|
Re: SR2000 tech tip. VFO unstable and jumping.
I put a heat deflector between the relay and the six AQ five problem solved. 73 Dave On Sun, May 12, 2024 at 3:43?PM Ki6NQT via <tims566=[email protected]> wrote: That's good to know.?? |
|
Re: HT-44 noise on SSB
¿ªÔÆÌåÓý
When you unplug the mic you remove the load from the front end of the mic amp chain. When you turn the mic gain to max all the noise in the unloaded first mic amp is fed to the second mic amp. The normal range for the mic gain is 2-4 for a crystal mic and
3-5 for a dynamic?mic. Amplified mics should not be used on the 44 or any of the SR series.
Walt Cates, WD0GOF
?
From: [email protected] <[email protected]> on behalf of Floyd - K8AC <floydsense@...>
Sent: Saturday, May 11, 2024 1:33 PM To: [email protected] <[email protected]> Subject: Re: [HallicraftersRadios] HT-44 noise on SSB ?
Walt - I will do what you suggest.? Interesting.? But - the noise is there WITH NO AUDIO INPUT AT ALL.? Unplug the mic, key the PTT and turn up the mic gain.? Noise begins at very low mic gain setting.? With mic gain all the way clockwise, the noise is
strong enough to produce 4 watts of RF output.
Floyd |
|
Re: HT-44 noise on SSB
Walt - I will do what you suggest.? Interesting.? But - the noise is there WITH NO AUDIO INPUT AT ALL.? Unplug the mic, key the PTT and turn up the mic gain.? Noise begins at very low mic gain setting.? With mic gain all the way clockwise, the noise is strong enough to produce 4 watts of RF output.
Floyd |
|
Re: HT-44 noise on SSB
¿ªÔÆÌåÓý
Ok I re-read your email again.
You are most likely over driving the mic amps.
To properly measure the noise level:
1, Inject a 5mv RMS signal into the mic input.
2, Turn the mic gain to minimum.
3, Key up in ssb.
4, Advance the mic gain until you reach saturation and back off about 5%.
5, Unkey, disconnect the audio, and put a 600ohm resistor from the mic audio input pin to gnd.
7, Key up and make the noise measurement.
Walt Cates, WD0GOF
?
From: [email protected] <[email protected]> on behalf of Floyd - K8AC <floydsense@...>
Sent: Saturday, May 11, 2024 10:06 AM To: [email protected] <[email protected]> Subject: Re: [HallicraftersRadios] HT-44 noise on SSB ?
No luck with rivet investigation.? I've done a couple of things that have made noticable improvement, but not solved the problem entirely.? I used this method of measurement to observe the effect of changes I've made:? LSB mode, mic gain fully clockwise,
operation switch set to MOX, ground the PTT line at mic jack (no mic connected).? Before any changes, this resulted in an RF output of 12 watts on the external wattmeter (feeding a dummy load).? That's with the carrier null adjusted for minimum carrier level.??
The first change was to replace the original two coax lines running from the mic amplifier stages to the mic gain control on the front panel.? The original lines were tightly laced into the wire harness running along the right edge of the chassis (as seen from bottom with front panel facing you).? The result of this change was a reduction in the RF output from 12 watts to 8 watts.? The new coax runs are separated from the wire harness as much as possible.? Zip tying them together makes the run stiff enough that it stays in place pretty well. After reading about a similar problem in a different make of transmitter, I examined the routing of the AC wiring from the rear panel connector to the on/off switch.? Once again, the AC carrying wires were laced into the large wiring harness that's routed close to the high gain mic stages.? I replaced that arrangement with a new twisted pair running directly from the rear panel connector to the on/off switch.? This time when I tested the output level, it was only 4 watts.?? At this point, I'm wondering what the observed RF output level might be of other HT-44s, with the mic disconnected, but the mic gain turned up all the way.? Other HT-44 owners - please comment on what you see on your transmitter.?? 73, Floyd |
|
Re: HT-44 noise on SSB
¿ªÔÆÌåÓý
What is the position of your MIC GAIN?
Walt Cates, WD0GOF
?
From: [email protected] <[email protected]> on behalf of Floyd - K8AC <floydsense@...>
Sent: Saturday, May 11, 2024 10:06 AM To: [email protected] <[email protected]> Subject: Re: [HallicraftersRadios] HT-44 noise on SSB ?
No luck with rivet investigation.? I've done a couple of things that have made noticable improvement, but not solved the problem entirely.? I used this method of measurement to observe the effect of changes I've made:? LSB mode, mic gain fully clockwise,
operation switch set to MOX, ground the PTT line at mic jack (no mic connected).? Before any changes, this resulted in an RF output of 12 watts on the external wattmeter (feeding a dummy load).? That's with the carrier null adjusted for minimum carrier level.??
The first change was to replace the original two coax lines running from the mic amplifier stages to the mic gain control on the front panel.? The original lines were tightly laced into the wire harness running along the right edge of the chassis (as seen from bottom with front panel facing you).? The result of this change was a reduction in the RF output from 12 watts to 8 watts.? The new coax runs are separated from the wire harness as much as possible.? Zip tying them together makes the run stiff enough that it stays in place pretty well. After reading about a similar problem in a different make of transmitter, I examined the routing of the AC wiring from the rear panel connector to the on/off switch.? Once again, the AC carrying wires were laced into the large wiring harness that's routed close to the high gain mic stages.? I replaced that arrangement with a new twisted pair running directly from the rear panel connector to the on/off switch.? This time when I tested the output level, it was only 4 watts.?? At this point, I'm wondering what the observed RF output level might be of other HT-44s, with the mic disconnected, but the mic gain turned up all the way.? Other HT-44 owners - please comment on what you see on your transmitter.?? 73, Floyd |
|
Re: HT-44 noise on SSB
No luck with rivet investigation.? I've done a couple of things that have made noticable improvement, but not solved the problem entirely.? I used this method of measurement to observe the effect of changes I've made:? LSB mode, mic gain fully clockwise, operation switch set to MOX, ground the PTT line at mic jack (no mic connected).? Before any changes, this resulted in an RF output of 12 watts on the external wattmeter (feeding a dummy load).? That's with the carrier null adjusted for minimum carrier level.??
