TR696FD1 Side Band Drifting ! ! !

[curlyjo]

Hi. Anyone have any solid cures to stop this radio from drifting on Side Band? I got this radio in January and this past week it started drifting even after a ten to fifteen minute warm up. To bad! It was a good skip shooter. Lots a good reports DXing and local rag chew. I would not mind sending It to the right shop that does a good SSB Alignment. What about EPT06960Z Main Board Modifications? I.E. --- Power Amp Improvement (2SB754)-Q54 ; AM AF Amplifier Improvement - Q55; RF Output Increase Modification? As mention in The Defpom EPT06960Z Galaxy 949/959 modifications. Anyone have the same trouble? Should I ditch it and get a RCI 2950?

 

[ExitThirteen]

It's a common problem with those radios. Not much you can do with making them more "drift-free", really. If you want solid, drift-free SSB performance, go with the RCI 2950DX, or if you like running a CB, get yourself something that has the D858 PLL AM/SSB chassis, or the D2824 PLL AM/SSB chassis like the Cobra 146GTL. Those two CB radio chassis will give you great SSB performance. But if you like the 2950DX and you have the coin, snag a 2950.



Just my .02 worth.


~Cheers~

 

[n0zna]

Get a small

frian of wheat blulb and put it on the master osilator xtal,i have done it with also of radios...had a ss360 back in the 80s and it was worse than my siltronixs in the car on Missouri weather,hehe 73 de n0zna

 

[Robb]

Hi. Anyone have any solid cures to stop this radio from drifting on Side Band? I got this radio in January and this past week it started drifting even after a ten to fifteen minute warm up. To bad! It was a good skip shooter. Lots a good reports DXing and local rag chew. I would not mind sending It to the right shop that does a good SSB Alignment. What about EPT06960Z Main Board Modifications? I.E. --- Power Amp Improvement (2SB754)-Q54 ; AM AF Amplifier Improvement - Q55; RF Output Increase Modification? As mention in The Defpom EPT06960Z Galaxy 949/959 modifications. Anyone have the same trouble? Should I ditch it and get a RCI 2950?

These radios are just fine once they reach operating temperature AND their voltage stabilizes. More importantly, if you use them indoors and have a stable room temperature. Then drifting isn't a problem. But if you put them in a car and it is cold outside (even a little bit); they will drift. I had the very same radio you are asking about. Only too familiar with the problem you mentioned. For that reason, I researched this issue and asked a few techs about the cause.

The problem with this radio is in the design of the circuit and the choice of the oscillator coil values. These coils values (in mH's) have values that are too wide. In fact, when trying to align the oscillators, these coils are very touchy. The slightest turn of the coil's tuning slug will change the operating frequency drastically. They (the mfr/designer) should have changed out these coils for a value that is closer/narrower to what is essential; but no engineer bothered to do that. It is not exactly an easy job to do successfully as a hobbyist fixing it either - IMO. When these very sensitive coils are cold, they will change their value and cause a loss in frequency stability. The same drift problem exists for many other Galaxy radios, like the DX-99V and similar chassis. Some Ranger series radios too. Changing out the crystals to a better quality one will only help marginally.

The best cure is preventative; keep the radio in an environment where the temperature doesn't change much. Use it as a base radio. Aligning the radio won't help if there is a great swing in ambient temperature. Either too warm or too cold will get it drifting in two different directions. Other than that, they are excellent radios. I've aligned and modded this radio (with just about all of the mods you listed above) and it is a real performer. Very clean transmit and a nice receive too.

 

[cbradiomagazine.com]

Unlock the clarifier - easy mod. That way you can control where you are transmitting until it warms up.

 

[9C1Driver]

I had one several years ago when Custom cb had them for sale at X-Mas time for under 100 bucks. I was hoping it would perform like an old Cobra 148F, had a receive mod, audio mod, and Viagra board done. In the mobile it would drift as bad a s a Galaxy 88/99. Drove me nuts. Sold it for a loss.

 

[secret squirrel]

Thank you Robb,

I had always wondered people were constantly complaining about when talking about Galaxy SSB drift. I have had a Texas Ranger 696FD1 since back when the refurbs sold for 180.00. It has the clarifier unlocked. If you let it warm up for ten minutes it is stable, but I only use it as a base station. It is mounted to the underside of a shelf in my basement workshop. When I had if in the mobile I used it on AM only. Thanks for the explanation of board design.

 

[curlyjo]

Thank you for all the feed back! I use mine only as a base. Last sat. it got over a 100 in my garage where my station is. It was on for 4 or 5 hours before I started talking on it. That's when I started having issues with my radio. Hope it bounces back after a good cool down. If it does't , what then? I really like this radio.