Re: DRAKE MN-2000 Ceramic wafer replacement/repair for Antenna Selector Switch help?
I see now that both sides of the switch are tied together (presumably to enhance the power capability of the switch) which may complicate finding a replacement.? I think someone mentioned using two wafers to mimic that but, again, finding one replacement may be hard enough to do and even harder to find two.? :-(
Thanks,
Barry - N4BUQ
From: "Peter A" <christinepeterarsenault@...>
To: "DRAKE-RADIO" <[email protected]>
Sent: Monday, March 13, 2023 3:20:06 PM
Subject: Re: [DRAKE-RADIO] DRAKE MN-2000 Ceramic wafer replacement/repair for Antenna Selector Switch help?
On Mon, Mar 13, 2023 at 04:53 PM, n4buq wrote:
Isn't that just a ceramic Centralab wafer?? Those can often be found as individual wafers on eBay, etc., with the correct shaft hole and contacts/wiper configuration.? The trick is getting the proper stud spacing.? I had to replace a few of those in a VTVM last year and it took a while to find a proper replacements but I finally found them.
?
Good luck with it.
I do believe it is one of their wafers but difficult to find the exact.
I was in touch with an Ebay seller who sells this type of thing and in all his inventory he had no match.
Thanks for the input Barry.
73
Peter
VE9KX
?
?
Thanks,
Barry - N4BUQ
?
From: "Peter A" <christinepeterarsenault@...>
To: "DRAKE-RADIO" <[email protected]>
Sent: Monday, March 13, 2023 10:16:32 AM
Subject: [DRAKE-RADIO] DRAKE MN-2000 Ceramic wafer replacement/repair for Antenna Selector Switch help?
[Edited Message Follows]
Hello to all.? It's been a minute since posting here but I keep up to date on what's up just the same.? Always interesting and informative.? This spring will be Delhi tower antenna erection, and hopefully get some of my Drake stuff on the air!? Difficulty deciding on a "multiband beam".? Either the Hy-gain TH-11DX or Optibeam OB9-HD5.? Anyway I'll figure it out eventually I guess.? Now to the point of this post.? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? Wondering if anyone has an MN-2000?antenna switch?ceramic wafer they want to part with"? Previous owner "hot switched" and fried a few
contacts.? I've removed the wafer over the weekend.? I tried the ebay seller "networkrw" and he was very hopeful he could help, but it didn't pan out as he couldn't find one close enough.
Contacted Ron Wb4hfn but he said he didn't have that part.? Any ideas of where to source something suitable even with a little modification?
I understand that a replacement was available from Russia but I doubt that's not an option at this point.
I'd appreciate any info that may help.? I know about the direction of "drilling out" the rivets and swapping contacts with another wafer and using very small bolts to hold them in but is this the only option available, and I'm not even sure the contact plates would be good enough anyway?
I've looked at the older posts asking the same question but they're limited.
Any ideas would be greatly appreciated.
73
Peter
VE9KX
|
Re: What are the differances between the T4X and the T4XB
On Mon, 13 Mar 2023, Rob Sherwood wrote: The major change was 8-pole TX filters instead of 4 pole. Then the T-4XC came out with "locked transceive" which had never existed previously. (Meaning there was not an RX vs. TX frequency error.) Rob, NC0B Well that is interesting. That explains why a casual glance at the photographs on eBay do not show any differences. I have a T4XB so, by your desription, it is the better bargain. I also have a C line but that is a waste since I have all the skill and ambition of the Saksatchewan farmers I knew as a schoolboy who parked their Galaxy Vs on 3785kHz and chatted to their friends down the road every night. -- Richard Loken VE6BSV : "...underneath those tuques we wear, Athabasca, Alberta Canada : our heads are naked!" ** rlloken@... ** : - Arthur Black
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Re: DRAKE MN-2000 Ceramic wafer replacement/repair for Antenna Selector Switch help?
On Mon, Mar 13, 2023 at 04:53 PM, n4buq wrote:
Isn't that just a ceramic Centralab wafer?? Those can often be found as individual wafers on eBay, etc., with the correct shaft hole and contacts/wiper configuration.? The trick is getting the proper stud spacing.? I had to replace a few of those in a VTVM last year and it took a while to find a proper replacements but I finally found them.
