ΜBITX - Revision history

Firespeaker: /* Mods planned */

2023-09-15T02:15:08Z

Mods planned

← Older revision		Revision as of 02:15, 15 September 2023
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	== Mods planned ==		== Mods planned ==
			* SWR meter (rx)

	~~=== Other things on wish list ===~~
	* ~~<s>~~SWR meter~~</s>~~
	** YL got me a DAIWA CN-501H for my birthday, 2021-03
	* Antenna analyser / antuino
	* Red-on-black or amber-on-black display (for night-time operation)		* Red-on-black or amber-on-black display (for night-time operation)
	** And/or a 6-8 digit LED display		** And/or a 6-8 digit LED display
	* More buttons - I like [https://www.bolkesteijn.nl/blog/index.php?page=ubitx-mods#ubitx-mod5 PH2LB's approach]!		* More buttons - I like [https://www.bolkesteijn.nl/blog/index.php?page=ubitx-mods#ubitx-mod5 PH2LB's approach] ([https://www.bolkesteijn.nl/blog/index.php?page=ubitx-mods3#ubitx-mod16 part 2])!
	** band up, band down, left/right digit selection for tuning, ...?		** band up, band down, left/right digit selection for tuning, ...?
	* Foot-pedal controlled TX		* Foot-pedal controlled TX
	** Have obtained an old (working) foot pedal switch for this purpose (edit: now have two)		** Have obtained an old (working) foot pedal switch for this purpose (edit: now have two somehow?)
	* Some sort of audio pre-processing?		* Some sort of audio pre-processing?
	* Fix filters??		* Fix filters??
			* line out
			** Again, [https://www.bolkesteijn.nl/blog/index.php?page=ubitx-mods3#ubitx-mod13 PH2LB's approach is great].

			=== Other things on wish list ===
			* <s>external SWR + power meter</s>
			** YL got me a DAIWA CN-501H for my birthday, 2021-03
			* Antenna analyser / antuino


	[[Category:Amateur radio]]		[[Category:Amateur radio]]

Firespeaker: /* Other things on wish list */

2023-09-15T01:57:11Z

Other things on wish list

← Older revision		Revision as of 01:57, 15 September 2023
Line 79:		Line 79:

	=== Other things on wish list ===		=== Other things on wish list ===
	* SWR meter		* <s>SWR meter</s>
			** YL got me a DAIWA CN-501H for my birthday, 2021-03
	* Antenna analyser / antuino		* Antenna analyser / antuino
	* Red-on-black or amber-on-black display (for night-time operation)		* Red-on-black or amber-on-black display (for night-time operation)
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	** band up, band down, left/right digit selection for tuning, ...?		** band up, band down, left/right digit selection for tuning, ...?
	* Foot-pedal controlled TX		* Foot-pedal controlled TX
	** Have obtained an old (working) foot pedal switch for this purpose		** Have obtained an old (working) foot pedal switch for this purpose (edit: now have two)
	* Some sort of audio pre-processing?		* Some sort of audio pre-processing?
	* Fix filters??		* Fix filters??

Firespeaker: /* Mods perfomed */

2022-08-14T02:13:52Z

Mods perfomed

← Older revision		Revision as of 02:13, 14 August 2022
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	=== Reducing harmonics ===		=== Reducing harmonics ===
	* [http://ubitx.net/spectral-purity/ Replaced relays with Axicom D2n 12v relays (model V23105-A5403-A201)]		* [http://ubitx.net/spectral-purity/ Replaced relays with Axicom D2n 12v relays (model V23105-A5403-A201)]

			=== Power measurements ===
			* Before and after the 3 mods above (levelling out power, reducing spurs, reducing harmonics)

			[[Image:µBitX mods power readings 2021-07.png]]

	== Mods planned ==		== Mods planned ==

Firespeaker: /* Antenna setup */

2022-08-14T02:02:43Z

Antenna setup

← Older revision		Revision as of 02:02, 14 August 2022
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	== Antenna setup ==		== Antenna setup ==

			=== 20m dipole ===

	Inverted V dipole made with Amateur Radio Supplies [https://www.amateurradiosupplies.com/product-p/20405.htm 20m dipole antenna wire] (two 18' strands, trimmed, wrapped around insulators, strung up in attic) and 450Ω window line.		Inverted V dipole made with Amateur Radio Supplies [https://www.amateurradiosupplies.com/product-p/20405.htm 20m dipole antenna wire] (two 18' strands, trimmed, wrapped around insulators, strung up in attic) and 450Ω window line.
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	QRPGuys [https://qrpguys.com/12w-dummy-load-power-meter 12W dummy load]		QRPGuys [https://qrpguys.com/12w-dummy-load-power-meter 12W dummy load]
	* Still no luck getting power measurements working.		* Still no luck getting power measurements working.
			* dummy load works when diode is removed (??)

	Items from QRPGuys took about 2 weeks from date of order to arrive.		Items from QRPGuys took about 2 weeks from date of order to arrive.

			=== 7-band OCF dipole ===

	Ordered [[7-band OCF dipole]] from gniklat1 on eBay.		Ordered [[7-band OCF dipole]] from gniklat1 on eBay.

Firespeaker: /* Mitigating heat on LM7805 */

2022-08-14T01:59:04Z

Mitigating heat on LM7805

← Older revision		Revision as of 01:59, 14 August 2022
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	I started by adding a small 5V switching power supply before LM7805. This created a ton of noise on RX, so I took it out.		I started by adding a small 5V switching power supply before LM7805. This created a ton of noise on RX, so I took it out.

