Much improved tuning resolution, mechnical mod
The FRG7 has around 12 turns of the tuning knob to cover a 1 meg band segment, pretty fast, requiring the finesse of? safe crackers hands to tune in that ssb station, especially when the machine hs been fitted with narrow filters. Here is a very simple mod to slow? that tuning speed to 75 turns band end to end. Remove the central plastic tuning dial from the kilocycle tuning capacitor, held on by one central nut, careful maneuvering? under the S meter will see it free. Remove the three wires from this capacitor, remove the main tuning knob and carefully lift it out.? ?Buy? a ball reduction drive, these can be got almost anywhere, and eye up the space available after removing the front facia plate. Two 2.5 mm holes are drilled into the front chassis to mount the added ball drive in line with the existing tuning shaft. The existing tuning shaft will need shortening, use a hacksaw.? Measure carefully. The radio can now be reassembled. The kilocycle tuning capacitor can now be slid back into the existing cavity another 15mm or so, and new mounting holes drilled to reattach it to the chassis. Reconnect the three wires to the tuning capacitor. The dial drum is now too small. I found a plastic jar lid? the right diameter and drilled through the center to mount it to the shaft. Masking tape around the edge can be used to mark the 100 and 10 kc increments accurately as the radio is tuned, then this is transferred to a drawing program to make? A professional looking dial..... Im still getting round doing that part..... Tuning is now so much easier, and the fine tune is no longer needed.. Originally, the kilocycle tuning is mounted forward toward the front panel as here. .  .... After the mod, it is mounted toward the rear, you can see the added ball drive on the front panel... 
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Re: Newly acquired FRG7 Loop light stuck on/loop not locking
Here is a simple realignment method requiring few test equipments.
https://worldradiohistory.com/UK/Short-Wave-UK/80s/SWM-1981-10.pdf?
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Re: Newly acquired FRG7 Loop light stuck on/loop not locking
Thanks again everyone for the responses.?
I do not own an oscilloscope, been meaning to get one for some time now. I think that is the only way I can get further diagnosing, as I am not used to transistor gear or wadley loop receivers, I have only repaired tube gear and built Regen receivers before, never toyed with something like this. I only own several DMMs, a VTVM and a basic Heathkit analogue RF generator.?
An update on where I am at right now - I removed all the solder off the board besides the blob on L101. The remaining blob was on c117 next to T05 and T06 and was not electrically connected. I am glad that coil L101 is not critical for SW listening. I was not looking forward to winding a coil that small.
The receiver has not worked at all since my initial post. I will better describe the behavior here:
The lock light only goes out when the MHZ dial is tuned to 0, peaking in noise to the right of the 0. The light however will not go out when the band switch is set to the AM band, only on bands 2-4. The preselect still does not seem to have any affect on this. I do get S meter movement when tuned here.?
I will see if anyone local has an oscilloscope I can borrow, or maybe look at getting a used one.?
I will try reflowing the board as suggested, in particular I will focus around the IF cans. I will only use a soldering iron because as Pentagrid pointed out old PCBs are fragile and not up to the task. I plan on working on different parts of the board simultaneously to spread the heat out better.
Any other suggestions before I look for an oscilloscope?
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Re: Newly acquired FRG7 Loop light stuck on/loop not locking
NEVER? get? a hot air gun near these old circuit boards. These boards are very poor quality by modern standards and the tracks will be damaged very easily..
L101 is the low frequency RF tuned circuit, so is not the cause of the problem you describe. This tuned circuit is only used to peak the front end used from 500kcs through to around? 1800kcs.
Ideally, you would connect an oscilloscope to? TP109 and monitor? the waveform. This should rise and fall smoothly as the MCs control is adjusted through its range.
.........
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Re: Newly acquired FRG7 Loop light stuck on/loop not locking
I suspect cracked solder joints based on age and the works sometimes. Clean and flux the board, reflow with a hot air gun and I'll bet it's fixed.
Then yuo can proceed with the alignment process.
Have Fun!
Reg
On Saturday, November 18, 2023 at 06:39:21 AM CST, <dentycamera@...> wrote:
Thank you Pentagrid for your quick reply. I think you might be onto something. The set functions very rarely I've only gotten it 3-4 times out of dozens of tries. I'll talk more in depth now about issues as I didn't want my first post to be too wordy.
