Date   

Re: hot glue toroids

Graham, VE3GTC
 

Depends on what you what as far as stability goes.

Do you want able to survive the vibration of a rocket launch or just a bit of small knocking about in daily use in the shack or an outing in the park?

Hot glue is used by many, cheap and easily available and it does work. Moderately easy to remove if need be.

Proper electronics conformal coatings are also a good choice, not necessarily cheap nor easily available. You usually need to go to an electronics supplier but there are some brands and types to be found on eBay and Amazon.  The acrylic types are probably the best for the home constructor. Not so easy to remove if need be.

You could also use plain old white PVA craft glue. also very cheap and easily available. Water soluble and fairly easy to remove if need be.

My favourite is common clear nail polish or coloured if you prefer. Coat the wires on the toroid to hold in place and let it "pool" around the base to provide the support and stability you want. One good coating is usually sufficient, sometimes a second depending on wants and needs. Easy to remove with nail polish remover. My current favourite is "Tough as Nails with Teflon".

I would stay away from things like silicone and Shoe Goop type of products. Tried them, moderately difficult to use and difficult to remove.

And always remember, cleanliness, cleanliness, cleanliness.  It is important to start with a clean PCB assembly for any of these solutions to work well; free of any kind of oils and fluxes otherwise adhesion to the PCB assembly will be hit and miss and often more miss than hit. Use common isopropyl alcohol  ( i.e. IPA or rubbing alcohol ) but get the kind without additives like lanolin and the higher the percentage of IPA the better. And for stubborn oils and fluxes adding little dash of acetone is beneficial. MG Chemicals heavy duty flux remover is mostly IPA and acetone. I use common pharmacy high percentage IPA for most jobs and add a dash of acetone for the tough ones, about 9 parts IPA to 1 part acetone works for me and I use a can compressed air to lightly blow dry and sometimes follow up with a gentle warm heating with a hair dryer to help drive off any residual moisture.

cheers, Graham ve3gtc







On Thu, Feb 27, 2020 at 12:19 PM Alan G4ZFQ <alan4alan@...> wrote:
> I think I have heard somewhere of folks hot gluing toroids in place to add stability.

Matt

I've done it on some boards, not noticed any problems.
Cut a small piece, melt with soldering iron.
I guess someone might say it could affect the inductance/Q but I've not
known anyone prove it. I reckon a little makes no appreciable difference.

73 Alan G4ZFQ







Re: hot glue toroids

ae1ct1998 <AE1CT1998@...>
 

I put a dab of hot wax on my toroids with no problems.


On Thu, Feb 27, 2020, 07:44 Mike Besemer - WM4B <mwbesemer@...> wrote:

Has anyone measured changes in Q/inductance before/after applying a sealant such as clear nail polish to a toroid?


Mike - WM4B

On February 27, 2020 at 7:19 AM Alan G4ZFQ <alan4alan@...> wrote:
I think I have heard somewhere of folks hot gluing toroids in place to add stability.

Matt

I've done it on some boards, not noticed any problems.
Cut a small piece, melt with soldering iron.
I guess someone might say it could affect the inductance/Q but I've not
known anyone prove it. I reckon a little makes no appreciable difference.

73 Alan G4ZFQ





Re: hot glue toroids

Mike Besemer - WM4B
 

Has anyone measured changes in Q/inductance before/after applying a sealant such as clear nail polish to a toroid?


Mike - WM4B

On February 27, 2020 at 7:19 AM Alan G4ZFQ <alan4alan@...> wrote:
I think I have heard somewhere of folks hot gluing toroids in place to add stability.

Matt

I've done it on some boards, not noticed any problems.
Cut a small piece, melt with soldering iron.
I guess someone might say it could affect the inductance/Q but I've not
known anyone prove it. I reckon a little makes no appreciable difference.

73 Alan G4ZFQ





Re: hot glue toroids

Alan G4ZFQ
 

I think I have heard somewhere of folks hot gluing toroids in place to add stability.
Matt

I've done it on some boards, not noticed any problems.
Cut a small piece, melt with soldering iron.
I guess someone might say it could affect the inductance/Q but I've not known anyone prove it. I reckon a little makes no appreciable difference.

73 Alan G4ZFQ


hot glue toroids

Matthew Halsey <rftb_cowboy@...>
 

While doing some diagnostics on my QCX-40, I noticed that several, if not all, the toroids are really only held in place by the very thin magnet wire soldered to the board.
I think I have heard somewhere of folks hot gluing toroids in place to add stability.
Am I correct?
Any special considerations that I need to bear in mind if I do this?

