HP 3585A which is good from audio through 40 MHz. Rob, NC0B
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On Mar 19, 2023, at 6:31 PM, Jim Shorney <jimNU0C@...> wrote:
?
50 KHz is hard. Most analyzers that could fall into ham hands don't go down that far. I have an old HP that goes down to 20 Hz but it would anchor a decent size boat.
73
-Jim
NU0C
On Sun, 19 Mar 2023 17:17:32 -0700
"W6MQI via groups.io" <w6mqi@...> wrote:
Has anyone ever tried to sweep the 50Khz I.F. in the R4B with a spectrum analyzer? WA8SAJ had a powerpoint presentation a few years ago showing screenshots using his SA to sweep the 50 Khz I.F., but he gave no real explanation of how he performed the test and adjustments for the passband curves. I have tried to reproduce his SA sweeps without success just can't seem to find the right input for the tracking generator and output from the R4B to the SA input. Anyone have success performing this procedure?
Dave
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Re: R4B 50 Khz I.F. sweep.
When I sweep something like this I feed in the tracking generator signal, preferably a stage before, through with around a 10k resistor. ?The I preferably use an FET probe to pick off the signal that goes back into the spectrum analyzer. ?A 10X passive probe
may work but the termination will be wrong. ?
You likely won’t be able to measure the ultimate rejection of the filter, but you can see the passband shape you are possibly tweaking. ?
toggle quoted message
Show quoted text
On Mar 19, 2023, at 6:25 PM, W6MQI via groups.io <w6mqi@...> wrote:
?Guess I should mention I have the exact same spectrum analyzer as WA8SAJ used in his test.
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Re: R4B 50 Khz I.F. sweep.
50 KHz is hard. Most analyzers that could fall into ham hands don't go down that far. I have an old HP that goes down to 20 Hz but it would anchor a decent size boat. 73 -Jim NU0C On Sun, 19 Mar 2023 17:17:32 -0700 "W6MQI via groups.io" <w6mqi@...> wrote: Has anyone ever tried to sweep the 50Khz I.F. in the R4B with a spectrum analyzer?? WA8SAJ had a powerpoint presentation a few years ago showing screenshots using his SA to sweep the 50 Khz I.F., but he gave no real explanation of how he performed the test and adjustments for the passband curves. I have tried to reproduce his SA sweeps without success just can't seem to find the right input for the tracking generator and output from the R4B to the SA? input.? Anyone have success performing this procedure?
Dave
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Re: R4B 50 Khz I.F. sweep.
Guess I should mention I have the exact same spectrum analyzer as WA8SAJ used in his test.
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?
Has anyone ever tried to sweep the 50Khz I.F. in the R4B with a spectrum analyzer?? WA8SAJ had a powerpoint presentation a few years ago showing screenshots using his SA to sweep the 50 Khz I.F., but he gave no real explanation of how he performed the test and adjustments for the passband curves. I have tried to reproduce his SA sweeps without success just can't seem to find the right input for the tracking generator and output from the R4B to the SA? input.? Anyone have success performing this procedure?
Dave
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I think this is an example of the "real hams" make their own cables claim many like to make, he's just making an allowance for the elderly and handicapped... Ken, N2VIP
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On Mar 19, 2023, at 17:36, Jim W7RY via groups.io <jimw7ry@...> wrote:
?
At what age does elderly start??
Are you sure they wont sell them to the young or non handicapped?
Just askin...
Jim W7RY
On 3/19/2023 5:26 PM, Gregory Beat via
groups.io wrote:
Elderly or handicapped radio amateur can buy pre-made cables for
Drake?4-line Twins or Collins S-line?
from Joel at RF Connection (Gaithersburg,
MD)
RG-58 or RG-62 coax cable (you request).
<424FE80E-0C4C-4199-BD55-78BA72409F81.jpeg>
--
Thanks and 73, Jim W7RY
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At what age does elderly start??
Are you sure they wont sell them to the young or non handicapped?
Just askin...
Jim W7RY
On 3/19/2023 5:26 PM, Gregory Beat via
groups.io wrote:
Elderly or handicapped radio amateur can buy pre-made cables for
Drake?4-line Twins or Collins S-line?
from Joel at RF Connection (Gaithersburg,
MD)
RG-58 or RG-62 coax cable (you request).
--
Thanks and 73, Jim W7RY
|
Elderly or handicapped radio amateur can buy pre-made cables for Drake?4-line Twins or Collins S-line? from Joel at RF Connection ( Gaithersburg, MD)RG-58 or RG-62 coax cable (you request). 
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DRAKE TECHNICAL NET UPDATE ( March 19, 2023 )
Today we had 31 stations checking into the net on 7.238. It was a bit rough with the Virginia QSO part?going on, but we made it through with little difficulty.?
The following radio's were used to check in.?
Twins = 10 TR4(x) = 5 TR5 = 1 TR7(x) = 5
73's, Mark, WB0IQK
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Rob Sherwood
Doug Crompton WA3DSP
Gary WB6OGD
W6MQI
Jim Shorney
Greg W9GB