I did notice that sometimes when the set was functioning it would almost sound like it was entering regeneration like a Regen set. It would be very slight, but it would start to oscillate very slightly and was very easy to tune out and back on frequency and have it disappear. This only happened once or twice in 6-7 hours of listening. The receiver remained extremely stable throughout the sessions I had it going.
The owner whilst butchering the RF board was not shy with the plumbing solder and made a mess, solder did drip on a couple components. What was easy to clean off (solder blobs stuck to the board for example) I removed. I got all the solder off except on 2 parts. It got onto 1 capacitor, but seems to be electrically isolated. I will probably replace this capacitor, as I feel like this will affect the function and possibly allow signals to enter/leave. The part I am majorly concerned about is L101. The previous owner allowed a solder blob to make it onto one of the windings on the coil. The coil still has good continuity, but the solder also has continuity to the rest of the coil. This coil either needs rewinding or replaced, as sections of that coil are probably bypassed by the solder. I anticipated needing to replace that coil before the set was working at all, but was surprised when it started to work and work well on what seemed like all bands.
Does anyone on here have a source for L101 for the RF board, or any advice on whether this solder blob on L101 would affect the radio in the way I am describing? I am not familiar with the way these sets function. I will most likely try to wind a new L101 or try to find a replacement even if this not the root of my problem, but I would like to avoid buying a whole other FRG7 to save this one, as this one isn't in the best shape as you can imagine.
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Re: Newly acquired FRG7 Loop light stuck on/loop not locking
Thank you Pentagrid for your quick reply. I think you might be onto something. The set functions very rarely I've only gotten it 3-4 times out of dozens of tries. I'll talk more in depth now about issues as I didn't want my first post to be too wordy.
I did notice that sometimes when the set was functioning it would almost sound like it was entering regeneration like a Regen set. It would be very slight, but it would start to oscillate very slightly and was very easy to tune out and back on frequency and have it disappear. This only happened once or twice in 6-7 hours of listening. The receiver remained extremely stable throughout the sessions I had it going.
The owner whilst butchering the RF board was not shy with the plumbing solder and made a mess, solder did drip on a couple components. What was easy to clean off (solder blobs stuck to the board for example) I removed. I got all the solder off except on 2 parts. It got onto 1 capacitor, but seems to be electrically isolated. I will probably replace this capacitor, as I feel like this will affect the function and possibly allow signals to enter/leave. The part I am majorly concerned about is L101. The previous owner allowed a solder blob to make it onto one of the windings on the coil. The coil still has good continuity, but the solder also has continuity to the rest of the coil. This coil either needs rewinding or replaced, as sections of that coil are probably bypassed by the solder. I anticipated needing to replace that coil before the set was working at all, but was surprised when it started to work and work well on what seemed like all bands.
Does anyone on here have a source for L101 for the RF board, or any advice on whether this solder blob on L101 would affect the radio in the way I am describing? I am not familiar with the way these sets function. I will most likely try to wind a new L101 or try to find a replacement even if this not the root of my problem, but I would like to avoid buying a whole other FRG7 to save this one, as this one isn't in the best shape as you can imagine.
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Re: Newly acquired FRG7 Loop light stuck on/loop not locking
My first guess is the loop section is randomly going into oscillation. Is there any sign the previous owner has "adjusted" any of the tuning coils?? Next time the light wont extinguish, carefully try tuning one coil off resonance to see if effects the symptoms. If so, it is reasonably easy to retune these correctly. These coils are in a row on the right? hand side of the RF board.? The first signal IF are the coils on the left. Also check for any damaged components in that area,? especially bypass capacitors. This stage operates at around 55 MHz with very high gain.
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Newly acquired FRG7 Loop light stuck on/loop not locking
Hello Everyone,
I just acquired a broken FRG-7. I bought it untested for a decent price.?
After it arrived I tested it and confirmed my suspicions that the unit was not functioning. It appeared to lock correctly, tuning the MHZ dial the lock light functioned correctly but there was no readout on the S meter, and peaking with the preselect did nothing.
