Re: Beginning a FRG-7 restoration
Hi Dieter
Also in the files section "4 - FRG-7 Service Notes" there is a lot of useful info. The two magazine articles by Lindsay Hood are highly recommended reading re theory of operation and alignment.
Regards
Steve
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Re: Beginning a FRG-7 restoration
Hi Dieter.
take a look in the files section, you will find the manual, it’s a little challenging to follow without a scope in that range?
I measured my voltages the other week as I’m chasing issues around a heavily modified unit
i don’t have records with me but there is a pdf that gives a realistic table, it has Fluke in the title
br john
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Beginning a FRG-7 restoration
Hello FRG-7 friends
I have purchased a relatively well preserved FRG-7 from a friend. I owned one as a young SWL and used it to learn CW by copying maritime CW broadcasts on HF.
I wonder if there are recommendations for a general restoration strategy. My FRG-7 is working quite well. I note the locking is perhaps a bit difficult to adjust in certain ranges.
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I am aware of the need to check/replace electrolytic capacitors and I have also seen resistors losing their nominal resistance due to ageing effects.?
So, I am keen on any "must-do" restoration actions and also "don't do" ones. I can imagine that some fine-tuning may perhaps be necessary. Perhaps there are also some often encountered faults in these old receivers.
I bought my unit in 1977 if my memory is correct.?
I understand there is perhaps no separate service manual for the FRG-7. I recall seeing a "voltage chart" which may be the first thing to check.
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Thanks in advance for any comments, advice and information.
73
Dieter
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Re: BBC Short Wave Schedule
Glad they're still on the air. Need to fire up my FRG-7 and listen in. I don't use it enough.
On Wed, Feb 26, 2025 at 3:18?PM Julian_Hardstone via <julian= [email protected]> wrote: As an update to my earlier recommendations for listening to BBC World Service transmissions from Wooferton and external relay stations, I see that the Malaysia and Madagascar tx are no longer used. Vatican City and Oman have been added as relays.
The current schedule can be seen at , and follow the links for more details. This page is updated seasonally.
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?- Julian
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As an update to my earlier recommendations for listening to BBC World Service transmissions from Wooferton and external relay stations, I see that the Malaysia and Madagascar tx are no longer used. Vatican City and Oman have been added as relays.
The current schedule can be seen at , and follow the links for more details. This page is updated seasonally.
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?- Julian
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Re: FRG-7 Mechanical adjustment
So sorry to read your cynical view of SW Broadcast listening Mark; in my experience, as long as you can get a reasonably quiet receive on a long wire or a loop, you will find delights throughout the band. An FRG-7 is a pleasure to drive, and the ability to step in 1MHz increments is good for Broadcast listening.
Before you go out for your daily exercise or shopping round, check the Broadcast bands from 30m up. On 22m you will identify RNZ on a good day. Turkey is everywhere, though English broadcasts are in the afternoon and evening, while China dominates SW 24 hours of the day in all languages. Remember that CRI can be surprisingly strong in the UK, thanks to relays from Wooferton and Germany. In the evening the 'Equatorial' bands are far from equatorial these days, once again CRI is everywhere, and India, the far East, and Dutch pirates. 75m always interests me, if you're lucky you may hear BBC WS from the Singapore relay. Others I like to look for in the morning are BBC French for Africa from Ascension and Madagascar.
Switch to USB and another world opens up, with Volmet stations around the British Isles. Trawlers are everywhere, they don't seem to bother with 'bands' these days.
If you aren't getting anything interesting on your home, just try one of the many Kiwi online SDR systems, some of which have good reception from VLF upwards. I've just spent an hour transfixed while listening to a good one I use. Go to https://rx-tx.info/map-sdr-points , select KiwiSDR and zoom in on your location. When you select one, the operating instructions are linked from the Welcome panel. It may give you a standard you can strive for!
?- Julian
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Re: FRG-7 Mechanical adjustment
If there was anything of interest to take in?I’d agree, alas there is just propaganda and fake American accents … This is doubtful to enrich your grey matter..
Best 73 Radio (a sad demise but it had to come)
On Sunday, February 23, 2025, 6:45 pm, John Walker via groups.io <reeferjon@...> wrote: I actually agree with everything you said and very strongly agree that movement/Gym/walking is priority but what I'm doing here is to also exercise my mind and keep the fundamentals of diagnostics/understanding and process active too.
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Re: FRG-7 Mechanical adjustment
I actually agree with everything you said and very strongly agree that movement/Gym/walking is priority but what I'm doing here is to also exercise my mind and keep the fundamentals of diagnostics/understanding and process active too.
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Re: FRG-7 Mechanical adjustment
You will soon get fed up with it… I’m licenced and I’m Afraid you are now better off going to a gym or exercising of some type to keep healthy.. Sitting around a radio in 2025 is the most unhealthy pastime there is gents.. Most of the broadcast stations are gone on the tropical bands too. All I hear now is old hams talking to old hams about their prostate operations on 75 metres.. The Golden age is now over.. Spend your time getting fit, it’s wiser..
