Dymar Two Tone Tester

[ChristianFletcher]

I posted a thread earlier today looking for a manual on a Dymar two tone tester I have on the bench. Well I have done all obvious stuff such as changing some very poorly electrolytic capacitors I have it working to a fashion. I don’t think I am going to turn up a manual or Any service data but thought it worth asking here if anyone has memory of operating one of these or doing two tone SSB testing.

It produces two tones A and B. Now the (A) tone has control to change frequency ranges in three multipliers x10 x100 and x1000. So it’s frequency is adjustable between 3 and 30khz.


But tone (B) just had a selector switch labelled A.B.C.D.E.F.G. But it only appears to have a very small adjust range from 72 to 125hz.

Now I was expecting to be able to adjust (B) tone much higher than that. Actually I expected it to have the same range as (tone A). I expectEd to set frequency of say 3700 and 600hz for example

Can anyone tell me if this is normal etc. The outputs from A and B look like I would expect nice low distortion sine waves with level control. Just odd frequency ranges for tone B ?

Thanks for any help or advice. I’m happy to post a short video etc if that helps explain my question.

Thanks regards Chris

[Station X]

If that's a Dymar 745 the manual gets a mention here:-

https://www.vintage-radio.net/forum/...d.php?t=142555

[ChristianFletcher]

Unfortunately I think Dickie got rid of all the manual years ago.

Chris

[ChristianFletcher]

I think the the signal generator is working as it was designed to work but I would have thought that the 100hz B tone is outside the adio pass band of a typical SSB transmitter. I would be interrested to see any comments regards SSB two tone alignmnet.

Thanks Chris

Link to video below it may just jog a memory etc

https://www.youtube.com/watch?v=5_e7jHbTO40

[ChristianFletcher]

I think the mystery is solved looks like the two tone generator was for providing Continuous Tone coded Squelch. The selection of frequencies for the B tone look very close to ideal. Thanks to George for the information.

[RobGT390]

I have a Dymar but its very different looking compared to yours. It does 3 to 30 on both channel A and B. I use it for setting modulation on ssb transmitters. If you are looking for something similar there are 2 options I found before I got the dymar. Kanga products and spectrum communications do kits to build your own. I came across the kanga one first and built it but it did not work properly, I am sure it must have been something I did incorrectly and kanga where quite helpful trying to diagnose what was going on, but before we got to the bottom of it the dymar came up for sale and I bought it. The kanga did not produce a good sine wave on one channel. It was a little tricky to build too as it has a lot of surface mount components, next time I think I would go with the one from Tony at spectrum communications, but the dymar is working great for me at the moment

[ChristianFletcher]

Thanks Rob

As it turns out my Equipment was a CTCSS generator. Yes I believe that the Kanga product two tone generator is very good. But I built my own in the end. It appears to work OK if not a bit crude. Link below if you want to see it etc

https://youtu.be/OkXAh_wr8VA

Thanks Regards Chris