Posted on behalf of n0th1n6 (new user)

You are always most welcome, anytime.

Very best regards from Harry - SM0VPO

Admin wrote:

Follow this link.
My 500mW RF linear amplifier will get you to 30MHz, although you only need the driver stage.

BR Harry - SM0VPO

Thanks Harry. Your project page seem to always have what I need. I didn't notice that 500mW HF linear because I though it was AF section. I have built almost the same but on the output, I have a 6.8k to the Vcc and 680R on emitter to ground. The base also has 51k to Vcc and 5.1k to ground. Input cap is 100n. I am really having hard time grasping this things haha. Ill go back to experimentation later tonight.

Thanks and VBR,

Noli - 4G1ZYS

n0th1n6 wrote:Although I'm still interested on how to properly amplify the signal from the generator.

Follow this link.
http://www.mouser.se/ProductDetail/Qorvo/QPA4563ASR/?qs=sGAEpiMZZMsHFhLSzabyWfAY7XKEnRiZIIoXVxBmP35GsFok5RUe0A%3d%3d
20dB gain from DC to 3.5GHz, and for only US$3. Can't go wrong with that.

To do it now, you could use a complementary audio amplifier, and modern AF transistors will get you to well over 1MHz. My 500mW RF linear amplifier will get you to 30MHz, although you only need the driver stage. But these two solutions may give a bit of distortion. It depends on what you want.

BR Harry - SM0VPO

Hi Harry,

I'd go with the GDO as a source. Will start to build one tonight. Although I'm still interested on how to properly amplify the signal from the generator.

As for the contact, I still do not own any HF transceiver at the moment. I am looking forward to buying a BitX40 soon. But that is 40m only. Have a nice stay in Spain.

Thanks and Best Regards,

Noli - 4G1ZYS

Hello Noli,
With the quick-receiver you need about +7dBm (500mV RMS) from your generator to make the diodes conduct and give some form of conductivity.

Did you use germanium diodes (looks like it in the picture)? They only need about 0.11v RMS to conduct. Your generator may not be giving sufficient output.

The picture looks good and the coil also looks good. You should be getting huge signal converion if you have sufficient output from your generator. Perhaps you need to amplify the generator output?

The method of construction is perfect for this project and HF bands. I can see you used more that 17 turns, but that should not affect anything below 15 MHz (at worst). You should be able to get stuff on 7MHz broadcast band, and even the MF and LF bands.

No, your generator is weak. I used to drive this QR with my GDO and that gave excellent results.

Ok, I will look you up in QRZ.COM. Perhaps we can even make contact on 14MHz or 18MHz sometime? I go to Spain in three weeks, and there I have a lovely 1/2-wave dipole for the whole HF band.

BR Harry

Hi Harry,

Because of this, I now register to QRZ .

So I have built the Quick RX. Let me show you the picture. I still have doubts at my construction



It's more than 17 turns because I cut enamel wires a few cm longer.

When I hook up the signal generator, I hear whistles on spots starting at 100kHz until around 300kHz. Past that range, whistling on some spots still occur but too faint. I even set the volume control of the audio amp to max. I think I need a better signal generator. The one I am using says 100mV up to 30MHz but it is not true. Even at 7MHz, it already dropped to 40mV.

Thanks and Best Regards,

Noli - 4G1ZYS

Hi Ivan,
I, too, found that a couple of years ago, and I had to recover my password then update my info to get the account back and visible.
interesting that when i operate in the field, I can almost always find active station in QRZ.com, so i thought it was worth the effort to re-register.

I have a lot more time for social media these days :-) including this forum  

BTW, I have also found a cheap source of 455kHz osc/IF can sets for US$1.80. I have posted the link in the WANTED/FOUND section  

BR Harry

Hi all,
not every ham has his account on QRZ.COM. I tried to seek myself. What response did I get?
"Your Search by Callsign found no results for OK1SIP
OK1SIP looks like a callsign from Czech Republic "

I remember I registered on QRZ.COM many years ago. The registration must have expired.