?
Good luck with it.
I do believe it is one of their wafers but difficult to find the exact. I was in touch with an Ebay seller who sells this type of thing and in all his inventory he had no match. Thanks for the input Barry. 73 Peter VE9KX
?
?
Thanks,
Barry - N4BUQ
?
From: "Peter A" <christinepeterarsenault@...>
To: "DRAKE-RADIO" <[email protected]>
Sent: Monday, March 13, 2023 10:16:32 AM
Subject: [DRAKE-RADIO] DRAKE MN-2000 Ceramic wafer replacement/repair for Antenna Selector Switch help?
[Edited Message Follows]
Hello to all.? It's been a minute since posting here but I keep up to date on what's up just the same.? Always interesting and informative.? This spring will be Delhi tower antenna erection, and hopefully get some of my Drake stuff on the air!? Difficulty deciding on a "multiband beam".? Either the Hy-gain TH-11DX or Optibeam OB9-HD5.? Anyway I'll figure it out eventually I guess.? Now to the point of this post.? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? Wondering if anyone has an MN-2000?antenna switch?ceramic wafer they want to part with"? Previous owner "hot switched" and fried a few
contacts.? I've removed the wafer over the weekend.? I tried the ebay seller "networkrw" and he was very hopeful he could help, but it didn't pan out as he couldn't find one close enough.
Contacted Ron Wb4hfn but he said he didn't have that part.? Any ideas of where to source something suitable even with a little modification?
I understand that a replacement was available from Russia but I doubt that's not an option at this point.
I'd appreciate any info that may help.? I know about the direction of "drilling out" the rivets and swapping contacts with another wafer and using very small bolts to hold them in but is this the only option available, and I'm not even sure the contact plates would be good enough anyway?
I've looked at the older posts asking the same question but they're limited.
Any ideas would be greatly appreciated.
73
Peter
VE9KX
|
Re: DRAKE MN-2000 Ceramic wafer replacement/repair for Antenna Selector Switch help?
Isn't that just a ceramic Centralab wafer?? Those can often be found as individual wafers on eBay, etc., with the correct shaft hole and contacts/wiper configuration.? The trick is getting the proper stud spacing.? I had to replace a few of those in a VTVM last year and it took a while to find a proper replacements but I finally found them.
Good luck with it.
Thanks,
Barry - N4BUQ
From: "Peter A" <christinepeterarsenault@...>
To: "DRAKE-RADIO" <[email protected]>
Sent: Monday, March 13, 2023 10:16:32 AM
Subject: [DRAKE-RADIO] DRAKE MN-2000 Ceramic wafer replacement/repair for Antenna Selector Switch help?
[Edited Message Follows]
Hello to all.? It's been a minute since posting here but I keep up to date on what's up just the same.? Always interesting and informative.? This spring will be Delhi tower antenna erection, and hopefully get some of my Drake stuff on the air!? Difficulty deciding on a "multiband beam".? Either the Hy-gain TH-11DX or Optibeam OB9-HD5.? Anyway I'll figure it out eventually I guess.? Now to the point of this post.? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? Wondering if anyone has an MN-2000?antenna switch?ceramic wafer they want to part with"? Previous owner "hot switched" and fried a few
contacts.? I've removed the wafer over the weekend.? I tried the ebay seller "networkrw" and he was very hopeful he could help, but it didn't pan out as he couldn't find one close enough.
Contacted Ron Wb4hfn but he said he didn't have that part.? Any ideas of where to source something suitable even with a little modification?
I understand that a replacement was available from Russia but I doubt that's not an option at this point.
I'd appreciate any info that may help.? I know about the direction of "drilling out" the rivets and swapping contacts with another wafer and using very small bolts to hold them in but is this the only option available, and I'm not even sure the contact plates would be good enough anyway?
I've looked at the older posts asking the same question but they're limited.
Any ideas would be greatly appreciated.
