Re: TinySA Ultra 50 Khz as a signal generator
For the DMM (voltmeter) are you attaching to the DC level of the AGC or possibly the downconverted IF signal in the first IF?? The DMM will not see RF energy at the IF frequency.?
Also, most AGCs I've played with are at high impedance DC levels.? The DMM must present a high-Z in measuring the DC AGC voltage.
Just a few thoughts......
Dave - W?LEV
Something else to check is does the agc voltage change with the RF Gain control?
73
Jeff G8HUL
________________________________________
From: [email protected] <[email protected]> on behalf of G8HUL via <g8hul=[email protected]>
Sent: Saturday, May 24, 2025 17:12
To: [email protected] <[email protected]>
Subject: Re: [tinysa] TinySA Ultra 50 Khz as a signal generator
?Does the agc voltage on the multi-meter change with the generator off?
I can only conclude from what the S meter is doing that the generator level is too high even at minimum, but that does not explain what you are seeing on the multi-meter, (assuming that the reading does not change between generator on and off).
73
Jeff G8HUL
________________________________________
From: [email protected] <[email protected]> on behalf of enriqueeeeee2001 via <enriqueeeeee2001=[email protected]>
Sent: Saturday, May 24, 2025 14:36
To: [email protected] <[email protected]>
Subject: Re: [tinysa] TinySA Ultra 50 Khz as a signal generator
Yes, I have checked several times that the signal is injected, I can heard the tone and adjust T17 for zero beat.The probe is in the correct location, although the manual indicates two white/green wires attached in the? 1st IF board, real ones are brown/white.?I attach a photo indicating the places where the voltmeter and generator are)?Now the S-meter goes down to scale (both tiny and HP).?Yes, the S-meter is at zero when the generator is off?I have also checked that neither external antenna is connected nor rx tuned a strong station.[X]
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Re: TinySA Ultra 50 Khz as a signal generator
What does the S meter do with the additional attenuation? Dose it still say at full scale? Jeff ________________________________________ From: [email protected] < [email protected]> on behalf of enriqueeeeee2001 via groups.io <enriqueeeeee2001@...> Sent: Saturday, May 24, 2025 17:45 To: [email protected] < [email protected]> Subject: Re: [tinysa] TinySA Ultra 50 Khz as a signal generator No , it does not change the voltage when the generator is off.?I have just tried placing a 30 db attenuator in the probe but same results. I have also added a toggle switch attenuator ,100 db, and no movement at all.??[X]
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Re: TinySA Ultra 50 Khz as a signal generator
No , it does not change the voltage when the generator is off.
?
I have just tried placing a 30 db attenuator in the probe but same results. I have also added a toggle switch attenuator ,100 db, and no movement at all.
?
?
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Re: TinySA Ultra 50 Khz as a signal generator
Something else to check is does the agc voltage change with the RF Gain control? 73 Jeff G8HUL ________________________________________ From: [email protected] < [email protected]> on behalf of G8HUL via groups.io <g8hul@...> Sent: Saturday, May 24, 2025 17:12 To: [email protected] < [email protected]> Subject: Re: [tinysa] TinySA Ultra 50 Khz as a signal generator Does the agc voltage on the multi-meter change with the generator off? I can only conclude from what the S meter is doing that the generator level is too high even at minimum, but that does not explain what you are seeing on the multi-meter, (assuming that the reading does not change between generator on and off). 73 Jeff G8HUL ________________________________________ From: [email protected] < [email protected]> on behalf of enriqueeeeee2001 via groups.io <enriqueeeeee2001@...> Sent: Saturday, May 24, 2025 14:36 To: [email protected] < [email protected]> Subject: Re: [tinysa] TinySA Ultra 50 Khz as a signal generator Yes, I have checked several times that the signal is injected, I can heard the tone and adjust T17 for zero beat.The probe is in the correct location, although the manual indicates two white/green wires attached in the? 1st IF board, real ones are brown/white.?I attach a photo indicating the places where the voltmeter and generator are)?Now the S-meter goes down to scale (both tiny and HP).?Yes, the S-meter is at zero when the generator is off?I have also checked that neither external antenna is connected nor rx tuned a strong station.[X]
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Re: TinySA Ultra 50 Khz as a signal generator
Does the agc voltage on the multi-meter change with the generator off? I can only conclude from what the S meter is doing that the generator level is too high even at minimum, but that does not explain what you are seeing on the multi-meter, (assuming that the reading does not change between generator on and off). 73 Jeff G8HUL ________________________________________ From: [email protected] < [email protected]> on behalf of enriqueeeeee2001 via groups.io <enriqueeeeee2001@...> Sent: Saturday, May 24, 2025 14:36 To: [email protected] < [email protected]> Subject: Re: [tinysa] TinySA Ultra 50 Khz as a signal generator Yes, I have checked several times that the signal is injected, I can heard the tone and adjust T17 for zero beat.The probe is in the correct location, although the manual indicates two white/green wires attached in the? 1st IF board, real ones are brown/white.?I attach a photo indicating the places where the voltmeter and generator are)?Now the S-meter goes down to scale (both tiny and HP).?Yes, the S-meter is at zero when the generator is off?I have also checked that neither external antenna is connected nor rx tuned a strong station.[X]
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Re: TinySA Ultra 50 Khz as a signal generator
Yes, I have checked several times that the signal is injected, I can heard the tone and adjust T17 for zero beat.