Matt
KC3OIV


Re: FedEx express shipping 3-4 days now available; and other shipping changes

danielu@upcnet.ro danielu@upcnet.ro
 

Thousands of thanks for this decision.
Daniel Ungureanu
YO8SAK


Re: FedEx express shipping 3-4 days now available; and other shipping changes

Hans Summers
 

Hello Lex

Thanks for the info. 

The FedEx shipping already sends everything as package. So I think we have no problems here. We also put the CN22 on all normal post office packages so hopefully this makes no problem for the non-FedEx case too... fingers crossed! 

Since I made the announcement on FedEx availability yesterday, 6 out of 10 orders have chosen FedEx so early indications are that this shipment option will be popular. We have a FedEx collection this afternoon for these! 

73 Hans G0UPL
http://qrp-labs.com

On Thu, Feb 27, 2020 at 11:13 AM Lex PH2LB <lex@...> wrote:

Well Hans, that is a good explanation about the shipping cost. And you shouldn't lose money on small orders (i think you don't have venture capitalist backing you up, like Amazon had).

But it's a good thing you added the FedEx option. I think it's the perfect shipping option for hamradio clubs with joined purchases and club projects, and OM's who want to buy multiple products at ones. 

Additional remark : The Union Postale Universelle (UPU) has determined that of 1 jan 2020 envelops containing products and are address outside the country, have to be marked as packages (and paid for it like a package).  I don't know if the postal service from Turkey is member of the UPU but in the Netherlands (PostNL) they are all-ready forcing it (a lot of webshops complain about the extensive cost rise).  

73 Lex PH2LB


Re: FedEx express shipping 3-4 days now available; and other shipping changes

Lex PH2LB
 

Well Hans, that is a good explanation about the shipping cost. And you shouldn't lose money on small orders (i think you don't have venture capitalist backing you up, like Amazon had).

But it's a good thing you added the FedEx option. I think it's the perfect shipping option for hamradio clubs with joined purchases and club projects, and OM's who want to buy multiple products at ones. 

Additional remark : The Union Postale Universelle (UPU) has determined that of 1 jan 2020 envelops containing products and are address outside the country, have to be marked as packages (and paid for it like a package).  I don't know if the postal service from Turkey is member of the UPU but in the Netherlands (PostNL) they are all-ready forcing it (a lot of webshops complain about the extensive cost rise).  

73 Lex PH2LB


Re: QCX 40 NO POWER OUTPUT #40m #qcx40 #problem

Greg Walters
 

Thanks Alan,

I should clarify that this rig worked perfectly until I let a friend borrow it. He plugged it in and tuned his antenna, but discovered it didn't have any power output. He tried my 20 meter rig also, and the same thing happened there. I did a "factory reset" on the 20 meter QCX and went back through the alignment of it. Not much changed, and it started putting power out. 5.3 watts or so with 13 volts. 

Since that worked on the 20 meter, I tried the same on this 40. I needed a lot of adjustment with the alignment. But still doesn't have any power out. 

I just checked receive, tunes appropriately, and receives nicely as before. I found a great very strong signal running 15-20 wpm and the decoder only put Ts on the screen for each dit or dah. 

Just out of curiosity, I tried checking out the RF while connected to the antenna. When I did, and keyed up, I lost receive. I cycled the power and receive came back. I keyed while not in test equipment, and it kept on with the receive. When I went to the menu and selected RF, without even checking, as soon as I keyed, the receive went out. 

This is a very interesting issue. 
--
73,
Greg
KY4GW


Re: 20 meter QCX voltage

Albert Rowe
 

Hi Thanks for that Jim, yes I knew the supply voltage was on pin 8 stupid of me really, pin 2 and 7 should be 2,40 ish volts I think, must be as you said a soldering fault somewhere, I have all the drawings' ans schematic printed on A3 glossy paper a great help they are too, it's my brothers board, so I did not solder it up, also a few components in wrong places and a diode in the wrong way round, you get a bit circuit weary sometimes, time to buckle down again, thanks again.


Re: 20 meter cw rig #20m

Don Blachura
 

Hello Ron,
Took two windings off L1,2,3 and one off L4.
Now getting 4 watts on meter.  Thanks for the great tip.