73
Peter
VE9KX
|
Re: What are the differances between the T4X and the T4XB
The major change was 8-pole TX filters instead of 4 pole. Then the T-4XC came out with "locked transceive" which had never existed previously. (Meaning there was not an RX vs. TX frequency error.) Rob, NC0B
toggle quoted message
Show quoted text
-----Original Message----- From: [email protected] [mailto: [email protected]] On Behalf Of Richard Loken Sent: Monday, March 13, 2023 12:19 PM To: drake mail list Subject: [DRAKE-RADIO] What are the differances between the T4X and the T4XB The subject says it all: what did Drake change when they went from the T4X and the T4XB? Was there a T4XA? -- Richard Loken VE6BSV : "...underneath those tuques we wear, Athabasca, Alberta Canada : our heads are naked!" ** rlloken@... ** : - Arthur Black
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Re: Puzzling problem with the AGC in my R4-C
Hi Bill,
?
It was possible to get the MC1496 mixer to work as far as conversion gain.? The later chip options were simpler to implement.
?
Assuming the Drake AGC circuit hasn¡¯t been changed, most of the attack distortion has been minimized with the NE602 mixer.? That said, I always wanted a slower
AGC decay than Drake offered, so my custom AGC switch implementation had 5 choices (including the almost useless Fast option).?? Unless dealing with QRN, I almost always used the new slowest decay speed on SSB.? To my picky ears the R-4C audio was fine, assuming
the terrible stock audio amp had also been replaced. (Note: I have retired and am not trying to sell a Sherwood AMP-4 module!)
?
I suppose there may still be some distortion during AGC attack since by definition the gain of the radio is changing in a few milliseconds.? One could define
this as distortion.? In a similar way Dynamic Noise Reduction in modern radios is always a tradeoff between reducing noise and living with DSP artifacts.? With my Icom I never run noise reduction on SSB above 2 out of 10 since the digital artifacts annoy me
more than the noise.? That of course is a subjective statement while others run NR as high as 8 out of 10.?
?
I have operated 20 out of the top 25 transceivers on my website table in contests, and only Icom and possibly Kenwood offers a slow enough AGC decay to suite
my operating preferences.? Those brands that are still too fast on SLOW are Apache, Elecraft, Flex and Yaesu. This isn¡¯t necessarily an AGC attack distortion issue as simply me not liking band noise to be as loud as the station I am listening to if the person
speaking pauses for a fraction of a second.
?
On the other hand with at least the Yaesu FT-710, if the AGC is on AUTO, on CW the AGC attack distortion is absolutely terrible.? Are design engineers deaf??
I just don¡¯t get it, or do OEMs only listen to their radios in the lab with a signal generator and not on the air?? Why didn¡¯t Drake notice that there wasn¡¯t AGC attack distortion in the original R-4 but in later R-4As and the follow-on ?products the audio
had seriously degraded??
?
Maybe radio OEMs should have a Hi Fi person with ¡°golden ears¡± on their staff !?? Hi Hi
?
73, Rob, NC0B ?
?
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Show quoted text
From: [email protected] [mailto:[email protected]]
On Behalf Of Bill Leonard N0CU
Sent: Monday, March 13, 2023 9:48 AM
To: [email protected]
Subject: Re: [DRAKE-RADIO] Puzzling problem with the AGC in my R4-C
?
Rob,
Thanks for sharing your insights on this.
What I think you are saying is that AGC attack distortion is a ¡°feature¡± of some of the designs in the receivers by Collins and Drake, and that this distortion increases as the decay time is reduced (which is what I am seeing). Also, the time constants used
for the fast decays are off from what you recommend.
I don¡¯t operate CW so the distortion I am seeing with the M and F settings is not an operational issue for me. However, the engineer in me wants to fix the AGC if something is broken and it is not operating as designed. What I have concluded from your comments
is that this is not the case.
What I failed to mention is that I have installed your NE602 product detector. I didn¡¯t mention it because I didn¡¯t suspect it could be a contributor to an AGC problem. So, did this detector mod eliminate the AGC attack distortion, or only reduce it.
As an aside, before I built and installed your NE602 product detector I tried a 1496 mixer circuit that I had laying around from a previous project. The conversion gain was so much lower
than the original design that it was not a viable option.
--
Bill N0CU
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Re: DRAKE MN-2000 Ceramic wafer replacement/repair for Antenna Selector Switch help?
On Mon, Mar 13, 2023 at 12:51 PM, VE7PS wrote:
Peter:
?
First...a small correction...not THE previous owner...but A previous owner.
?