The probe is in the correct location, although the manual indicates two white/green wires attached in the? 1st IF board, real ones are brown/white.
?
I attach a photo indicating the places where the voltmeter and generator are)
?
Now the S-meter goes down to scale (both tiny and HP).
?
Yes, the S-meter is at zero when the generator is off
?
I have also checked that neither external antenna is connected nor rx tuned a strong station.
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Re: TinySA Ultra 50 Khz as a signal generator
The alignment in question if for the 50kHz IF of the Drake Rx. Unfortunately the manual does not give an i/p level for this step, just set it such that there is a slight deflection in the agc voltage. It could be that both generators have too high an o/p level, but that does not tie in with the OP's statement that the agc voltage does not change, unless I have misunderstood what he is saying and the agc changes when the generators are turned on, but not when cores are adjusted. 73 Jeff G8HUL ________________________________________ From: [email protected] < [email protected]> on behalf of Mike EI9FEB <ei9feb@...> Sent: Saturday, May 24, 2025 08:53 To: [email protected] < [email protected]> Subject: Re: [tinysa] TinySA Ultra 50 Khz as a signal generator The HP209A is used in applications likely wanting -20 dBm to +10dBm.The RF input of a communications receiver might be -110dBm (AGC at max gain, signal just above noise) and about -80dBm to -70dBm for S9 on a signal meter.Wikipedia:"S9 for the HF bands to be a receiver input power of -73 dBm. This is a level of 50 microvolts at the receiver's antenna input assuming the input impedance of the receiver is 50 ohms "Also -73dBm is 30dBuV on 50 Ohms. Often receiver sensitivity is in microvolts at 10dB S/N, though in dBuV in the service/alignment manual. Typical uV (not dBm or dBuV) is over 30 at 100 kHz AM, 3 for SSB and as low as 0.1 UHF SSB. FM is usually more sensitive than AM for 10 db S/N and SSB maybe 30x to 50x more sensitive than AM.I use a 30dB attenuator on the TinySA basic and up to 100 dB on my Rigol tracking generator (fixed 30 dB and a 0 to 70dB that has 10dB steps).Has your Drake 50 kHz rather than 100 kHZ minimum RF in, or is 50 kHz the IF? Note the aerial connection is 50 Ohms, but connections to the IF should be high impedance or you detune it. Plenty of Drake receivers do have a 50 kHz IF.
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Re: TinySA Ultra 50 Khz as a signal generator
Are you positive that you are a) injecting signal, and b) probing, in the correct locations? Also you said that the S meter went to full scale, does this happen with both the TinySA and the HP generator, is so at what o/p setting. I assume that the S meter is at zero with the generators connected but off. I assume that you do not have the Rx tuned to a strong station. 73 Jeff g8hul ________________________________________ From: [email protected] < [email protected]> on behalf of enriqueeeeee2001 via groups.io <enriqueeeeee2001@...> Sent: Friday, May 23, 2025 21:13 To: [email protected] < [email protected]> Subject: Re: [tinysa] TinySA Ultra 50 Khz as a signal generator Yes, but the issue is that whatever the output level is there is no a slight deflection , it remains stuck always in 1,6 volts. I have tried with? all levels that the Tiny gives. Right now? I attach photos with -110? -71 and -23 this happen in the two SPR4's that I have.?[X][X][X]
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Re: TinySA Ultra 50 Khz as a signal generator
I read the manual. The lowest RF on the Drake SPR4 is 150 kHz.
