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- Yaesu-FRG-7
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Re: New FRG-7 owner
Miguel, Most welcome. Be careful about who you buy a nanoVNA from as there are lots of bad copies. The H4 has the advantage you can load time-frequency FW to it, though not both at the same time. It would be very hard to find a damage level for an internal test point like that. The 1 V at 50 ohms for the signal generator source is as close as you get. I did not insert attenuators. Strictly I should have, but I was only showing the basic setup and forgot. Not good! However, I also know from experience that the output signal is quite low. I just measured the default output of my H4 using a 50 ohm thru and DSO at 7.4 mW or 8.7 dBm. I did not find a way to set the output power on the nanoVNA H4. I also strongly recommend Erik's tinySA. I have several as I use them for signal sources in addition to the SA function, though they need suitable LP filters. FWIW I installed an IEC socket & EMI filter in mine and removed the posts for the factory cable storage setup. Vastly more convenient and it's not so pristine that it mattered. You mention that you are missing some mechanical parts. I have a machine shop so if it's not too complex a part I can probably make one, though shipping cost might be prohibitive. Get it working properly and I think you'll feel the money was well spent. It's an interesting design of considerable fame. Likely you will encounter component drift issues. I had to rework the fine tune capacitance to get it where it should be. The FRG-7 was my first project radio. I also have an FT-101E and TS-520 in queue. A close friend, now SK, carried an FT-101E and FRG-7 on a circumnavigation in a 37' ketch in the '70s. Could not praise the radios highly enough. Four years at sea is a severe test case. Have Fun! Reg W5UHU On Friday, January 17, 2025 at 04:29:04 AM CST, Miguel Frutos via groups.io <m.frutos@...> wrote: Thanks Reg, I will get a NanoVNA as it seems very useful. Just one doubt: where can I see the limits of the signal we can inject in TP103? Don't we need an attenuator in the nano-VNA to protect the radio circuit? - Miguel El vie, 17 ene 2025 a las 2:21, Reginald Beardsley via (<pulaskite=[email protected]>) escribió:
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Re: New FRG-7 owner
Thanks Reg, I will get a NanoVNA as it seems very useful. Just one doubt: where can I see the limits of the signal we can inject in TP103? Don't we need an attenuator in the nano-VNA to protect the radio circuit? - Miguel El vie, 17 ene 2025 a las 2:21, Reginald Beardsley via (<pulaskite=[email protected]>) escribió:
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Re: New FRG-7 owner
Here is my H4 hooked up with CH0 connected to TP103 and TP102 and CH1 connected to TP104 and TP105 per the manual. SMA-M/BNC-F adapters and BNC-M to alligator clips. One can do rather better with a custom cable set at the radio end.
I didn't make any effort to set the nanoVNA properly with a thru cal, etc. It should be done for alignment, but not needed for just a demo. Have Fun! Reg |
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Re: New FRG-7 owner
Miguel, At the time I used my HP 8560A spectrum analyzer which has a tracking generator as the nanoVNA didn't exist yet. The setup is very simple. There are test points at which you inject the signal from the nanoVNA S11 port and test points at which you attach the S21 port to examine the log magnitude display and adjust until the display matches the manual. This is Scalar Network Analysis. Never having done it before, I did it twice. The stages interact a bit and so after I adjusted everything, I went back over it to make sure all the passbands looked correct. I assume you have the factory manual. It's not much, but it's enough. I'll scan it if it's not in the Files section. As you remark you don't have a signal generator I'd like to suggest that you buy a 1 MHz square wave output crystal oscillator module and set it up as a 0 dBm (1 mW) signal source. That will give you markers every 1 MHz. You'll need to add a resistive matching network with 50 ohm output impedance that lowers the signal level. Put it in a neat box and you'll have a very useful piece of test kit. That said, just building it on a breadboard with no connection will work. Just not homebuilt test gear which is the best kind. BTW If you box it, label it. I have a box of such things I built but never labeled. It's a real puzzle to figure out what they are 40 years later. The tinySA is an excellent signal generator if you add a harmonic filter, but you can't use it as an SNA as you can the nanoVNA. In the absence of other indications, I suggest you start at the antenna and look at the signal with a nanoVNA as you work through the circuit section by section. Connect S11 to the antenna and start tracing through the schematic with a probe connected to S21. Make sure twisting the knobs produces the desired result The mode switch has been a continuing annoyance on mine. I need to take it apart and remedy the intermittent contact. Have Fun! Reg On Monday, January 13, 2025 at 04:50:11 AM CST, Miguel Frutos via groups.io <m.frutos@...> wrote: Reginald, I would be interested in learning how to do the alignment?using a nanoVNA, if you are kind enough to share the process. I thought nanoVNA was only for antenna / filter testing; so you use it in place of a signal generator? I don't own one but would consider getting one if it is useful. - Miguel El dom, 12 ene 2025 a las 3:40, Reginald Beardsley via (<pulaskite=[email protected]>) escribió:
