Galaxy 88hl warble

[Fdtrucker]

Replace the 1000uf capacitor that goes off of the 8+ volt regulator. Also check and replace the 10.240Mhz crystal. Also, touch up solder joints in the area of the VCO as well. Do this, and it will fix it.

Just replaced the 1000uf cap and touched up the vfo joints.. I left the xtal alone, gonna see if it works, its warming up as I type.. Keeping my fingers and toes crossed

 

[Fdtrucker]

After warm up it only does it on usb but only if I talk loud.. I can live with that I guess AM LSB and rx are fine

 

[RadioGuy772]

Ok see.... it helped. Now that we have some trust, given that the advice was correct...please do the rest.

Now that you replaced the capacitor, and touched up some solder joints around the VCO (yes, VCO,voltage controlled oscillator, not VFO) REPLACE the 10.240Mhz crystal. The advice I gave was meant to be done in completeness. Not to be a stinker, but there are reasons for this. Your problem will go from being there, to where it's at now, which is "mostly gone" to completely gone.

While you're at it, if you want, and have a decent multimeter that reads current in the ma range, we can help you adjust the bias and make a couple simple resistor changes on the transmitter as well so that it doesn't go negative during SSB speech peaks as well. It will clean it up as far as how it sounds on the air.

 

[Fdtrucker]

Ok see.... it helped. Now that we have some trust, given that the advice was correct...please do the rest.

Now that you replaced the capacitor, and touched up some solder joints around the VCO (yes, VCO,voltage controlled oscillator, not VFO) REPLACE the 10.240Mhz crystal. The advice I gave was meant to be done in completeness. Not to be a stinker, but there are reasons for this. Your problem will go from being there, to where it's at now, which is "mostly gone" to completely gone.

While you're at it, if you want, and have a decent multimeter that reads current in the ma range, we can help you adjust the bias and make a couple simple resistor changes on the transmitter as well so that it doesn't go negative during SSB speech peaks as well. It will clean it up as far as how it sounds on the air.

I will do that when I can. The radio is now in the big rig and it worked nicely all day. I did order another parts 88hl, maybe I can resurrect that one for a spare or use it for parts for the other one..I need a radio for the places I deliver to, so all is on on hold. If the other is crap both are gonna go for sale and i'll get another different radio that doesn't F up like these old relics.

 

[RadioGuy772]

Well the good news, is that most of time time it is simple chinese engineering mistakes, or lack of using proper components and quality control...normally it's a combination of all three. I have spoken so many times to the guys down in San Diego, and their response is always the same.... we have used this circuit design for 20 years and we are unaware of the problem. They are even shooting themselves in the foot by that statement....same design for 20 years? They say it to try to make a point, but sound ridiculous in doing so. They only change the design when they absolutely have to when parts go obsolete.

 

[Inquietude]

I've been fighting an 88 that has a "warble" on SSB transmit. Sounds kinda like I need to clear my throat, especially when I repeat the word "one." I've replaced several caps on the tx side and power supply section since they were probably drying out anyway. I tried a different 10.240 crystal as advised above and still have the problem. Tried some other tricks as well. Still has the same garbage even when I reduce the mic gain. Radioguy, I'd like to hear about your resistor changes you mentioned above. And if anyone has any ideas about the warble go for it. Thanks to all in advance. 73.
Inquietude.

 

[wavrider]

Warble on receive, going to find it in the PLL section of the radio.

Good O scope and some time you will probably find a leaky cap causing low voltage to a transistor making it oscillate or look dirty on the scope.

 

[ExitThirteen]

RadioGuy and Wavrider are right on the money. I've had a couple radios come across my bench with these symptoms, and it turned out to be bad solder joints in the PLL/VCO section of the radio. A common problem, especially if the radio is getting bumped up and down the road in a vehicle. Touch up all the solder joints and replace the 10.240 crystal, re-align the PLL section and you should be good.

As far as the TX warble goes, there's 2 transistors that need to be replaced to help resolve that issue. Replace TR51 with a TIP36C, and replace TR50 with a TIP42C and that should fix the TX warble issues on SSB.

Now if only Galaxy would fix the drift issues... *sigh*

~Cheers~

 

[Inquietude]

Someone changed tr-51 and used two thin mica insulators instead of the thick ceramic one. Guess I'll have to order one of those along with the new transistors mentioned above. The power regulator is an 817 and the driver is a 2sa1012. I have an nte37 but will probably get the tip's and put them in.

Also, I've had some success reducing the drift on the Galaxy 949 and the 2547. I'm going to tinker with this 88 and will let you know if I get anywhere with it. Thanks for the help.