500V will be enough. Original one is 50V which is easily exceeded when transmitting.
Replacing C116 is critical.
Replacing C116 is critical.
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president HR2510 high swr spikes
- Thread starter tyler sherwood
- Start date
alright went through and ordered the capacitors to change out c112 c114 c115 c116 and c121 will be a little while before i get them
Hmm...IDK - I can see you're not as experienced...
IF you can remove the caps - as necessary, without having to remove the toroid's - then by all means do so - save the headaches of poor alignments if the toroid's don't get positioned back in place correctly - you can ruin the work and not be able to check SWR because these Toroid's are located in aspect BEFORE the RF arrives to the SWR Riser card.
The capacitors - the 560pF usually are disc and can withstand at least 50VDC but most have a minimum of 100V rating so look at the package size, if they are the same in dimension, they usually have the same rated capacity. Same size, same dimensions? Similar in rating 90% of the time.
C116 - As Mike has already suggested, it's a critical value - it's the "last thing" Reflected power sees before the DC shunt wind, and the "First thing" the RF power going out to the antenna sees when transmitting.
This area is where the "Miller Effect" of a Bipolar transistor occurs, this chain of inductive and capacitive parts affects power across the Emitter and Collector of the MRF477 - develop their cyclic currents in this area - it does get warm, and hot in some cases - so as you transmit - heat is the effects of POOR tuning and mismatch power transfer. IF the MRF477 gets hot, this area gets warm too - it is designed to pass a specific range of frequencies - the heat is from the losses of the out of band frequencies the parts are trying to deal with (dissipate).
So if you're not able or ready...don't do this -
The toroid's are made of a rather delicate ceramic material containing Ferric oxide. Nothing too hazardous, but they are like fine dish plates, can be broken if forcibly removed...
So, if your comfortable - you can start by unsoldering the toroid from the foil traces...
Not everyone has access to a heat gun, nor have one available; but a hair dryer or small butane torch can work.
So keep them from shifting and remove the caps, replace with correct values and then carefully replace the toroid's into their positions on the board. A simple dab of epoxy can set them back in position easily enough.
IF you can remove the caps - as necessary, without having to remove the toroid's - then by all means do so - save the headaches of poor alignments if the toroid's don't get positioned back in place correctly - you can ruin the work and not be able to check SWR because these Toroid's are located in aspect BEFORE the RF arrives to the SWR Riser card.
- It is why I mentioned earlier for you to check the SO-239, if it's loose or you have broken soldering joints at the SWR Riser card, they will show SWR issues, the MRF477's power output development is BEFORE RF arrives to the SWR card, so the bad winds or poor soldering - does not always show up at the SWR on the meter - the mistuned section is BEFORE RF arrives in Forward - and Well AFTER in Reflected - you may not see poor tuning from the Final and Driver only by poor RF performance from the poor coupling that can occur if the toroid's are NOT positioned EXACTLY back in place.
- IF the SWR riser card is damaged, or has broken traces feeding to it, they can do far more damage than a bad cap or poorly wound toroid. It will blow the final from poor mismatch (open lines or wrong ones shorted) The SWR card - if broken - will not be able to send out RF to the antenna and not be able to receive well. IF you have poor receive, this SWR Card and parts arriving to the antenna from that point NEEDS to be CHECKED and repaired - repositioned or resolder the joints if they came loose.
The capacitors - the 560pF usually are disc and can withstand at least 50VDC but most have a minimum of 100V rating so look at the package size, if they are the same in dimension, they usually have the same rated capacity. Same size, same dimensions? Similar in rating 90% of the time.
C116 - As Mike has already suggested, it's a critical value - it's the "last thing" Reflected power sees before the DC shunt wind, and the "First thing" the RF power going out to the antenna sees when transmitting.
This area is where the "Miller Effect" of a Bipolar transistor occurs, this chain of inductive and capacitive parts affects power across the Emitter and Collector of the MRF477 - develop their cyclic currents in this area - it does get warm, and hot in some cases - so as you transmit - heat is the effects of POOR tuning and mismatch power transfer. IF the MRF477 gets hot, this area gets warm too - it is designed to pass a specific range of frequencies - the heat is from the losses of the out of band frequencies the parts are trying to deal with (dissipate).
So if you're not able or ready...don't do this -
The toroid's are made of a rather delicate ceramic material containing Ferric oxide. Nothing too hazardous, but they are like fine dish plates, can be broken if forcibly removed...
