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Gang, Does anyone have a good source of polystyrene capacitors to point me to? I need a 330pF cap for my current project, plus some spares :) Thanks... Alan, N8WQ

For Dave, AA7EE, and anyone else interested. I added about 3 mins at the end of this video showing that a toroid inductor in free space, vertically mounted on a PCB or horizontally mounted on a PCB has the same value. Now the nits are going for the 3rd and 4th digit, but fluctuations occur in the process of moving the toroid around and the spacing of the leads, thus the stray capacitance across the toroid causes a very minor change in the total. I will come back, after I finish this and ADC-40 (I'm doing the transmitter on the side), and do a complete video on toroids and why they are your friend. Once you get over the fear of winding the critters, you will use them everywhere. Well, almost..... <https://youtu.be/hAM1GkzwXB8> is the video by AA7FO for your entertainment. Watch the whole thingy and add a like to help an old man down on his luck. :-) And trying to get to a polished presentation sometime in the future. ciao, -- chuck adams, aa7fo QRP WAS 17m started Apr 2, 2025 WAS-17 QRP --> TX,FL,SC,GA,OK,AR,KS,AL,AZ,MN PA,CA,CO,WI,NE,ID,IL,NC,LA DXCC W,VE,JA,PY,ZL

Hello, Has anyone built the Simple SSB Transceiver that was shown on the blog and videos by Charlie Morris, ZL2CTM? Any suggestions? https://zl2ctm.blogspot.com/2021/01/simple-ssb-transceiver.htmlExp While I was trying to figure out what parts to get for various projects I wanted to work on, I realized that he was targeting a portion of 80m from 3.5 MHz - 3.6 MHz for the Band Pass Filter. But in the USA, I cannot do 3.5 MHz - 3.6MHz because no voice mode is allowed on that portion in my region. So, I need to move this up. And really, since this will be QRP, I do not expect to be getting any DX. And since I would share this with others, most hams would have a General. And I probably be more interested in targeting 3.8 - 4.0 MHz since this is where I hear most things anyways. So, this is where I need to learn how to do some of the same math he shows in his videos and his blogs to come up with his Band pass filter and IF Amp, etc. So, my center frequency for a band pass filter would be 3.9MHz. I looked on kitsandparts for their low pass filter board only and looked at it. And its links and led me to LTspice which is free so I downloaded it. So, I will try to reproduce what Charlie did first. Then proceed with my own stuff. I wanted to get toroids from kitsandparts. But now I am not so sure. Because now I will need to re-think the project for my region. If I go with the NE5334 preamp and LM380 amp ICs, they both can be found at Mouser in stock. Anyways, I like the video how he went about designing it. I like the use of the double-balanced diode mixers. Except, I want to do Manhattan construction on island pads instead of strip board. Anyhow, I maybe over my head and need to learn the electronics math and theory here. But I thought I would see if others have tried first. I am willing to do my home work. There are some radios I have built to compare to in the past like Curt's transceiver and Norcal 40A / 40B. So, there might be things there I could learn from including its book EOR. Charlie did mention he used the book Solid State Design for the Radio Amateur as a guide. Anyways, when I was at Adafruit, I noticed they were low on their Si5351A breakout boards. So, I ordered some. I liked how Charlie Morris showed the math how he determined values he got. So, that is a good starting point for me. I just got to figure out where he got that from. I even looked at the band pass/low pass filters at QRP Labs, but they take about a month to come from Turkey - and that is during good times. Not sure how things would be now. I do have a low pass/band pass filter from them for 40m but not 80m. But the filter is centered for CW - not SSB voice portions of the band. Thanks, Daniel KK4MRN

Alan, I feel for you bro. I ordered some valuable parts that I needed for projects from China before the tariffs kicked in. Envelopes worth $5.99, $6.34, $10.25, ... have been sitting at the airport and harbor in L.A.,CA for a week now and I am guessing that I will never see them. The backlog has got to be several warehouses full by now. The manpower alone has got be costing a lot more than the revenue for the small stuff. On 4/13/25 07:26, Alan N8WQ via groups.io wrote: > Gang, > Is anyone else having a delay in getting a shipment from Jameco? > I ordered parts on 3/25/25 and still have not received shipment. > Just curious... > > 73, > Alan, N8WQ > > On 4/11/25 17:04, k6whp via groups.io wrote: >> In keeping up with the mob, I had been buying my trimmers from >> JameCo. They are the ceramic ones and -- importantly -- a slot >> screwdriver fits and can turn the little buggers. (Done with the >> little brown plastic turdballs!) >> At increments of 10, they are 99 cents and at 100 are 89 cents. >> Be warned and be ready to order $20 of stuff otherwise they tap you >> for the difference. >> -- >> William, k6whp >> -------------------- >> "Cheer up, things could get worse. So I cheered up and things got >> worse." >> > > > > > -- chuck adams, aa7fo QRP WAS 17m started Apr 2, 2025 WAS-17 QRP --> TX,FL,SC,GA,OK,AR,KS,AL,AZ,MN PA,CA,CO,WI,NE,ID,IL,NC,NY,AL DXCC W,VE,JA,PY,ZL

I am building an Ozark Patrol regen. The stock tuning range is very large and I would like to limit it. By default, there is a SPDT switch that adds a parallel capacitance for a second range. My goal is to align the two ranges with the 20 and 40 m bands. Math shows that I need two fixed capacitors (one in series with the tuning, one in parallel with that) for each band. My thought is to replace the SPDT with a DPDT. I would build the circuit for 20 m and the switch poles would select in the appropriate differences to each fixed capacitor. Does this seem reasonable? Is this how it's done?