Sensitivity (i.e. before AGC reduces gain) at 10dB (S+N)/N is 0.25uV SSB/CW/RTTY (i.e. BFO mode) and 0.5 uV AM
0.5 uV is -113 dBmW
Wikipedia:
"S9 for the HF bands to be a receiver input power of -73 dBm. This is a level of 50 microvolts at the receiver's antenna input assuming the input impedance of the receiver is 50 ohms "
The 50 kHz is the 2nd IF.
Looks like a 1950s valve set, but it is 1970s and transistors.
Crystal tuned, each tuning a 500 kHz band. Factory supplied with 10 crystals, covering most broadcast bands. Adding optional 13 crystals provides 150 kHz - 30 MHz coverage. Continuous coverage with optional FS-4 frequency synthesizer (which is likely noisy).
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Re: NOISE GENERATOR for the HOME BREWERS
I recall a really simple noise generator circuit from a magazine (something like Practical Wireless, in the U.K.) in the 1970s which used a reverse biased green LED, two 9V batteries in series, a pot and one more fixed resistor. I built it at the time. You just tweaked the pot until you found the spot where the noise took off, it certainly worked up to the 2m band. I don¡¯t have it or the schematic any more though sadly.
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Re: TinySA Ultra 50 Khz as a signal generator
The HP209A is used in applications likely wanting -20 dBm to +10dBm.
The RF input of a communications receiver might be -110dBm (AGC at max gain, signal just above noise) and about -80dBm to -70dBm for S9 on a signal meter.
Wikipedia:
"S9 for the HF bands to be a receiver input power of -73 dBm. This is a level of 50 microvolts at the receiver's antenna input assuming the input impedance of the receiver is 50 ohms "
Also -73dBm is 30dBuV on 50 Ohms. Often receiver sensitivity is in microvolts at 10dB S/N, though in dBuV in the service/alignment manual. Typical uV (not dBm or dBuV) is over 30 at 100 kHz AM, 3 for SSB and as low as 0.1 UHF SSB. FM is usually more sensitive than AM for 10 db S/N and SSB maybe 30x to 50x more sensitive than AM.
I use a 30dB attenuator on the TinySA basic and up to 100 dB on my Rigol tracking generator (fixed 30 dB and a 0 to 70dB that has 10dB steps).
Has your Drake 50 kHz rather than 100 kHZ minimum RF in, or is 50 kHz the IF? Note the aerial connection is 50 Ohms, but connections to the IF should be high impedance or you detune it. Plenty of Drake receivers do have a 50 kHz IF.
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Re: NOISE GENERATOR for the HOME BREWERS
David,
I am aware that you stated Ham Radio.
I've searched their archives as well as their cumulative indexes with no results. There are 269 Ham Radio editions in the index, from Feb 1968 to June 1990.?
I then did a generic search using Ham Radio Magazine as the search topic, which came back with the QST articles.
Richard?
It was in HAM RADIO, not QST.? I noted that in the email.? Try the archives of HAM RADIO magazine.
Dave - W?LEV
On Sat, May 24, 2025 at 12:12?AM Richard Jamsek via <K8cyk56= [email protected]> wrote: Hi Dave,
There are two noise source articles in QST.
January 1977 pp 22 "Gated Noise Source"??
May 1994 pp37 "Calibrated Noise Source"
Is the January 1977 the article you are referring to?
Regards, Richard?
The best ever ham radio publication, Ham Radio, once published a relatively simple project:? a "Gated Noise Source".? I built and extensively used one from MF, HF, VHF, UHF, and through 1296.? Search the Ham Radio archives and you'll locate it.? If you don't want the "gating" function, its even simpler.
HINT:? Low voltage Zeners biassed just as the break into conduction produce the most noise.? You can select them using an o'scope of sufficient BW.? Or, better yet, your TinySA!? Be sure to decouple the bias from the SA.