The first change was to replace the original two coax lines running from the mic amplifier stages to the mic gain control on the front panel.? The original lines were tightly laced into the wire harness running along the right edge of the chassis (as seen from bottom with front panel facing you).? The result of this change was a reduction in the RF output from 12 watts to 8 watts.? The new coax runs are separated from the wire harness as much as possible.? Zip tying them together makes the run stiff enough that it stays in place pretty well. After reading about a similar problem in a different make of transmitter, I examined the routing of the AC wiring from the rear panel connector to the on/off switch.? Once again, the AC carrying wires were laced into the large wiring harness that's routed close to the high gain mic stages.? I replaced that arrangement with a new twisted pair running directly from the rear panel connector to the on/off switch.? This time when I tested the output level, it was only 4 watts.?? At this point, I'm wondering what the observed RF output level might be of other HT-44s, with the mic disconnected, but the mic gain turned up all the way.? Other HT-44 owners - please comment on what you see on your transmitter.?? 73, Floyd |
|
Re: PS-500A-AC rear pane
¿ªÔÆÌåÓýWalt, ? I¡¯ll give that a try. Thanks for making the images available. ? Paul, W9AC ? From: Walt Cates <cateswa@...>
Sent: Friday, May 10, 2024 6:25 PM To: HALLI IO GROUP <[email protected]>; Paul Christensen <w9ac@...> Subject: PS-500A-AC rear pane ? Simple build your one process. ? ? Then click PS-150/500 REAR PANEL BUILD ? ? Walt Cates, WD0GOF ? A majority of acceptance is not proof of correctness.? |
|
Re: New P2000 Rear panels
¿ªÔÆÌåÓýWell done!? Now I need to get motivated and have one made for my SR-400a supply. ? Paul, W9AC ? From: [email protected] <[email protected]> On Behalf Of W7WRX
Sent: Friday, May 10, 2024 6:04 PM To: [email protected] Subject: [HallicraftersRadios] New P2000 Rear panels ? I had the rear panel for the P2000 remade. ?I was missing one. ?This is the sample artwork on cardboard. ?I found the closest press board I could find and dropped it off today. They will print me a few extras. If anyone wants one let me know know. I am unsure of cost yet. Just reply with your name and how many you want.? |
|
Re: New P2000 Rear panels
Dave Qty 1 On Fri, May 10, 2024 at 6:04?PM W7WRX via <clark=[email protected]> wrote: I had the rear panel for the P2000 remade.? I was missing one.? This is the sample artwork on cardboard.? I found the closest press board I could find and dropped it off today. They will print me a few extras. If anyone wants one let me know know. I am unsure of cost yet. Just reply with your name and how many you want.? |
|
Re: RF Detector Probe
Nice! Kudos. On Thu, May 9, 2024 at 6:16?PM Paul Christensen via <w9ac=[email protected]> wrote: I posted the message below to the Kenwood-Hybrid group but thought the information may be useful here. |
|
RF Detector Probe
I posted the message below to the Kenwood-Hybrid group but thought the information may be useful here.
-------------------------------------------------------------------------------------------------------------------------- A while back there was a discussion concerning RF detector probes.? Since then, I had been looking for a NOS or used Heathkit PK-3 probe but these don't seem to be as common as the Heath PK-1 universal scope probe.? I decided to purchase a PK-1 probe with the intent to convert it into an RF probe and actually made it more functional than the PK-3.? Because the PK-1 comes with a SPDT switch, I use it to my advantage to switch either high or low RF detection sensitivity.? The PK-3 manual gives the builder an option of installing one, or up to three germanium detection diodes.? So, the choice of probe sensitivity is chosen at the time of the build.? With a switch, that decision is no longer a concern.? Using a Dremel tool, I cut new circuit traces on the PK-1 PC board that allows for the switched probe sensitivity.? The input cap can be seen at the lower edge.? It's 0.001 uF NP0 SMD with a 1KV rating.? ?All diodes are 1N60P.? The original design calls for using uninsulated braid for the ground return lead.? I decided to insulate it with blue heat-shrink tubing.? Images attached. Paul, W9AC ? |
|
Re: HT-45 Loudenboomer Value?
On Thu, May 9, 2024 at 12:38 PM, Bill (Group Owner) wrote: Yes, I concur, very nice looking amp, kinda looks "Used very little".Hi Bill, I don't know if you got my email sent to "owner"? But I do have several pictures of my HT-45 PSU build I would like to share for the files/pictures area once I get them all together.? If you would like me to do that, please let me know where to send them or would a shared iCloud or Google files link, ? etc be better? -- 73/Rick W4XA __________________________________ All posts are created using OpenSuSE Leap 15.5 x64 Linux |
Dave Jordan
waltcates
Floyd - K8AC
Paul Christensen
Donald J
Rick W7IMM