Contact Paul Kramer, K0UYA, for his picture set on how he replaced that switch with a stripped down multiple section heavy duty 5 pos switch bought?on E-bay?cheaply from Eastern Europe.? I just checked?and there is a Bulgarian seller that seems to have several that would work,? You do need to make up a new shaft extender with the correct "flat" offsets - not too difficult.
?
Paul's address is;
He will likely see this e-mail?anyways.
?
73
Peter
VE7PS
For sure Peter!!? Thanks for the correction.? I worded that wrong. I'll contact Paul and ask for some guidance on that. I do have alternatives now to this unit but I don't want to part it out because of the antenna switch alone. Thanks for the tip. 73 Peter VE9KX
?
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What are the differances between the T4X and the T4XB
The subject says it all: what did Drake change when they went from the
T4X and the T4XB? Was there a T4XA?
--
Richard Loken VE6BSV : "...underneath those tuques we wear,
Athabasca, Alberta Canada : our heads are naked!"
** rlloken@... ** : - Arthur Black
|
On Mon, Mar 13, 2023 at 10:46 AM, John K5MO wrote:
Do you have the pushbutton in the TUNE position?
Yes, with both Fixed Feq buttopns out. RB
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Hi Rick
Do you have the pushbutton in the TUNE position?? When I do (and with both fixed freq buttons OUT) the tuning on my RV75 is slower than the TR7 itself....I'd say maybe 10 degrees of knob motion for? 100 hz? change in the TR7 display
John K5MO
On Mon, Mar 13, 2023 at 1:23?PM Rick Boswell < frboswell@...> wrote: I began checking out a new-to-me RV75 this AM and am seeing some issues I dont yet understand. These are:
1. While the RV75 seems to be working in a basic fashion, the frequency displayed on the TR7 varies by as much a 2 KHz over time, even with an extneded warmup and without touching the tuning knob.
2. It is nearly impossible to set the frequenciny to the desired 100 Hz increment; very small movements of the tuning knob produce a few hundred Hz change in the displayed frequency.
3. The "Fixed Frequency" feature does not display the programmed frequency. Programming is a bit convoluted but I have verified several times that the switch settings are as described in the manual.
This is a a late serial number RV75 in very nice overall condition and was serviced by Ron Baker in 2015; his invoice shows only minimal work needed. My TR7 works as expected with an RV7 in place of the RV75.
So, wondering how best to proceed. Problems may be pilot error due to lack of familiarity, but if so, not clear what the pilot is doing wrong. I have a manual? but am reluctant to dive into troubleshooting without a better understanding as to what might cause these symptoms. Any guidance appreciated.
Rick
K8EZB?
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Re: Cinch Jones connector identification
Greg,
Thanks for your detaioled reply. I did find what looks like to correct connector on eBay.
Rick
K8EZB
|
I began checking out a new-to-me RV75 this AM and am seeing some issues I dont yet understand. These are:
1. While the RV75 seems to be working in a basic fashion, the frequency displayed on the TR7 varies by as much a 2 KHz over time, even with an extneded warmup and without touching the tuning knob.
2. It is nearly impossible to set the frequenciny to the desired 100 Hz increment; very small movements of the tuning knob produce a few hundred Hz change in the displayed frequency.
3. The "Fixed Frequency" feature does not display the programmed frequency. Programming is a bit convoluted but I have verified several times that the switch settings are as described in the manual.
This is a a late serial number RV75 in very nice overall condition and was serviced by Ron Baker in 2015; his invoice shows only minimal work needed. My TR7 works as expected with an RV7 in place of the RV75.
So, wondering how best to proceed. Problems may be pilot error due to lack of familiarity, but if so, not clear what the pilot is doing wrong. I have a manual? but am reluctant to dive into troubleshooting without a better understanding as to what might cause these symptoms. Any guidance appreciated.
Rick
K8EZB?
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Hi Folks, Can anyone here write back and tell me the height of TR7 boards.? I am building sets of extender boards and need that dimension. Also, if there are technicians here willing to test my extender sets, please write back. Tu & 73 John WA1ESO@...401-624-4576
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Re: DRAKE MN-2000 Ceramic wafer replacement/repair for Antenna Selector Switch help?
Peter:
First...a small correction...not THE previous owner...but A previous owner.