Don..w2xb


Re: 20 meter QCX voltage

James Daldry W4JED
 

Hi, Albert

If you print off the schematic and look at the lower right corner, you see that all the "square box" chips are connected to +12 volts at pin 8, with pin 4 at ground. IC4 is a collection of switches which pass the DC voltage from R1 and R2 through to C43 through 46, about 2 1/2 volts. Now - we're not working with automotive light bulbs here - these chips have virtually infinite input impedance. With no resistors to ground, there's no voltage drop up to and including IC9 pin 1. Since all these stages are voltage followers, you should see approximately 2.5 volts boringly anywhere you poke. Any "high" voltages indicate an open feedback loop - open resistor, or more likely, bad solder connection. On each IC, compare voltages between pin 1 and 2, and pin 5 and 6 . Pin 1 and 2 voltages should be identical to each other on the same chip, and pin 5 and 6 voltages also identical to each other. Find the one that's not, and you've found where the solder needs fixing, a 10 meg resistor has been substituted for a 10K, etc. Something is open in the loop.

73

Jim W4JED

On 2/26/20 8:36 AM, Albert Rowe wrote:
HI, I'm getting some high voltages on IC5-9 on pin 2,7 and others just under the supply voltage, I have traced back through R17 and r24 trim pots but get lost in the myriad of components, if I remove IC5 and probe the carrier  pins the voltages drop right down, I have looked at the schematic but can not see where it is picking up the 12= volts, I can't see any bridges and so on, so at a loss, any thoughts, thanks.


Re: QCX 40 NO POWER OUTPUT #40m #qcx40 #problem

James Daldry W4JED
 

Hi, John

The voltage chart was written using the on-board "voltmeter". Since it has a relatively low input impedance it will pull down any voltage that has a high impedance source. Trust me - the actual voltage on pin 3 of IC8, as with any op amp wired as a voltage follower, is within a few microvolts of the voltage on pin 2. If you were to put a second voltmeter on IC8 pin 1 or 2 (they are connected together) while checking pin 3 with the on-board voltmeter you would find that all 3 pins would be at the same voltage - within microvolts. The reason the on-board meter is used is that that is the meter Hans knows that every QCX builder has on hand.

These op amps used in these radios have a DC open-loop gain of 140 db. That's more than the path loss between the 50000 watt FM radio station you are listening to and your radio antenna. Any difference in DC voltage between pin 2 and pin 3 is magnified by 140 DB.

73

Jim W4JED

On 2/26/20 8:27 AM, John Brock wrote:
It seems to me the voltage measurement table in the instruction manual is off in a  few instances. I am  looking through the receiver function on my 20M QCX. It seems too quiet to me. Don't get enough volume. Hear a few faint signals. I will admit my Icom isn't hearing a lot on 20M either..

So What confuses me on the voltage measurement table is the expected readings on the differential amps in the RCV chain. Like IC6, IC7, IC8 pins 2 and 3 are inputs to the amp. I think they should be equal. Same with pins 5 and 6. The manual says IC8 pin 2=2.46 while pin 3=0.65 for example.

Can someone set me straight on this?

Thanks
John
WA8US


QCX background videos on youtube

Peter
 

Hallo,
I found on Youtube a very good serie (Part 1-7) from NA5Y. He explain in details all signal processing details from the QCX.
I learned a lot from that.
Link: https://www.youtube.com/user/caliphaxable/videos

Peter OE1OPW Vienna


Re: 20 meter QCX voltage

Alan G4ZFQ
 

HI, I'm getting some high voltages on IC5-9 on pin 2,7 and others just under the supply voltage, I have traced back through R17 and r24 trim pots but get lost in the myriad of components, if I remove IC5 and
Albert,

First, look at the voltage table in the manual.
Make your own list.
Going through the circuit using the schematic you need to know where in the chain something begins to go wrong.
Show us the list. Actual voltages help us, tell us whether you are using a DVM or the built-in meter.

73 Alan G4ZFQ


Re: QCX 40 NO POWER OUTPUT #40m #qcx40 #problem

Alan G4ZFQ
 

. Like IC6, IC7, IC8 pins 2 and 3 are inputs to the amp. I think they should be equal. Same with pins 5 and 6. The manual says IC8 pin 2=2.46 while pin 3=0.65 for
John,

They are equal.
The manual also says that readings were taken using the internal meter of the QCX that loads voltage sources and shows lower readings. Look at the schematic, IC8 pin 2 connects to IC8 pin 7 through 2 47K resistors. Therefore the simple built-in meter reads low because it's input resistance is only about 13K.
Ohm's Law my be used to confirm this.
A modern DVM has 10M input impedance giving readings that are very very close to actual voltage.