Dave - W?LEV
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Re: TinySA Ultra 50 Khz as a signal generator
I have been this evening trying with the 209 and the TinySA; same results even with a different voltmeter.
S-meter is deflected, I have tested with different output levels, but voltmeter is always stuck no movement at all.
?
On some receivers, the S Meter will go towards full scale as the RF Gain is turned down and the receiver goes to low sensitivity..
?
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Re: NOISE GENERATOR for the HOME BREWERS
It was in HAM RADIO, not QST.? I noted that in the email.? Try the archives of HAM RADIO magazine.
Dave - W?LEV
On Sat, May 24, 2025 at 12:12?AM Richard Jamsek via <K8cyk56= [email protected]> wrote: Hi Dave,
There are two noise source articles in QST.
January 1977 pp 22 "Gated Noise Source"??
May 1994 pp37 "Calibrated Noise Source"
Is the January 1977 the article you are referring to?
Regards, Richard?
The best ever ham radio publication, Ham Radio, once published a relatively simple project:? a "Gated Noise Source".? I built and extensively used one from MF, HF, VHF, UHF, and through 1296.? Search the Ham Radio archives and you'll locate it.? If you don't want the "gating" function, its even simpler.
HINT:? Low voltage Zeners biassed just as the break into conduction produce the most noise.? You can select them using an o'scope of sufficient BW.? Or, better yet, your TinySA!? Be sure to decouple the bias from the SA.
Dave - W?LEV
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Re: NOISE GENERATOR for the HOME BREWERS
Hi Dave,
There are two noise source articles in QST.
January 1977 pp 22 "Gated Noise Source"??
May 1994 pp37 "Calibrated Noise Source"
Is the January 1977 the article you are referring to?
Regards, Richard?
The best ever ham radio publication, Ham Radio, once published a relatively simple project:? a "Gated Noise Source".? I built and extensively used one from MF, HF, VHF, UHF, and through 1296.? Search the Ham Radio archives and you'll locate it.? If you don't want the "gating" function, its even simpler.
HINT:? Low voltage Zeners biassed just as the break into conduction produce the most noise.? You can select them using an o'scope of sufficient BW.? Or, better yet, your TinySA!? Be sure to decouple the bias from the SA.
Dave - W?LEV
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NOISE GENERATOR for the HOME BREWERS
The best ever ham radio publication, Ham Radio, once published a relatively simple project:? a "Gated Noise Source".? I built and extensively used one from MF, HF, VHF, UHF, and through 1296.? Search the Ham Radio archives and you'll locate it.? If you don't want the "gating" function, its even simpler.
HINT:? Low voltage Zeners biassed just as the break into conduction produce the most noise.? You can select them using an o'scope of sufficient BW.? Or, better yet, your TinySA!? Be sure to decouple the bias from the SA.
Dave - W?LEV
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Re: TinySA Ultra 50 Khz as a signal generator
Yes, but the issue is that whatever the output level is there is no a slight deflection , it remains stuck always in 1,6 volts. I have tried with? all levels that the Tiny gives. Right now? I attach photos with -110? -71 and -23 this happen in the two SPR4's that I have.
?
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Sorry, there will be NO noise generator inside the tinySA
Topic closed
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Designer of the tinySA
For more info go to
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Woul be nice Erik, while everyone can argue that an analog one can be better .
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Re: TinySA Ultra 50 Khz as a signal generator
You do realise that you are looking for the agc voltage to reduce as the signal level increases?? So the procedure is to set the generator level so that you see a slight decrease in the agc voltage on the multi-meter, then zero beat, and then tune the coils for MINIUM agc voltage (ie bigger signal)??? 73 Jeff G8HUL ________________________________________ From: [email protected] < [email protected]> on behalf of enriqueeeeee2001 via groups.io <enriqueeeeee2001@...> Sent: Friday, May 23, 2025 18:47 To: [email protected] < [email protected]> Subject: Re: [tinysa] TinySA Ultra 50 Khz as a signal generator I have been this evening trying with the 209 and the TinySA; same results even with a different voltmeter. S-meter is deflected, I have tested with different output levels, but voltmeter is always stuck no movement at all. I have tweaked the coils. Generatos is working as it should I can heard the tone.? Some photos are attached. Do not know what to do or that is happening.?[X][X][X][X]
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Mike EI9FEB
Ken