Contact Paul Kramer, K0UYA, for his picture set on how he replaced that switch with a stripped down multiple section heavy duty 5 pos switch bought?on E-bay?cheaply from Eastern Europe.? I just checked?and there is a Bulgarian seller that seems to have several that would work,? You do need to make up a new shaft extender with the correct "flat" offsets - not too difficult.
Paul's address is; He will likely see this e-mail?anyways.
73 Peter VE7PS
There is a company on the east coast of ?the US that rebuilds switches. ? Not cheap though. ? Can't ?recall the name of the company.
-----Original Message-----
From: Peter A < christinepeterarsenault@...>
To: [email protected]
Sent: Mon, Mar 13, 2023 11:16 am
Subject: [DRAKE-RADIO] DRAKE MN-2000 Ceramic wafer replacement/repair for Antenna Selector Switch help?
[Edited Message Follows]
Hello to all.? It's been a minute since posting here but I keep up to date on what's up just the same.? Always interesting and informative.? This spring will be Delhi tower antenna erection, and hopefully get some of my Drake stuff on the air!? Difficulty deciding on a "multiband beam".? Either the Hy-gain TH-11DX or Optibeam OB9-HD5.? Anyway I'll figure it out eventually I guess.? Now to the point of this post.? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? Wondering if anyone has an MN-2000? antenna switch?ceramic wafer they want to part with"? Previous owner "hot switched" and fried a few contacts.? I've removed the wafer over the weekend.? I tried the ebay seller " networkrw" and he was very hopeful he could help, but it didn't pan out as he couldn't find one close enough. Contacted Ron Wb4hfn but he said he didn't have that part.? Any ideas of where to source something suitable even with a little modification? I understand that a replacement was available from Russia but I doubt that's not an option at this point. I'd appreciate any info that may help.? I know about the direction of "drilling out" the rivets and swapping contacts with another wafer and using very small bolts to hold them in but is this the only option available, and I'm not even sure the contact plates would be good enough anyway?
I've looked at the older posts asking the same question but they're limited.
Any ideas would be greatly appreciated.
73
Peter
VE9KX
|
Re: Puzzling problem with the AGC in my R4-C
Rob,
Thanks for sharing your insights on this.
What I think you are saying is that AGC attack distortion is a ¡°feature¡± of some of the designs in the receivers by Collins and Drake, and that this distortion increases as the decay time is reduced (which is what I am seeing). Also, the time constants used for the fast decays are off from what you recommend.
I don¡¯t operate CW so the distortion I am seeing with the M and F settings is not an operational issue for me. However, the engineer in me wants to fix the AGC if something is broken and it is not operating as designed. What I have concluded from your comments is that this is not the case.
What I failed to mention is that I have installed your NE602 product detector. I didn¡¯t mention it because I didn¡¯t suspect it could be a contributor to an AGC problem. So, did this detector mod eliminate the AGC attack distortion, or only reduce it.
As an aside, before I built and installed your NE602 product detector I tried a 1496 mixer circuit that I had laying around from a previous project. The conversion gain was so much lower than the original design that it was not a viable option.
-- Bill N0CU
|
Re: DRAKE MN-2000 Ceramic wafer replacement/repair for Antenna Selector Switch help?
There is a company on the east coast of ?the US that rebuilds switches. ? Not cheap though. ? Can't ?recall the name of the company.
-----Original Message-----
From: Peter A <christinepeterarsenault@...>
To: [email protected]
Sent: Mon, Mar 13, 2023 11:16 am
Subject: [DRAKE-RADIO] DRAKE MN-2000 Ceramic wafer replacement/repair for Antenna Selector Switch help?
[Edited Message Follows]
Hello to all.? It's been a minute since posting here but I keep up to date on what's up just the same.? Always interesting and informative.? This spring will be Delhi tower antenna erection, and hopefully get some of my Drake stuff on the air!? Difficulty deciding on a "multiband beam".? Either the Hy-gain TH-11DX or Optibeam OB9-HD5.? Anyway I'll figure it out eventually I guess.? Now to the point of this post.? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? Wondering if anyone has an MN-2000? antenna switch?ceramic wafer they want to part with"? Previous owner "hot switched" and fried a few contacts.? I've removed the wafer over the weekend.? I tried the ebay seller " networkrw" and he was very hopeful he could help, but it didn't pan out as he couldn't find one close enough. Contacted Ron Wb4hfn but he said he didn't have that part.? Any ideas of where to source something suitable even with a little modification? I understand that a replacement was available from Russia but I doubt that's not an option at this point. I'd appreciate any info that may help.? I know about the direction of "drilling out" the rivets and swapping contacts with another wafer and using very small bolts to hold them in but is this the only option available, and I'm not even sure the contact plates would be good enough anyway?