VBR from Ivan

Hi Harry,

I am from the Philippines. Deeco is a known shop here but it is still a walk-in only shop. There is no website or online store yet. I suspect they still have old parts because during the days they order truck loads of each part.

As for the callsign, 4G prefix is new. We run out of DU, DY, and DV prefix. I had my license 2 months ago but i will confess, I have been using tranceiver since 2000.

I will start the synthesized rx soon but i think i will prioritize quick rx, gdo, and synth rx in that order.

Thanks and 73s,

Noli - 4G1ZYS

n0th1n6 wrote:Shops name by the way is Deeco.

Hi Noli,
Deeco, I tried to look you up in QRZ.COM but only got:

Your Search by Callsign found no results for 4G1ZYS
4G1ZYS looks like a callsign from Philippines

I figured that Deeco is close to your home, but that doesn't help. What town is Deeco in?

BR Harry

Hi Harry,

I walked in on that shop. As far as I know, they don't have an online store yet. They ship locally but you have to call their land line. Shops name by the way is Deeco.

Best Regards,

Noli - 4G1ZYS

n0th1n6 wrote:Below is what I got from yesterdays trip to the shop. I now include GDO2 in future project.

Hi Noli,
Which shop did you get those from?
Do you have a link?

BR Harry

Admin wrote:

Quick antenna? For VHF there is no problems, just look at my VPOLE ANTENNA.

For HF reception I found that a 50pf capacitor conected to one terminal of the landline (twisted-pair) telephone network will get you a LOT of HF activity, from VHF to 30MHz, perfect to check receivers. Do not transmit into it, though

BR Harry

Hi Harry,

Currently using Diamond X50 for VHF. My interest is HF actually, the 40m band. Funny because in my place, after all this advancement in technology, we never hand a landline so nothing to use for quick antenna. I might tie a wire to a tree (post) and see if it will work.

Hi Ivan,

Yes, those are AM coils. I will try to open and re-purpose the former and can.

Thanks and Best Regards,

Noli - 4G1ZYS

n0th1n6 wrote:It also need a quick antenna.

Quick antenna? For VHF there is no problems, just look at my VPOLE ANTENNA.

For HF reception I found that a 50pf capacitor conected to one terminal of the landline (twisted-pair) telephone network will get you a LOT of HF activity, from VHF to 30MHz, perfect to check receivers. Do not transmit into it, though

BR Harry

Hi Noli,
it is really nice. The screened coils are probably for AM radios and they may include a fixed capacitor. Red one was usually used for the local oscillator, white, yellow and black one formed a 455 kHz IF filter.

VBR from Ivan

They said, don't reply to your own post. But I have to update soo..

Below is what I got from yesterdays trip to the shop. I now include GDO2 in future project.

Hi Ivan and Harry,

I swear I've seen it somewhere haha. All is well now. I go back to the article and it indeed has the number of turn. Will rob a ferrite from one of those pc power supply lying around.

Im afraid testing will take another week. It also need a quick antenna.

Thanks and Best Regards,

Noli 4G1ZYS

Hi Ivan and Noli,
I think I have used both expressions in previous posts. I think Noli has been reading some history on the board. When I documented the quick receiver I wrote 17 turns.

It does not really matter much as you can use just about any grade of ferrite and anything from 4 turns to 100 turns per winding and get almost exactly the same result. It is a transformer and the output load impedance is reflected back at the input. If the coil has too low inductance then it will give poor oerformance at 1.8MHz/3.5MHz, and if there are too many turns it can be bad at 30MHz/50MHz areas. You will need more turns if you go down to VLF, as Barry did.

Ready-made 2.2mH "common mode" filter inductors (see Densil's 2-tube TX project) are as common as dirt, and they have about 17 turns per turn, and two windings already wound for you :-)  That makes the project even quicker ;-)

Best regards from Harry SM0VPO

Hi Noli,
where did you see the words "several turns"? I found exactly 17 turns recommended in the "Quick Receiver". Maybe Harry will give you a more exact response.