I opened it up and found the previous owner had butchered the RF board, attempting to replace the front end transistor trying to swap it for an NTE 454. An attempt was made to solder the leads of the 454 to the old leads of the old front end transistor, the previous owner trying to use what I assume was plumbing solder. I removed all the butchery and hooked the NTE 454 up correctly.
The receiver started to work immediately, and I was able to tune and peak on all bands. It was on for a few minutes while I tuned around the bands early in the day. I was able to get the BBC and several time signals. Turning the unit off and coming back to it a few hours later the lock light was stuck on, the receiver completely deaf in the front end. The lock light would only turn off when setting the MHZ dial to the lowest frequency.
I read the manual, on this issue and took note of where VR102 was set, ans rotated it around a few times. I also used contact cleaner on all the switches, power switch, band switch, mode and VR102, still nothing. Lock light is stuck on. I turned it off and turned it back on and BOOM! It's working again! I let the unit run for 4 hours listening to all sorts of shortwave programs. Switching After 4 hours I turned the unit off and then immediately back on and the lock light is stuck again.?
Anyone have any idea what could be causing this behavior? The unit once working works flawlessly for hours, but it will then refuse to work at random, requiring random amounts of turning off and on again? I did read the PSU and its outputting high at 15.9 volts. Could the electrolytics in the PSU and AF board be causing power issues causing the receiver not to lock?
Let me know what you think
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Search on eBay: Yaesu FRG-7 kit for digital frequency and S-meter readout
Hello Marcel,
This looks great.
I'm very interested, so please would you be so kind as to post the eBay link or item number so I can see it?
Also, do you ship to the UK?
I did a Worldwide search for "FRG-7 digital readout" but found nothing.
Many thanks.
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Hello Marcel,
This looks great.
I'm very interested, so please would you be so kind as to post the eBay link or item number so I can see it?
Also, do you ship to the UK?
I did a Worldwide search for "FRG-7 digital readout" but found nothing.
Many thanks.
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Pentagrid, thank you for your nice idea. I will have a look at it. That would be a nice upgrade for version 2.0.
I'm also busy making the readout complete wireless, using 2 times the ESP8266 or ESP32. So you don't have to change anything at the FRG, just placing a small PCB and making some connections to the VFO, power supply, mode switch and S-meter.
And you can place your display where ever you like.
But that will be something for the next year.?
Marcel
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Hello Ted, ? Someone else posted the link already. Thank you for that. I’ve checked it on ebay.co.uk and there you can find it. So yes, I do ship it worldwide. UK should not be any problem. ? Marcel ?
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Van: [email protected] < [email protected]> Namens Ted121 via groups.io Verzonden: maandag 13 november 2023 14:52 Aan: [email protected]Onderwerp: Re: [Yaesu-FRG-7] Digital readout ? Hello Marcel,
This looks great.
I'm very interested, so please would you be so kind as to post the eBay link or item number so I can see it?
Also, do you ship to the UK?
I did a Worldwide search for "FRG-7 digital readout" but found nothing.
Many thanks.
|
Hello Marcel,
This looks great.
I'm very interested, so please would you be so kind as to post the eBay link or item number so I can see it?
Also, do you ship to the UK?
I did a Worldwide search for "FRG-7 digital readout" but found nothing.
Many thanks.
|
On 2023-11-13 13:23, Marcel, de PA8MA wrote:
Hello,
A few months ago, I've started to make a digital readout for this
beautiful radio. After a few new versions, it's ready.
Because several people asked me for it, I've made a complete kit,
including mounting hardware and a decent manual (20 pages).
It replaces the S-meter, so no big hardware change. Within 20
minutes, you can bring back the FRG-7 to its original state.
It has adjustable offset for LSB and USB and the AGC
characteristic is included in the software. The digital S-meter is
more accurate now.
If someone is interested, I sell it on ebay.
Marcel
PA8MA
Kit:???
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A very good project Marcel..
Just a suggestion, all the aftermarket add on readouts seem to ignore the megacycle frequency part, when this is very easy to? include.
The Mcs counter only needs a simple prescaler , for example,? ?CMOS HTC7490 divide by 10 connected tp TP101 via a simple buffer amplifier. You already have unused gates in the 7414, that can be used, just? change this to pin compatible? HCT version because of speed This will give? an output frequency of 5.5 mHz to 7 mHz easily counted by the Arduino. Its only the first two digits are required and sent to the left hand display. The second count then takes care of the kHz as you have already done..