So, if your comfortable - you can start by unsoldering the toroid from the foil traces...
Not everyone has access to a heat gun, nor have one available; but a hair dryer or small butane torch can work.
- - you can gently, and from some distance from the board (if you use butane) soften the glue bonding using the heat to loosen and remove - carefully and GENTLY - the glue bond holding the toroid to board to remove the ceramic without breaking it.
So keep them from shifting and remove the caps, replace with correct values and then carefully replace the toroid's into their positions on the board. A simple dab of epoxy can set them back in position easily enough.
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yeah i looked at the so 239 doesn't seem to be loose and the solder looks ok and there is actually not a lot of glue holding those toroids on at least compared to some of the other radios that i have seen on youtube the glue really isn't around the capacitors mentioned which is why i was going to change those first instead of jumping directly into messing with those toroids.
actually i just rechecked it for good measure and the inside part of the connector is loose and does make a difference when i wiggle the connector around tried to resolder the wire coming off of it to make sure that wasn't it but that dident make a difference any idea where i can get one online?
nvm i actually had one that's the same as what came off in way better condition. took the heatsink off by unscrewing the final and driver then unsoldered the grounding tabs then installed the new one waiting on the thermal paste for the final and driver before i put it back together. now just so i get it right i do not need the mica insulator on the final correct? i did resolder the 560 disk caps back to the center leg of the final
is there a specific size wire to use from the center inductor to the board the wire that came off isn't really much good and all i have on hand is 24 awg it looks really close to the same stuff that came out of it.
You posted several times since I last reviewed, so I'll try to sum this up in simple fashion - Look Carefully...
Ok, the SO-239 for what it is, is the most abused part of any connection to the radio - it takes the antennas signal brings it into the radio, and takes the radios signal and pipes it to the antenna thru that simple connector out to the antenna thru the coax.
This area is the most prone to losses in signal degradation and performance due to noise - from poor or dirty loose connections that cause so many problems for many operators.
The above...note this is the FOIL side of the HR2510 - back panel - by multi-function connector / jumper and the SO-239 itself.
Please note:
The Schematic shows 5 connections.
Excuse the dirt and dust...
But you have TWO ground connections.
Ok, do you see it?
IF you encounter SWR problems but can't seem to locate them, check your RISER card for SWR - you may have a GROUND LOOP that opened up. I can't stress this enough - but I've seen perfectly good HR2510's go into the trash heap because someone didn't bother to check the GROUND LOOP at the SWR card when they encountered problems they couldn't fix.
Ok, you asked about "gauge" or AWG - I've seen SOLID #14 from a Firestik antenna coil wind soldered there at the antenna "jumper" location - don't fret over it, use something with enough thickness "# AWG wire" to handle the RF, don't skimp on gauge, - Solid works better, but is more brittle - prone to breakage. Stranded is more inductive - so believe me - short jumpers are better than longer snake-ier ones that fold curl or otherwise "dip" back towards the board...
The SO-239 uses the Coax Center Pin.
So if the "Socket" of the SO-239 gets a pin from coax that's too large in diameter, the next coax you use back there to screw in, its' pin may not make a good enough connection to the SO-239 and RF can't get out.
Rear nut? You can use a wrench - two is needed - one to "hold the thread" while the other turns the nut to press fit the connector to the rear panel. The smaller wrench uses the threaded flat to hold and the other tightens or loosens - depending on your replacing or installing.
Hope this helps!
.
Ok, the SO-239 for what it is, is the most abused part of any connection to the radio - it takes the antennas signal brings it into the radio, and takes the radios signal and pipes it to the antenna thru that simple connector out to the antenna thru the coax.
This area is the most prone to losses in signal degradation and performance due to noise - from poor or dirty loose connections that cause so many problems for many operators.
The above...note this is the FOIL side of the HR2510 - back panel - by multi-function connector / jumper and the SO-239 itself.
Please note:
- Heat sink is Aluminum - Anodized and painted.
- Side panels are Steel plated with Galvanized Zinc - prevents rust.
- Uses "screws" and pre-threaded holes to bolt the two together - as one unit to drain off excess heat, provides shielding and protect the innards.
The Schematic shows 5 connections.
- - pass thru (for 2)
- Forward Power Measurement (1)
- Reflected Power Measurement (1)
- Ground (1)
- But you have 6 connections - note this...
Excuse the dirt and dust...