VBR from Ivan

Hi Ivan,

More testing seems to confirm that it can go down to 1uH. I have tested 10uH with no issue.

Back to the number of turns, since inductance is not specified, can I just make say max turn until I fill all the space available?

Thanks and Best Regards,

Noli - 4G1ZYS

Hi Noli,
this looks much better  
The LC100-A meter priced at cca 15 USD seems quite cheap. It should have a 1 uH low inductance limit, which is nice. I myself ordered one, although I have a good automated LC bridge already. I intend to use the LC100-A for mobile use.

VBR from Ivan

Hi Ivan,

Now that you mention that banggood LC meter, I took out mine and tested again. Now I feel like a liar because I was able to measure 20uH (smallest I can easily find). Maybe, when I'm testing the inductors I pulled out from a junk board, it was already defective.

Here is what I use to test components. The inductor below is a 100uH read as 80uH.

Hi Noli,
the dot in a coil in a schematic usually means the beginning of the winding.
My experience is that measuring small inductances is extremely useful for work at RF. 220uH as the lower limit seems too much. What about something like this:
https://www.banggood.com/LC100-A-LC-Meter-1uH-100H-Inductance-1pF-100mF-Capacitance-Table-p-1056801.html ?

VBR from Ivan OK1SIP

Admin wrote:No problem. But it would be no cost or effort for me to just put a slack-handfull of cans in the post to you. 

Hi Harry,

Really appreciate your offer. I will let you know this coming sunday.

With regards to the Quick RX, the dot in the inductor means cw/ccw? And several turns could be 10 or 100? I think I can measure inductance with a kit bought from china but I'm afraid it has very limited range. I cant measure 100uH but 220uH and up is OK.

Thanks and Best Regards,

Noli - 4G1ZYS

n0th1n6 wrote:As much as I would like to have some of your IF cans, it will not be cheap to ship here in my country.

Hi Noli,

No problem. But it would be no cost or effort for me to just put a slack-handfull of cans in the post to you. Most of the cans I have are in Spain, but I could send you a dozzen or so (foc).

If you have any further problems with passwords and access then just drop me a line and I can fix it.

Very best regards from Harry - SM0VPO

Thank You Harry for activating my account and transferring our email conversation here in the forum. As much as I would like to have some of your IF cans, it will not be cheap to ship here in my country. I think I have to either buy those old AM and FM RX kits from electronics shop or ask them to dig from their old stock if there is still anything left. I suspect the latter have very little chance. I really appreciate your offer and if I had the chance, say Ericsson send me to Sweden, I grab one of those .

As for the ADS9850, I plan on re purposing arduino minis that I have lying around. I have also salvaged some LCD from printers and old Alcatel telephone set that I can use for frequency display. There is also local e-store that has the module for 14USD so I am now contemplating if I still want to make a pcb or just buy one that is ready made.

For the quick RX, I might start with it this coming weekend after the trip from electronic shops.

Below is my last set of IF can salvaged from a junk transistorized radio. I had fun soldering this so I don't feel like re-using the IF cans 

Hi Noli,
Your account has been activated (should have been automatic!). Please test you login and let me know it works now. Interesting that there were two ther people who tried to register in the past 2 months. They have also been activated. I must look into this.

Yes, that signal generator should be just perfect. Just switch OFF the internal modulation and tune it to the receive frequency minus (or plus) the Intermediate Frequency.

Also, if you look on the pages you will see a "Quick Receiver" which is perfect with this generator, and the receive frequency is the generator frequency (no IF offset). This will get you receiving quickly while you build the IF amplifier.

As regards the ADS9850 DDS signal generator, I have a PCB drawing and SW for that DDS generator, using a 16F624 PIC processor chip. Uses an LCD display for frequency info, and can also be programmed with the IF offset. Let me know if you want the data and I can post it on the homepages so all can share it.