I've looked at the older posts asking the same question but they're limited.
Any ideas would be greatly appreciated.
73
Peter
VE9KX
|
Thanks Gregory. ?Without a pic, hard to know what a vendor is selling.
-----Original Message-----
From: Gregory Beat via groups.io <w9gb@...>
To: [email protected]
Sent: Mon, Mar 13, 2023 9:24 am
Subject: Re: [DRAKE-RADIO] DIN connectors
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DRAKE MN-2000 Ceramic wafer replacement/repair for Antenna Selector Switch help?
Hello to all.? It's been a minute since posting here but I keep up to date on what's up just the same.? Always interesting and informative.? This spring will be Delhi tower antenna erection, and hopefully get some of my Drake stuff on the air!? Difficulty deciding on a "multiband beam".? Either the Hy-gain TH-11DX or Optibeam OB9-HD5.? Anyway I'll figure it out eventually I guess.? Now to the point of this post.? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? Wondering if anyone has an MN-2000?antenna switch?ceramic wafer they want to part with"? Previous owner "hot switched" and fried a few
contacts.? I've removed the wafer over the weekend.? I tried the ebay seller "networkrw" and he was very hopeful he could help, but it didn't pan out as he couldn't find one close enough.
Contacted Ron Wb4hfn but he said he didn't have that part.? Any ideas of where to source something suitable even with a little modification?
I understand that a replacement was available from Russia but I doubt that's not an option at this point.
I'd appreciate any info that may help.? I know about the direction of "drilling out" the rivets and swapping contacts with another wafer and using very small bolts to hold them in but is this the only option available, and I'm not even sure the contact plates would be good enough anyway?
I've looked at the older posts asking the same question but they're limited.
Any ideas would be greatly appreciated.
73
Peter
VE9KX
|
You can detune using a clip-lead jumper. Much safer and stable.?
Steve Wedge, W1ES/4
Time flies like an arrow. Fruit flies like a banana.
Sent from Proton Mail for iOS
On Mon, Mar 13, 2023 at 01:59, Doug Crompton WA3DSP < wa3dsp@...> wrote: Somehow this discussion got off on measuring plate current, which makes no sense since there is already a means of checking cathode current using the two cathode resistors. In any case, my issue was definitely the shunt resistor, which had elevated to 9 ohms but physically looked OK! Replaced with three parallel 10 ohm 1/2 watt resistors and now get good cathode current readings.
The two cathode resistors in my unit had been changed to 10 ohm 2W and they measure very close to that and equal. Unfortunately, my brand-new tubes are not balanced, one has? .2 volts and the other .35 volts across their respective resistors or 20ma ans 35ma. I am going to check my stock for more 6JB6's and hopefully I can find a better match. How much of a difference is a problem? Also checked the screen resistors and they are closely matched so I don't think anyhing other than the tubes themselves would be causing the unbalance.
One problem I see is considerable power drop off on the higher bands. How much CW output should a good T4XC produce? I get 110W on 80 meters but down to about 60W or less on 40 and less even less on higher bands. I suspect the 12BY7 driver and I am going to look for one of them in my stock also. I have a 12.6mhz crystal but it apparently is not working as I get no drive on 160. Another thing to check.
Once I am confident that it is not a tube issue, I will do a complete alignment. I have a question about the RF and Mixer stage alignment procedure in section 5-8 of the manual. Item c-5 and c-6 refer to detuning by putting a screwdriver on the rotor. This seems like a weird way to do things. Has anyone come up with a better approach. Also, item c-5 says to tune the front injection trimmer, while item c-6 says to tune the rear injection trimmers - note plural. There are 4 trimmers, does that mean to tune the 3 rear trimmers? Perhaps someone has a better way of doing this?
Doug, WA3DSP
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Rob Sherwood
Greg W9GB