But you have TWO ground connections.
Ok, do you see it?
IF you encounter SWR problems but can't seem to locate them, check your RISER card for SWR - you may have a GROUND LOOP that opened up. I can't stress this enough - but I've seen perfectly good HR2510's go into the trash heap because someone didn't bother to check the GROUND LOOP at the SWR card when they encountered problems they couldn't fix.
- If one of those "tabs" on the card was left open, the card then "floats" at whatever ground is present ON ONE SIDE OF THE CARD - making a tiny little antenna - and worse, a big mess for the MRF477 to get pummeled by stray RF and Poor SWR mis-match even when your EXTERNAL SWR meter shows everything is fine...
The SO-239 uses the Coax Center Pin.
- -CAUSING ANOTHER TYPE OF SWR HEADACHE OPEN LEAD TO COAX
- even when EXTERNAL SWR meter shows everything fine...
That condition can also destroy this radio.Rear nut? You can use a wrench - two is needed - one to "hold the thread" while the other turns the nut to press fit the connector to the rear panel. The smaller wrench uses the threaded flat to hold and the other tightens or loosens - depending on your replacing or installing.
Hope this helps!
.
thanks this does actually help alot i think what i was seeing was open lead swr as when i moved the coax around power would go away and comeback. i did test that coax on a few other radios one of them being another 2510 and they acted fine
Unsolder one of the two "Ground" tabs - and check board foil ground to the rear "big T" foil trace - check for continuity - use one of the traces that solder to the "T" for this - you are just verifying the "loop" isn't open or the board got cracked.
You can check those Green Circled spots to any CASE IF/RF can which is foil board ground
- look for continuity.
Resolder the tab lead back to foil ground , unsolder the other one and check again - same way.
If both check out - the "T" Ground is not the culprit. You may want to recheck the SO239's ability to pass RF from the antenna lead back at the main PCB - see the post above for details - that lead needs to show good thru the center of the SO-239 into coax - you can use a short 3 foot jumper to verify the center pin is making contact all the way back to the antenna lead pigtail from the Main PCB as a continuity check.
In fact the coax jumper can help you troubleshoot the SWR issue by doing the continuity checks like above - thru the coax to the case of the radio (back panel may be ok, but check side panels the steel ones too) So Shield of coax at the free end, to ground of case at the radio - should be same ohmic reading as with the two test leads touched together (Your Zero-set reading) if you get higher ohmic like 2 ohms or higher, you have a connector issue. Same can be done to the CENTER to Antenna Pigtail - again check to see if it's good connection. Wiggle connector to see if it's center lead is loose.
These are simple checks that can help you figure out what is causing your high-intermittent SWR issue.
You can check those Green Circled spots to any CASE IF/RF can which is foil board ground
- look for continuity.
Resolder the tab lead back to foil ground , unsolder the other one and check again - same way.
If both check out - the "T" Ground is not the culprit. You may want to recheck the SO239's ability to pass RF from the antenna lead back at the main PCB - see the post above for details - that lead needs to show good thru the center of the SO-239 into coax - you can use a short 3 foot jumper to verify the center pin is making contact all the way back to the antenna lead pigtail from the Main PCB as a continuity check.
In fact the coax jumper can help you troubleshoot the SWR issue by doing the continuity checks like above - thru the coax to the case of the radio (back panel may be ok, but check side panels the steel ones too) So Shield of coax at the free end, to ground of case at the radio - should be same ohmic reading as with the two test leads touched together (Your Zero-set reading) if you get higher ohmic like 2 ohms or higher, you have a connector issue. Same can be done to the CENTER to Antenna Pigtail - again check to see if it's good connection. Wiggle connector to see if it's center lead is loose.
These are simple checks that can help you figure out what is causing your high-intermittent SWR issue.
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so your saying lift the one ground tab at a time and check for continuity between the case or foil ground and the ground tab i lifted correct? and i actually just put the radio back together installed the mica insulator on both final and ground plus a new so 239 connecter and AM still works great and ssb has swr spikes. and the power modulator that mounted on the side of the case gets hot after transmitting in ssb the happend before taking the radio apart
i did hook a 3 foot jumper and ran one lead to the jumper and the other to the case and the grounding tabs on the swr card plus the for spots mentioned up top all seem to check out might wait until i can get a desoldering gun to desolder the ground tabs on the swr card i have desoldering wick but i think it would be better if i could get a decent desoldering gun