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Re: New FRG-7 owner
开云体育Well if the red LED is extinguishing that means at TP110 you have enough signal. But it is a tad complex this radio. May I direct you to articles in Short wave magazine written by JL Linsley Hood. September and October 1981. The first article explains how the radio works and the second one how to align it. You need to do some research to understand the circuitry. And I would advise against tweaking any coil slugs or caps you until you know what you are doing. Connecting a sensitive longer scale voltmeter across the S meter is a good method when aligning the set.?First off check out the power supplies. The mains transformer is centre tapped and full wave rectified. The DC then passes through S5-b, to Q411 via the choke. There is about 17v here. The voltage regulator delivers 10v which generally supplies much of
the circuitry. Just after Q411 is zenor diode D413 which develops the 9v line. ?This is found on the green wires under the audio board. This voltage is the supply to the HG oscillator box that generates the MHz signals and also the 2-3MHz oscillator board
with Q201. The IC Q106 mixes the 2-3MHz signal and the comb of frequencies coming from Q301.?
I will stop here as Lindsley Hood explains it all very clearly.
Mike G4THN
Sent from Mike's iPad.
On 13 Jan 2025, at 10:43, Miguel Frutos via groups.io <m.frutos@...> wrote:
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Re: New FRG-7 owner
Reginald, I would be interested in learning how to do the alignment?using a nanoVNA, if you are kind enough to share the process. I thought nanoVNA was only for antenna / filter testing; so you use it in place of a signal generator? I don't own one but would consider getting one if it is useful. - Miguel El dom, 12 ene 2025 a las 3:40, Reginald Beardsley via (<pulaskite=[email protected]>) escribió:
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Re: New FRG-7 owner
Thanks Mike for the hints which were?very helpful. I followed your procedure without success: the lock light would never go off (sometimes it would just dim a bit). After touching VR102 as per instruction booklet, the light goes off correctly in every frequency?configuration, but still nothing is tuned. I need to keep troubleshooting Regards, Miguel El sáb, 11 ene 2025 a las 0:11, Mike Anthony via (<g4thn=[email protected]>) escribió:
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Re: New FRG-7 owner
Put Deoxit on the switch contacts and align it using a nanoVNA per the factory manual. . It's an easy radio to work on and a really neat design.It deserves its reputation. Have Fun! Reg On Saturday, January 11, 2025 at 08:45:10 PM CST, Chris Campbell via groups.io <481renton@...> wrote: If the radio has been in storage long, take a can of canned air and blow all the dust off all of the tuner caps. That might help you hear something. ? I have an FRG-7 that was in storage for maybe 10 years and when I first turned it on, everything worked but it wouldn't tune anything.? ? Blowing out the dust from the preselector, MHz, and main tuner caps started it receiving. ? Also, exercise all the bandswitches. ? At least that would be a good start, if you haven't done those things already. ? Hope it helps. |
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Re: New FRG-7 owner
If the radio has been in storage long, take a can of canned air and blow all the dust off all of the tuner caps. That might help you hear something.
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I have an FRG-7 that was in storage for maybe 10 years and when I first turned it on, everything worked but it wouldn't tune anything.?
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Blowing out the dust from the preselector, MHz, and main tuner caps started it receiving.
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Also, exercise all the bandswitches.
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At least that would be a good start, if you haven't done those things already.
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Hope it helps. |
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Re: New FRG-7 owner
开云体育The stuff under the electrolytic caps looks like glue that was used to hold them in place before they were soldered. Look at the top of such caps. Any convex shape is bad news, they should be dead flat on top. First connect an antenna!?If it was working before try the following. Select one of the four bands. Say band C 4-11MHz. Rotate the MHz knob to centre 7 under the curser with the red lamp off. Rotate the preselect knob to get maximum response. There are numbers there to assist.