73 Alan G4ZFQ


20 meter QCX voltage

Albert Rowe
 

HI, I'm getting some high voltages on IC5-9 on pin 2,7 and others just under the supply voltage, I have traced back through R17 and r24 trim pots but get lost in the myriad of components, if I remove IC5 and probe the carrier  pins the voltages drop right down, I have looked at the schematic but can not see where it is picking up the 12= volts, I can't see any bridges and so on, so at a loss, any thoughts, thanks.


Re: QCX 40 NO POWER OUTPUT #40m #qcx40 #problem

John Brock
 

It seems to me the voltage measurement table in the instruction manual is off in a  few instances. I am  looking through the receiver function on my 20M QCX. It seems too quiet to me. Don't get enough volume. Hear a few faint signals. I will admit my Icom isn't hearing a lot on 20M either..

So What confuses me on the voltage measurement table is the expected readings on the differential amps in the RCV chain. Like IC6, IC7, IC8 pins 2 and 3 are inputs to the amp. I think they should be equal. Same with pins 5 and 6. The manual says IC8 pin 2=2.46 while pin 3=0.65 for example.

Can someone set me straight on this?

Thanks
John
WA8US


Re: FedEx express shipping 3-4 days now available; and other shipping changes

Hans Summers
 

Hi George

As far as I know, FedEx/TNT is available to anywhere. Most countries will not have any tax liability but I do not know for sure about Mexico. 

73 Hans G0UPL
http://qrp-labs.com

On Wed, Feb 26, 2020 at 3:43 PM George Korper <georgekorper@...> wrote:
Is the FedEx option available to Mexico?
Fedex is much better for me, as they have 
a customs clearance, procedure that allows payment by credit card. 

On Wed, Feb 26, 2020 at 5:32 AM Hans Summers <hans.summers@...> wrote:
P.S. additional to the below... in some cases we are able to ship to US customs domestically from some limited stock on MO. This is not guaranteed for US customers, it is at our discretion based on whether or not the order items are available in MO or not. In this case, if the customer ordered using FedEx then I will ship domestically via USPS from MO and refund the difference in costs. If the customer ordered the usual way then it's all the same as now. 

73 Hans G0UPL 

On Wed, Feb 26, 2020, 12:38 Hans Summers via Groups.Io <hans.summers=gmail.com@groups.io> wrote:
Hi all

I have always collected statistics on shipping times to help manage people's expectations, see http://qrp-labs.com/shipping - but, nevertheless in these days of Amazon Prime etc., people sometimes have high expectations! Several people have requested faster shipping options but until now it has been too expensive. 

However, I have now reached an agreement with FedEx (TNT) on a deal for fast shipping of QRP Labs products at reasonable prices. I also tested it on two orders to US, and one order to UK. All three test cases arrived in 3 days exactly as predicted by the FedEx representative. So we will now offer this FedEx option, for people who wish to get their orders more quickly, in addition to the existing post office shipment option. To start with, FedEx local courier will collect from us on Mondays, Wednesdays and Fridays. Therefore, we will prepare all orders within 1 business day as usual, and then shipping via FedEx would take 3-4 business days (depending on what day you order). 

The prices for FedEx are higher, but not by a very large amount; in some cases the prices are almost the same. While post office pricing is adjusted in increments of 10 grams, the FedEx quotations are in increments of 0.5kg. There are no bad tax or VAT implications to choosing FedEx instead of the ordinary post office shipping. 

I have also analyzed the existing post office shipment prices and found that for small lightweight shipments the shipping amount charged by the QRP Labs shop doesn't cover the actual post office shipment cost, let alone the packaging materials. So in the case of some small orders I actually make a loss. To fix this I have now analyzed all shipment rates and increased the shipment price for lightweight orders. Some of the larger weight orders, the price has been REDUCED. 

However, I also decided to add a new cheaper shipment option, which is basic post office airmail shipment, with no tracking and no insurance. It should not be slower than the ordinary post office option, but, if it IS slow don't email me and ask me where it is, because it isn't tracked. This could be useful for people making small orders. 

Since FedEx is priced locally in euros, and the post office in Turkish Lira, I will have to review these prices from time to time and update them to take into account exchange rate fluctuations. 