	Instead, I relocated LM7805 to case (up against case and screwed to it). The first time I got the leads switched, though, and smoked the nano~~. This arrangement seems~~ to ~~dissipate heat nicely~~.		Instead, I relocated LM7805 to case (up against case and screwed to it). The first time I got the leads switched, though, and smoked the nano, so had to replace that.

	I also have a heatsink in ~~sold~~ old electronics that I've been meaning to try out too.		This arrangement seems to dissipate heat nicely.

			I also have a heatsink in some old electronics that I've been meaning to try out too.

	=== Dim the LCD ===		=== Dim the LCD ===

Firespeaker: /* Leveling out power */

2022-08-14T01:58:20Z

Leveling out power

← Older revision		Revision as of 01:58, 14 August 2022
Line 51:		Line 51:
	Replaced some of the transistors (etc.) per [http://ubitx.net/fix-fix-uneven-tx-output-across-bands/ this solution]:		Replaced some of the transistors (etc.) per [http://ubitx.net/fix-fix-uneven-tx-output-across-bands/ this solution]:

	* Replace the 2N3904 transistors in driver stages (Q911, Q912, Q92, Q93, Q96, Q97) with 2n2222 transistors (in a TO18 metal can)		* Replace the 2N3904 transistors in driver stages (Q911, Q912, Q92, Q93, Q96, Q97) with 2n2222 transistors (in TO18 metal can),
	* Parallel up R941, R911, R96, and R942 to get 11 ohms each by placing a 22 ohm resistor across each existing resistor~~. These resistors can easily be~~ stacked ~~if you use~~ 1206 ~~surface mount parts.~~		* Parallel up R941, R911, R96, and R942 to get 11 ohms each by placing a 22 ohm resistor across each existing resistor (stacked 1206),
	* Replace Q90 with a BFR106 transistor.		* Replace Q90 with a BFR106 transistor,
	* Increase R81 to 2.7K		* Increase R81 to 2.7K,
	* Change C81 to 470 pF		* Change C81 to 470 pF.

	=== Reducing spurs ===		=== Reducing spurs ===

Firespeaker at 01:57, 14 August 2022

2022-08-14T01:57:24Z

← Older revision		Revision as of 01:57, 14 August 2022
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	Soldered up red LED per [https://groups.io/g/BITX20/message/46853 BITX20 message 46853] on 2018-09-06. Works great!		Soldered up red LED per [https://groups.io/g/BITX20/message/46853 BITX20 message 46853] on 2018-09-06. Works great!

	== ~~Mods planned~~ ==		=== Leveling out power ===
			Replaced some of the transistors (etc.) per [http://ubitx.net/fix-fix-uneven-tx-output-across-bands/ this solution]:

	~~=== Leveling out power ===~~		* Replace the 2N3904 transistors in driver stages (Q911, Q912, Q92, Q93, Q96, Q97) with 2n2222 transistors (in a TO18 metal can)
	~~Planning on replacing some of~~ the transistors ~~per [http://ubitx~~.~~net/fix-fix-uneven-tx-output-across-bands/ this solution]~~.		* Parallel up R941, R911, R96, and R942 to get 11 ohms each by placing a 22 ohm resistor across each existing resistor. These resistors can easily be stacked if you use 1206 surface mount parts.
			* Replace Q90 with a BFR106 transistor.
			* Increase R81 to 2.7K
			* Change C81 to 470 pF

	=== Reducing spurs ===		=== Reducing spurs ===
	* [http://ubitx.net/2018/10/10/rajs-second-spurs-mod-simpler-again/ ~~Replace~~ L5 and L7]		* [http://ubitx.net/2018/10/10/rajs-second-spurs-mod-simpler-again/ Replaced L5 and L7]

	=== Reducing harmonics ===		=== Reducing harmonics ===
	* [http://ubitx.net/spectral-purity/ ~~Replace~~ relays with Axicom D2n 12v relays (model V23105-A5403-A201)]		* [http://ubitx.net/spectral-purity/ Replaced relays with Axicom D2n 12v relays (model V23105-A5403-A201)]

			== Mods planned ==


	=== Other things on wish list ===		=== Other things on wish list ===

Firespeaker: /* Antenna setup */

2020-09-22T22:49:55Z

Antenna setup

← Older revision		Revision as of 22:49, 22 September 2020
Line 20:		Line 20:
	Items from QRPGuys took about 2 weeks from date of order to arrive.		Items from QRPGuys took about 2 weeks from date of order to arrive.

	Ordered 7-band OCF dipole from gniklat1 on eBay.		Ordered [[7-band OCF dipole]] from gniklat1 on eBay.

	== Mods perfomed ==		== Mods perfomed ==

Firespeaker: /* Antenna setup */

2020-09-22T22:49:46Z

Antenna setup

← Older revision		Revision as of 22:49, 22 September 2020
Line 19:		Line 19:

	Items from QRPGuys took about 2 weeks from date of order to arrive.		Items from QRPGuys took about 2 weeks from date of order to arrive.

			Ordered 7-band OCF dipole from gniklat1 on eBay.

	== Mods perfomed ==		== Mods perfomed ==

Firespeaker: /* Dim the LCD */

2020-08-06T19:08:12Z

Dim the LCD

← Older revision		Revision as of 19:08, 6 August 2020
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	=== Dim the LCD ===		=== Dim the LCD ===
			[https://ubitx.net/2018/02/10/reducing-display-brightness/ As documented here].
	At first it had no effect, but then found I hadn't cut the trace between the two leads first, which I did 2018-09-06.		At first it had no effect, but then found I hadn't cut the trace between the two leads first, which I did 2018-09-06.