Finally use the main tuning dial to show half way between 100 and 200. The set is now tuned to 7.150MHz. Tuning around this figure during daytime will almost certainly bring up strong amateur stations. To resolve the SSB, switch the mode switch to LSB. You
will need safe crackers fingers for this and the fine tune control helps here.?
To tune an AM broadcast station switch to either AM or AM/ANL. In general the ATT and TONE switches should be in the centre position.
If none of this works you may have a problem!
Best of luck, they are remarkable receivers.
Mike G4THN Sent from Mike's iPad
On 10 Jan 2025, at 19:32, Miguel Frutos via groups.io <m.frutos@...> wrote:
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Re: New FRG-7 owner
I have an FRG-7 in very good condition which I aligned twice. Once to do it and once to be sure ;-) The results were the same. I also have the full docs. If someone hasn't already documented this on youtu.be I'll be happy to help you, though not on youtu.be. It's very simple with a nanoVNA. It's a bit strange of a radio. Have Fun! Reg On Friday, January 10, 2025 at 01:32:02 PM CST, Miguel Frutos via groups.io <m.frutos@...> wrote: Hello, I collected a FRG-7 yesterday. I thought it was in better shape and probably overpaid?for it (EUR100). The overall aesthetic condition can be improved:
I think all this can be improved. When switching on I can't tune anything, although the previous?owner sent me a video of it working fine, so I guess I have not been lucky yet. There is something under the power capacitors, I'm not sure if this is because they are leaking. Also, some pads seem to be missing in the PCBs (not sure if this is a concern or not). I think everything is fixable. I appreciate?any help or hints you can provide. Regards, Miguel |
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New FRG-7 owner
Hello, I collected a FRG-7 yesterday. I thought it was in better shape and probably overpaid?for it (EUR100). The overall aesthetic condition can be improved:
I think all this can be improved. When switching on I can't tune anything, although the previous?owner sent me a video of it working fine, so I guess I have not been lucky yet. There is something under the power capacitors, I'm not sure if this is because they are leaking. Also, some pads seem to be missing in the PCBs (not sure if this is a concern or not). I think everything is fixable. I appreciate?any help or hints you can provide. Regards, Miguel |
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Re: New FRG7 display from Marcel
No problem Pentagrid,I don't see it as criticism. It's the perfectionist in me who wants to get rid of the burdies. To use the light switch is a nice solution. Kind regards, Op di 5 nov. 2024 21:23 schreef Pentagrid via <dayleedwards=[email protected]>:
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Re: New FRG7 display from Marcel
Marcel, my comment was by no means meant as a criticism, it is almost impossible to marry any digital circuitry into a radio without some interaction. The oscillator in the micro is a square wave generator, and will spatter harmonics all through the SW spectrum. I am suprised how few birdies there are. It could be MUCH worse....... I am perfectly happy to switch the Arduino section off when the rare occasion that a birdie will trash the signal I am receiving, a small compromise really. On Wed, Nov 6, 2024, at 1:48 AM, Marcel, de PA8MA wrote:
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Re: New FRG7 display from Marcel
Hi Pentagrid,
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I've noticed the burdies as well, which I don't like at all. I've tried to reduce them by sending only the necessarry data to the display and use some ferrite in the flatcable, but the Arduino itself procudes burdies. I think the only solution would be shielding of the PCB. I gonna try that as well.
I will let you know about my results.
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Kind regards,
Marcel |
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Re: New FRG7 display from Marcel
Sadly, its RAINING here in NZ today, so installed the new display..... If it rained more, I would be even happier.
Having fat fingers meant it was easier for me to remove the front plastic bezel/faceplate to better access the Smeter area from the front..... just the three knobs and 3 screws need be removed.? Be aware of the lock LED wires when moving the panel outwards.
The display? powered on immediately and works very well indeed.;? I did opt to power the display via the lighting circuit, this allows it to be switched off if the interference obscures a wanted signal. This is really the result of the always unhappy marriage with digital and analog circuits, and several birdies will be noticed as you tune the upper bands. These are spurs generated by the processor, and unless radical shielding measures are taken, its something to be tolerated.
This is a great addition to the FRG7.? ?
Thank you Marcel. |
Lex PH2LB
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