So to summarize there are now THREE shipment options in the QRP Labs shop:

1) FedEx Express, 3-4 days; for orders weighing from 0 to 10kg

2) Normal Post office airmail, registered/tracked (the CURRENT option); for orders weighing 0 to 2000 grams

3) Post office airmail unregistered, no tracking, no insurance, no nothing - for orders weighing 0 to 250 grams

EXAMPLE 1, a small order (QCX firmware upgrade chip):
Order value $6
Shipment options:
1) FedEx 3-4 day express: $10.83
2) Post Office airmail $6.00 (current option, would previously cost $5.00)
3) Post Office airmail no tracking/insurance: $3.40

EXAMPLE 2, a QCX kit on its own:
Order value $49
Shipment options:
1) FedEx 3-4 day express: $10.83
2) Post Office airmail $6.96 (current option, would previously cost $7.00)
3) Post Office airmail no tracking/insurance: $4.35

EXAMPLE 3: a QCX kit with QLG1 GPS and 50W PA kits:
Order value $101.50
Shipment options:
1) FedEx 3-4 day express: $10.83
2) Post Office airmail $10.71 (current option, would previously cost $13.00)

73 Hans G0UPL


Re: FedEx express shipping 3-4 days now available; and other shipping changes

George Korper
 

Is the FedEx option available to Mexico?
Fedex is much better for me, as they have 
a customs clearance, procedure that allows payment by credit card. 

On Wed, Feb 26, 2020 at 5:32 AM Hans Summers <hans.summers@...> wrote:
P.S. additional to the below... in some cases we are able to ship to US customs domestically from some limited stock on MO. This is not guaranteed for US customers, it is at our discretion based on whether or not the order items are available in MO or not. In this case, if the customer ordered using FedEx then I will ship domestically via USPS from MO and refund the difference in costs. If the customer ordered the usual way then it's all the same as now. 

73 Hans G0UPL 

On Wed, Feb 26, 2020, 12:38 Hans Summers via Groups.Io <hans.summers=gmail.com@groups.io> wrote:
Hi all

I have always collected statistics on shipping times to help manage people's expectations, see http://qrp-labs.com/shipping - but, nevertheless in these days of Amazon Prime etc., people sometimes have high expectations! Several people have requested faster shipping options but until now it has been too expensive. 

However, I have now reached an agreement with FedEx (TNT) on a deal for fast shipping of QRP Labs products at reasonable prices. I also tested it on two orders to US, and one order to UK. All three test cases arrived in 3 days exactly as predicted by the FedEx representative. So we will now offer this FedEx option, for people who wish to get their orders more quickly, in addition to the existing post office shipment option. To start with, FedEx local courier will collect from us on Mondays, Wednesdays and Fridays. Therefore, we will prepare all orders within 1 business day as usual, and then shipping via FedEx would take 3-4 business days (depending on what day you order). 

The prices for FedEx are higher, but not by a very large amount; in some cases the prices are almost the same. While post office pricing is adjusted in increments of 10 grams, the FedEx quotations are in increments of 0.5kg. There are no bad tax or VAT implications to choosing FedEx instead of the ordinary post office shipping. 

I have also analyzed the existing post office shipment prices and found that for small lightweight shipments the shipping amount charged by the QRP Labs shop doesn't cover the actual post office shipment cost, let alone the packaging materials. So in the case of some small orders I actually make a loss. To fix this I have now analyzed all shipment rates and increased the shipment price for lightweight orders. Some of the larger weight orders, the price has been REDUCED. 

However, I also decided to add a new cheaper shipment option, which is basic post office airmail shipment, with no tracking and no insurance. It should not be slower than the ordinary post office option, but, if it IS slow don't email me and ask me where it is, because it isn't tracked. This could be useful for people making small orders. 

Since FedEx is priced locally in euros, and the post office in Turkish Lira, I will have to review these prices from time to time and update them to take into account exchange rate fluctuations. 

So to summarize there are now THREE shipment options in the QRP Labs shop:

1) FedEx Express, 3-4 days; for orders weighing from 0 to 10kg

2) Normal Post office airmail, registered/tracked (the CURRENT option); for orders weighing 0 to 2000 grams

3) Post office airmail unregistered, no tracking, no insurance, no nothing - for orders weighing 0 to 250 grams

EXAMPLE 1, a small order (QCX firmware upgrade chip):
Order value $6
Shipment options:
1) FedEx 3-4 day express: $10.83
2) Post Office airmail $6.00 (current option, would previously cost $5.00)
3) Post Office airmail no tracking/insurance: $3.40

EXAMPLE 2, a QCX kit on its own:
Order value $49
Shipment options:
1) FedEx 3-4 day express: $10.83
2) Post Office airmail $6.96 (current option, would previously cost $7.00)
3) Post Office airmail no tracking/insurance: $4.35

EXAMPLE 3: a QCX kit with QLG1 GPS and 50W PA kits:
Order value $101.50
Shipment options:
1) FedEx 3-4 day express: $10.83
2) Post Office airmail $10.71 (current option, would previously cost $13.00)

73 Hans G0UPL