If you want any IF cans then I can send you a few. A good friend once sent me loads of them and I have helped many people with them for my projects. Just let me know how many you want and give me a postal address (by e-mail) to which I can send them. If you want the PIC programming then I can blow one of those for you.

Best regards from Harry - SM0VPO

Hi Harry,

I tried to register n0th1n6/xxxxxxxxxxxxxx as my username/password in the forum. Please use the same to create one for me if that failed. It may have been already created in the forum but awaiting activation.

Now that the inductor mystery has been cleared, I will start the build process by finding donor IF cans. I know they are not that popular nowadays but I think it is still the best as it already has the screen.

For the synthesizer, I intend to use the ADS9850 DDS signal generator. I have seen some project that use this with success, for example the Minima by VU2ESE. I will figure this out on how to incorporate to the RX. The ICs in your original synthesizer is also hard to find here in the Philippines, the reason why I am motivated to find an alternative.

Final question. Can a lodestar signal gen be used in place of the synthesizer for the LO so I can test without having to build the synth first? Below is the signal gen spec

• Frequency range: (up to 450MHz on 3'th harmonics)
  
  
  
  • A: 100KHz ~ 320KHz.
    
  • B: 300KHz ~ 1,100KHz.
    
  • C: 1MHz ~ 3.3MHz.
    
  • D: 3.0MHz ~ 11MHz.
    
  • E: 10MHz ~ 35MHz.
    
  • F: 32MHz ~ 150MHz.
    
  
  
  
  
• Frequency accuracy: ±5%.
  
  
• RF output: 100mVrms, approx (up to 35MHz unloaded).
  
  
• Output control: High-low switch and fine adjuster.
  
  
• Modulation:
  
  
  
  • INT. 1KHz (AM) 30% approx.
    
  • EXT. 50Hz ~ 20KHz, at less than 1Vrms input.
    
  
  
  
  
• Audio output: 1KHz, Min. 2 Vrms.
  
  

Thank You and 73's,

Noli - 4G1ZYS

1 - PROBLEMS registering - give me a desired username and password and I will create and activate the account for you.

2 - That receiver uses a limited coverage synthesiser, but the object of the project is to have an inductive/capacitive tuned circuits, without any inductance after the IF amplifier. This gives you a high gain without the possibility of inductive coupling input and the input and output of an amplifier (avoids instability).

It is important that the tuned circuits are well screened from the outside world and that each coil is properly grounded without any inductance in the connection leads. you can do this by fitting the coils in screened cans (rewinding IF cans?) AND physically building the filter inside a metal tin, such as a "strepsils" throat tablet tin. I suggest that you mount the inductors horisontally on copper-clad board, you can also use copper board to make partitions to form the screeneing cans :-)

Each coil should be individually screened, otherwisae there will be too much coupling, causing the bandwidth to be far too wide. Now that I look at the circuit diagram I see that I could have drawn them a bit better, and it looks as though L2 and L3 are in the same screen - they are NOT. This would also explain the problem another guy had with this project, but he was not able to clarify the questions as well as you.

Please give me you password and username and I will create the account. I will also post this question and my answer on your behalf. You can change your password at any time, or ask me to reset your password.

Very best regards from Harry Lythall - SM0VPO
[url=tel:+46 73 629 50 02]+46 73 629 5002[/url]

I apologize first for sending an email. I know you recommend to ask question in the forum but I am not lucky I guess because I attempted several times but registration was not approved yet.

I plan on building the Synthesized HF receiver but since inductor is still mysterious to me, I want to ask some question. When you say screened, how do I screen it? I see 2 inductor (L2, L3) and (L4, L5) both screened in a slug tuned former. I know slug tuned former and I think IF transformers are slug tuned as well. If I am correct, is L2,L3 and L4,L5 in just one former and adjusted simultaneously?

Best Regards,

Noli