I downloaded the SP-1, 20M manual just now. Thanks, Chuck! https://archive.org/search?query=ohr+spirit+1 Steve AA7U

https://www.aliexpress.us/item/2251832645851677.html?ug_edm_item_id=2251832645851677&pdp_npi=4%40dis%21USD%21%2417.00%21%2417.00%21%21%21%21%21%402151e05a17444595335345189d181e%2165026062923%21edm%21%21%21&edm_click_module=item_detail&edm_log_data=edm-item-list-one-column.store-product-log-link&tracelog=rowan&rowan_id1=aeug_edm_84139_1_en_US_2025-04-12&rowan_msg_id=3212biz_search_product%3A0%3A0_577655577%24d173c597c1fe471fbc2d817627cca52e&ck=in_edm_other&mem_info=Kh9KBwMNoU8nqYqW8afaqA%3D%3D-100103-aeug_edm_84139-NeUIED0Kpdu1EGthwcNhm%20OAyttfpOfUucGiWZhD0C8%3D&gatewayAdapt=glo2usa

It appears that most of the chips, transistors, electronic parts are now exempt from the tariff. Mostly I believe codes 8541 and 8542 affect us. https://content.govdelivery.com/accounts/USDHSCBP/bulletins/3db9e55 Updated april 11th. ?

https://www.hanssummers.com/101/1011.html -- Ryan Flowers - W7RLF https://MiscDotGeek.com W7RLF Prototyping Boards MiscDotGeek YouTube Channel

Hi Ross, On mine, the Low band tunes 3.90-5.24 MHz; High band tunes 5.46-- ~19 MHz, as you note at least the High band is very wide tuning. Your scheme would probably work but I predict it will take a lot of experimentation to achieve it. Good luck and please let us know how it all turns out. 73, Steve AA7U

As some of you may be aware, the president has eliminated the de-minimis tariff exemption for China and Hong Kong. Under the executive order, packages coming through the international postal network will either be subject to a fee of 30 percent of the value of the goods, or $25, rising to $50 in June. Whichever is greater. This means the duty will be $25.00 for packages from these countries from May 2, 2025 and $50.00 from June 2, 2025 Onwards. Relevant news article: https://www.nytimes.com/2025/04/03/business/trump-de-minimis-china-shipments.html This means no more inexpensive printed circuit boards from Chinese manufacturers such as JLCPCB and PCBWAY and no more inexpensive parts from LCSC or Aliexpress. The only way we'll get inexpensive circuit board fabrication in the future is if some US-based circuit board manufacturer decides that the hobby market is big enough to service. Of course JLCPCB et. al could open a plant in another country, but that would be a risky proposition. The de-minimis tariff exemption could be eliminated from other countries in the future. So if you have any PCB designs ready or parts needs to submit it would be prudent to submit them soon to take advantage of the low costs before the de-minimis tariff ends. You also should make sure that your design ships out before the middle of April so that it doesn't get held in customs for duty payment. If this de-minimis exemption isn't relaxed by the president, then guess I'm going to have to find something else to occupy my time for the near term as these increases are going to make homebrewing using fabricated PCB's too expensive. Steve WA6ZFT

Gang, Probably, most of you know about the Graf series of books titled "Encyclopedia of Electronics" with volumes 1 through 6. Just about anything you are looking for may be in there. Crystal oscillators to sirens. Amplifiers of all types and the list goes on. All six volumes are on archive.org and are downloadable. If you are looking for something to do, then you should consider spending the next three or four months reading these in your spare time. You wont have any spare time when you start. Been there. Done that. Or read them in place on the web. FYI chuck, aa7fo

It's a different environment today for simulation. I can't run LTSpice on my ARM based Orange Pi 5 Plus like I can on the 32 processor Intel. But I can run ngspice for circuit analysis just fine. But, for grins, I asked DeepSeek to give me the tuning range for the values KD1JV was using for the ADC-40 receiver BPF in the front end. That's reason for the order for trimmers. Was getting different values than the BOM (which is changing daily and the reason I don't like doing one until the project is complete). So, the point, no more cranking up simulation and for getting the slide rule out for some things. Just type in a simple question and out comes the analysis and the values. Try this on the AI of your choice. Given L=12 micro Henry. What is the resonant frequencies for C=30pF and 5pF? For DeepSeek I'm impressed. It shows each step. Kids in the engineering and the sciences don't have to do homework anymore. Didn't try the others. Also, I use the turns calculator for toroids on KitsAndParts.com and compared with DeepSeek and results were slightly different, but good enough for starting assembly. FYI -- chuck adams, aa7fo WAS started Apr 2, 2025 at 5W. WAS-17 QRP --> TX,FL,SC,GA,OK,AR,KS,AL,AZ,PA,MN

Choices are Honbay or Acxico. Any preference or experiences with either or both? -- chuck adams, aa7fo WAS-17 QRP --> TX,FL,SC,GA,OK,AR,KS,AL,AZ

In the post earlier today about tariffs there was mentioned the pricing of solder. I have had good luck with picking up mostly full rolls of solder at garage sales or when the shop at work has to dispose of it because it "expires". I am sure many of you are familiar with similar industrial practices that adhere to strict shelf life requirements. I have used and or tested many of these rolls of solder, and they often work just fine. So the question is: Does it really expire, or more precisely, go bad? And yes, I am certainly familiar with the rosin vs acid core varieties and the leaded vs lead free. I do pay attention to that fact when picking up said items at garage sales. Sometimes I do want the acid core solder because I use it in the garage for different things. -Albert KI4ORI