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In the repair industry, these "events" happen with no explanation, and are the worst thing. Do we give the radio back to the customer knowing full well it is not really repaired, but could fail again at any moment. On the other hand, how can we now repair it properly when it is working fine with no fault to hunt down. A conundrum.
I suggest thanking your lucky stars and enjoy the radio.

Well here's a crazy turn of events.... I removed the cover on the HG unit. poked around a bit. Then removed the enclosure, looked things over and was about to to check the transistor as you suggested.
I powered the rig up and low and behold it's receiving!!! The lock light is going on and off like it should as I tune the MHZ control.
So I guess my question is: Is there a possibility that the crystal was "stuck" as the radio has been sitting for probably a few decades???
I think I'll still replace the crystal but wow... did not expect that... unless something else is lurking !!!
?

The waveform you see at TP019 is the straight through leakage of the first VFO, this is normal, but not seeing anything as you tune up in frequency on the megacycle knob strongly suggests your HG is not working.
Because the lock light does come? on , and off , that suggests the selective amplifier is working fine.
The other TP monitors the second VFO, thats the kilocycle tuning, and given your measurements, is working fine. That section is seperate from the section you are dealing with, so at this stage can be ignored.
At this point, I would put my money on the? HG crystal, these can be found cheaply online.
Otherwise, measure the HG transistor voltages. These vary a little, but there should be around 9 volts on the collector, around 1 volt on the Base, and a few millivolts on the emitter for the transistor to oscillate. If these voltages are in the ballpark, the next step is to replace that crystal.
Replacing that crystal should see the old thing running again. Thats when you can realign the second VFO to conform to the drum markings.

I believe I have the main dial set properly now.
Putting the scope on TP019 I get no waveform unless I move the MHZ dial down to the zero mark (where the led goes out) then I get the waveform below. It does not change when moving the second VFO.?

But when I put the scope on TP401 I do get a waveform that changes in frequency from 3.35 mhz to 2.42 mhz when I tune the second vfo from 0 to 1000. ? ? I hope all this is making some sense and helping!!!




Also checked to make sure that VR102 is not full on. It's at it's aprox. mid point.

I believe the HG is dead. I did as you suggested with a SW SDR and I do not detect any signal at all tuning up and down, and putting the scope on TP106? the output from the HG shows nothing. It is getting the 9V supply
Is there a process to check the crystal?

I really appreciate your help with this..

The HG should provide a very strong fundamental tone at 1 mHz,? especially when the box is removed from the chassis and powered. . Its not uncommon for the crystal to fail. The HG output is at a very low level, a spectrum analyser? is handy here. But, any SW radio placed near will find the harmonics from 1 to 35 megs as you tune up and down the spectrum... use SSB if you have it. thats where those small Chinese radios are handy for this. There is little to check in there really. The two diodes clip the oscillator output giving the distortion to create the harmonics, I guess these could fail, but doubtful.

Your other questions.....
The slight? resistance you feel at the tuning edges is normal, and is to do with the mechanism limiting the end stops.
By loosening the tuning drum center nut,? it can be easily adjusted to agree with the kilocycle markings if the basic arrangement is ok.?

I don't think the HG unit is running. Putting the scope on TP106 I get nothing. It's getting the 9 volts.
I haven't as yet? popped the lid off the HG enclosure.

Yes, you need to fix those? mechanical issues first. It seems someone has really fiddled with this one
The kilocycle tuning capacitor needs careful setting up. With the vanes fully closed, the tuning shaft should be against the stop, and the tuning? indicator? should be aligned with the small triangle mark on the right hand side of the tuning drum.. The tuning cap is not used over its full travel, this is done to give a more linear readout on the scale.? It is normal for the tuning cap to not fully open, so perhaps this has not been changed.? This is a pain to get right, and you will need some very small allen keys to loosen the grubscrews if repairs are needed..
For completeness, the second VFO ,or kilocycle oscillator should be checked, it will run from 2.455 megs to 3.455 to give the 1 meg tuning increments.... and remember it actually tunes backwards.
Connecting your scope to TP109 should reveal a rising and falling waveform amplitude as the Megacycle knob is varied, but the scope will need to be a good one, this section is at 50 odd megs.
If you dont see any waveform here , the fault is either the amplifier chain or the harmonic generator. Sometimes the mixer chip will take a hit, but seldom.
Also check VR102 hasnt been wound fully on. This preset alters the bias on the LED lock lamp, It should go off at one extreme. This section rectifies part of the selective amplifier output signal to indicate correct tuning.