73 M
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On 23 Feb 2025, at 16:39, John Walker via groups.io <reeferjon@...> wrote:
? I'm quite lucky up here on north west UK, there are still some broadcast stations to listen to and the odd Ham as well, however, I'm enjoying the experience and 're-learning' a lot as well.
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Br.
John.
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Re: FRG-7 Mechanical adjustment
I'm quite lucky up here on north west UK, there are still some broadcast stations to listen to and the odd Ham as well, however, I'm enjoying the experience and 're-learning' a lot as well.
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Br.
John.
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Re: FRG-7 Mechanical adjustment
But John? There is nothing left to listen to anymore
On Sunday, February 23, 2025, 4:01 pm, John Walker via groups.io <reeferjon@...> wrote: Got it, there is a flat tension plate behind the front panel, remove the panel, clamp the shaft and you can increase the drag on the clutch.
Cleaned all the muck out and ts much better now.
Looks like its been dropped on its face at some time as shafts are a little bend.
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Anyone any thoughts on how to get rid of decade of nicotine smell?
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Br John.?
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Re: FRG-7 Mechanical adjustment
Got it, there is a flat tension plate behind the front panel, remove the panel, clamp the shaft and you can increase the drag on the clutch.
Cleaned all the muck out and ts much better now.
Looks like its been dropped on its face at some time as shafts are a little bend.
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Anyone any thoughts on how to get rid of decade of nicotine smell?
?
Br John.?
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FRG-7 Mechanical adjustment
Good day all.
Question, how does the preselect drive clutch work please, has anyone had to adjust it.
I have some backlash that seems to be within the clutch mechanism, the output shaft to the toothed drive for drum and on to the VC couplers is good.
Interested if anyone has stripped the clutch before.
Br.
John.
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Started again from the beginning.
1. stripped out the 2m converter, completely rewired the antenna connections and removed a pair of 1meg resisters from So239.
2. stripped the Band switch and cleaned the wipers, this made a big difference
3. cleaned the Dx/LOCAL switch again
4. mechanically aligned the preselect/Mhz and Khz dials
5. cleaned up potential dry joints
6. washed off the PCBs with IPA and inspected tracks
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Results, much better but still issues.
Worked part way through the alignment, stopped due to scope not being up to parr.
Worked through Q101 to Q111 voltage chart, found Q110 and Q111 C&B voltages out to list, adjusted VR102 nearly 1/4 turn and they are now somewhere near, LED goes out on most of range now, but its clear there is still a problem in the selective filter area.
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Good day All.
I have a TinySA that have been using as an RF sig gen and a Zeewiie DSO1151g scope that 'should' run past 100Mhz, well lets just say 30Mhz is about its limit, this means I'm unable to look at signals in RF range.
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My question, attached are sample alignment procedures.
Given that I dont have a fit-for-purpose scope (have three scope probes) but do have a TinySA and a NanoVNA (on the way) how should I then perform the alignements that require use of a scope, so what modifications do I make to testing and how should I review the results.
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Scopes, Im happy with using. SA and VNA interpretation, I'm not familiar with and no option to buy a higher bandwidth scope.
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Thank you.
Br John.
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Hey Mike.
Changed it today, nothing wrong with it, took the opportunity to resolder the joints around the area, no difference.
Will retake measurements of all TP again tomorrow and may crank up the signal gen a few db
Br
John
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On 9 Feb 2025, at 21:35, Mike Anthony via groups.io <g4thn@...> wrote:
? Indeed, I get 112mV as well at the junction of R117 & R118. ?So something is shorted to ground here. R118 perhaps?
Sent from Mike's iPad
On 9 Feb 2025, at 15:10, reeferjon via groups.io <reeferjon@...> wrote:
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[Edited Message Follows]
Thank you Mike.
I do have the afore mentioned pages and they are great IF the set is working :-)
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I did some more investigation around Q106, all of the supplies measure correct.
No o/p on pin3 which is TP107
No i/p on Pin11
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TP101 confirms as 58Mhz
Then we come to a PD made up of R117 and R118, I'm not getting anything 'measurable' after R117, what level would that lightly be.
I calc that if i/p is 350mV then o/p should be around 112mV.
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I know the tracks are a bit fragile on these so will await a response before unsoldering on end and checking the values of R117 and R118.
<Screenshot 2025-02-09 143051.jpg>
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Indeed, I get 112mV as well at the junction of R117 & R118. ?So something is shorted to ground here. R118 perhaps?
Sent from Mike's iPad
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On 9 Feb 2025, at 15:10, reeferjon via groups.io <reeferjon@...> wrote:
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[Edited Message Follows]
Thank you Mike.
I do have the afore mentioned pages and they are great IF the set is working :-)
?
I did some more investigation around Q106, all of the supplies measure correct.
No o/p on pin3 which is TP107
No i/p on Pin11
?