So, count up the 5.5 to 7 mHZ prescaler output, subtract the 5.5 mHZ? IF offset, latch and display the two? most significant? digits, then count and display the four kHZ digits, as already done.. By monitoring the "lock"? LED, the Arduino could blank or flash? the mHZ display to indicate mistuning .
?To add this to your existing design would involve only one more IC package, and a slight rework of your PCB, and some extra code.
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Hello, A few months ago, I've started to make a digital readout for this beautiful radio. After a few new versions, it's ready. Because several people asked me for it, I've made a complete kit, including mounting hardware and a decent manual (20 pages). It replaces the S-meter, so no big hardware change. Within 20 minutes, you can bring back the FRG-7 to its original state. It has adjustable offset for LSB and USB and the AGC characteristic is included in the software. The digital S-meter is more accurate now. If someone is interested, I sell it on ebay. Marcel PA8MA .     
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A network of 3D printer owners the print replacement knobs?
Hello all,
As some of you might know, I have designed 3D printable replacement knobs for the FRG-7 switches and have them available through my website () .
I often get request from the US and other countries for these knobs, but international shipping (letter box package up to 100 gram) costs Euro 12,00 (aprx USD 13,00) now a days which I find ridiculous expensive. Especially when a set of 2 knobs cost Euro 1,00.
So because I have made the designs public, everybody who has a 3D printer can print them., I want?to set up a network of 3D printer owners who are willing to do some on-demand print for replacement knobs for help there fellow country frog owners.?
I was wondering what your all think of the above.
--
73 Lex PH2LB?
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Re: FRG-7 Current draw using an external 12V PSU
Well the manual says it draws 14VA at 120vac. So to translate that to 12vdc current draw would be:? So 14va*.7 ( .7 is the typ power factor of a std offline ps) = 9.8W of real power. So I = p/v, 9.8/ 12 = .82A? so your power supply should be fine. I have a frg-7, but never measured the DC current. Of course it will be less if you run it at 13.8V.? Hope this helps.
Bob.?
On Fri, Nov 10, 2023 at 3:44 PM, Hans Ostnell <barentsdx@...> wrote: Hi Guy!
Many thanks!
73's / Hans Hello Hans,
Don't worry, the needed current by the Frog is less than 500 mA. I don't use the internal PS of mine since a long time but an external 13.8 V one and I don't need anymore to put the lighting off to stop this rumble we all know.
Guy on5fm
Le 10 nov. 2023, à 19:50, Hans Ostnell < barentsdx@...> a écrit:
Hi group, and thanks for having me!
Anyone who can tell the current draw for a FRG-7, when using an external 12V PSU? I have a nice linear little PSU, but it's only capable of delivering 0,9 A continously.
Thanks,
Hans / LB6GG
Sandnes, Norway
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Re: FRG-7 Current draw using an external 12V PSU
Hi Guy!
Many thanks!
73's / Hans
Hello Hans,
Don't worry, the needed current by the Frog is less than 500 mA. I don't use the internal PS of mine since a long time but an external 13.8 V one and I don't need anymore to put the lighting off to stop this rumble we all know.
Guy on5fm
Le 10 nov. 2023, à 19:50, Hans Ostnell < barentsdx@...> a écrit:
Hi group, and thanks for having me!
Anyone who can tell the current draw for a FRG-7, when using an external 12V PSU? I have a nice linear little PSU, but it's only capable of delivering 0,9 A continously.
Thanks,
Hans / LB6GG
Sandnes, Norway
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Re: FRG-7 Current draw using an external 12V PSU
Hello Hans,
Don't worry, the needed current by the Frog is less than 500 mA. I don't use the internal PS of mine since a long time but an external 13.8 V one and I don't need anymore to put the lighting off to stop this rumble we all know.
Guy on5fm
Hi group, and thanks for having me!
Anyone who can tell the current draw for a FRG-7, when using an external 12V PSU? I have a nice linear little PSU, but it's only capable of delivering 0,9 A continously.
Thanks,
Hans / LB6GG
Sandnes, Norway
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Arie de Muijnck
Lex PH2LB
Hans Ostnell