Screen grab of output from osc board. Freq varies smooth from 83 mhz @ 29 mhz down to 54 @ at 0 mhz
taken at TP 101 /102 gnd.

Pentagrid, thanks for the reply.

I did the tests as you described and I could not get any signal on the AM radio tuned to 1mHz positioned near the mixer chip.
But I did get a signal at 84mHz when the mHz knob was set at the 29 mHz position.

Test gear, I do have an oscope, a vintage HeathKit signal generator (restored and works well), a cheap signal tracer, and Multi-meters.

Also another issue I should mention with this radio is that the 1Mhz tuning dial does not move properly. Rotating the large tuning knob to the left the drum display stops at the 200 mark.
When rotating to the right it goes past the 1000 mark to just beyond the small triangle. In observing the related tuning capacitor I do notice the capacitor plates do not fully open nor fully mesh at the ends of travel.
Also i feel a slight resistance in the knob when approaching both ends of travel. I read in another post that lubrication may be the problem but that did not seems to help unless the lube was not applied in the right place.
Do you feel this issue should be addressed prior to the lock light issue??

Brian

The above should have the FM radio tuned to 84 mHz, my mistake.? Most modern digital RXs will tune this low.
To test the selective amplifier you will need? some test gear, do you have any?

The only section you need look at is the 52.5 Mhz selective amplifier as mentioned in that article. Unfortunately, that article refers to a receiver that is already functional, yours is not. Therefore, any alignement suggestions cannot work in your case.
You need to fault find.
The selective amplifier mixes the VHF oscillator, this is the Megahz knob, and the output of the harmonic generator.
Check both these sections .?
If you have little to no test gear, do the following.
To test for harmonic activity in the HG, place a normal AM radio near the first mixer chip, located on the front right of the left? hand PCB. A blank carrier should be heard on the AM radio at 1 mHz.
With an FM radio tuned to 88 MhZ,, the FRG7 megacycle oscillator should be heard on the FM radio when tuned to 29 mHz.
If you hear these, then the fault lies either in the mixer or following amplifier

Greetings, I was given a FRG-7 by a friend. No clue as to the history of this radio. After cleaning all the rotary switches and volume pot I was only able to receive some local AM broadcast as the zero blob on the MHZ dial is the only spot on the MHZ dial where the lock light would go out. Tuning up through the entire MHZ range the lock stays on.
?In reading many posts here it was mentioned to slightly tweak VR102 to get the lock to work properly but no joy.
So I'm at the point of deciding to try a quick alignment as described in the link below or hopefully someone here can suggest other items to check.


Thanks in advance
Brian / N6RZR

Yes. Look at /g/Yaesu-FRG-7/files/2%20-%20Forum%20Rules%20Folder/Yaesu%20FRG-7%20Rules,%20For%20Sale%20or%20Want%20to%20buy%20Posts.txt for selling rules.
73 Roger VE7LB group owner

Are FRG-7 for sale ads permitted ?

Hello,

For someone who is interested. I've posted a short video on Youtube with the right alignement procedure for the LSB and USB offset.


Have fun and enjoy the FROG 7.

Marcel

And if you would like to see the digital readout in action, here is a Youtube link:

73, Marcel de PA8MA

Just a short update about the Ebay link.
The previous link has disappeared because I ran out of stock.
This is the new one for someone who is interested



Regards, Marcel

A quick pic of the few mods I have done to this radio, two diode switched filters, these are? selected via the existing mode switch, SSB/CW? and AM /ANL positions select the narrow, and wide respectively.
As I have previously mentioned, the existing BFO is NOT adequate to service a narrow filter, its long term instability will eventually move it out of the passband, ceramic resonators will do the job, and can be "pulled" to sit on the filter skirts properly.
Other mods done include AGC fast/slow, AGC also applied to the first IF amplifier, and others that escape me at the moment.
But, everyone loves pictures........

Here is the plastic lid I used, almost any lid will do, but make sure the wife is away when choosing. I thort bright pink was rather fetching.