TP101 confirms as 58Mhz
Then we come to a PD made up of R117 and R118, I'm not getting anything 'measurable' after R117, what level would that lightly be.
I calc that if i/p is 350mV then o/p should be around 112mV.
?
I know the tracks are a bit fragile on these so will await a response before unsoldering on end and checking the values of R117 and R118.
<Screenshot 2025-02-09 143051.jpg>
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Thank you Mike.
I do have the afore mentioned pages and they are great IF the set is working :-)
?
I did some more investigation around Q106, all of the supplies measure correct.
No o/p on pin3 which is TP107
No i/p on Pin11
?
TP101 confirms as 58Mhz
Then we come to a PD made up of R117 and R118, I'm not getting anything 'measurable' after R117, what level would that lightly be.
I calc that if i/p is 350mV then o/p should be around 112mV.
?
I know the tracks are a bit fragile on these so will await a response before unsoldering on end and checking the values of R117 and R118.
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See comments below line by line. I have to ask first though, do you have circuit diagram? Better still the September and October 1981 articles in Short Wave magazine by JL Linsley Hood? With these
to hand and read and understood you will be in a much better place to get the Frog working again.
?
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From: [email protected] <[email protected]>
On Behalf Of reeferjon via groups.io
Sent: 08 February 2025 18:52
To: [email protected]
Subject: Re: [Yaesu-FRG-7] Ebay Lucky-Dip FRG7
?
Today spent a few hours to see why its deaf and the lock led stays on below approx 15Mhz.
These are the measurements I got so far.
Inject 3Mhz into antenna
Mhz set to 3Mhz, preselect set to 3Mhz
Band set to B
Am set to AM
ATT and tone set to normal
Dial set to 0Khz
S meter reads 9-11
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Lock LED is lit, will not go out (goes out above 15Mhz). The LED is driven by the Darlington pair Q110 and Q111. When there is enough voltage (>0.5rms) present at TP110 then this is enough to extinguish the LED. Therefore, you are not getting
enough signal down the Q107 to Q109 amplifier chain. Q111 will be on and the LED lit with its base drive supplied by R131. But when Q110 gets enough base drive to turn on, it will remove the base voltage from Q111 and the LED will go out.
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TP101 = 58Mhz approx 350mV pk-pk This shows that the Q201 oscillator stage is functioning correctly.
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TP103 = 0hz ?approx 0mV pkpk Here is certainly one problem. If you are injecting a 3MHz signal into the antenna socket then you should be able to see this at TP103. So the signal is getting lost somewhere between the antenna socket and
TP103. Check at the input to T102 and then at C101 which is the input to RF amp Q101. After this there is the LPF which is that rod with several coils.
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TP104 = 2.5Mhz approx 100mV pkpk This is at the output of the second mixer Q105. For a signal to appear here this is likely coming from the signal you see at TP101 which gets fed two ways, one of which ends at the first mixer which is Q102
and Q103. Try looking for this at VR101. After this the signal will progress through T105 T106, Q104, T107 and T108 then Q105 before appearing at TP105.
TP106 = 1Mhz approx 800mV pkpk This is the output signal from the sealed box under the chassis from the crystal oscillator Q301. So this is working
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TP107 = 0Mhz approx 0mV This suggests that Q106 which is the IC on the board, has died. This chip mixes the 58MHz and 2-3MHz signals and so if this is dead, there will be no signal at TP107 ( and neither will there be enough signal at TP110
to turn off the LED)
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TP109 = 0Mhz approx 0mV This reinforces my guess that Q106 is dead since this test point is on the end of the chain starting at Q106. You should be seeing the output of the Q106, Q107, Q108 and Q109 chain here.
TP110 = 52Mhz
(TP104 with Mhz and band set to 28Mhz = 52Mhz 200mV pkpk)
I am puzzled about this result. If there is no signal at TP109 then there will be none at TP110 either.
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As to there being no sound output try touching or injecting say 3KHz at the centre connection of the AF gain control. That at least will prove the AF PA stage and associated components.
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Today spent a few hours to see why its deaf and the lock led stays on below approx 15Mhz.
These are the measurements I got so far.
Anyone any thoughts?
?
Inject 3Mhz into antenna
Mhz set to 3Mhz, preselect set to 3Mhz
Band set to B
Am set to AM
ATT and tine set to normal
Dial set to 0Khz
S meter reads 9-11
Lock LED is lit, will not go out (goes out above 15Mhz)
TP101 = 58Mhz approx 350mV pk-pk
TP103 = 0hz ?approx 0mV pkpk
TP104 = 2.5Mhz approx 100mV pkpk
TP106 = 1Mhz approx 800mV pkpk
TP107 = 0Mhz approx 0mV
TP109 = 0Mhz approx 0mV
TP110 = 52Mhz
(TP104 with Mhz and band set to 28Mhz = 52Mhz 200mV pkpk)
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Dieter VK3FFB
Julian_Hardstone
